@article {2206, title = {Analysis of the high cracking resistance of a Co Ni superalloy during laser additive manufacturing}, journal = {Scripta Materialia}, volume = {239}, year = {2024}, pages = {115770}, abstract = {

A newly developed CoNi-based superalloy is demonstrated to be tolerant of a wide range of laser powder bed fusion print conditions, with limited defect content and high relative densities. These promising traits motivated investigation of the structural uniformity in samples printed at the upper end of the scan velocity processing window (\>Image 1). A new misorientation metric, starting reference orientation deviation (SROD), was calculated from Image 2-scale 3D microstructure information to examine structure evolution during epitaxial growth of columnar grains. Misorientations of \>20\° were observed within the large columnar grains that grew through multiple build layers. The SROD observations highlight the CoNi superalloy\&$\#$39;s ability to plastically deform to high levels, as evidenced by misorientation gradients, across the range of temperatures experienced in laser additive manufacturing. Misorientation gradients within the columnar grain structure are high relative to Ni base superalloys, allowing for strengthening with high volume fractions of L12 precipitates.

}, keywords = {3D EBSD, Rapid solidification, Superalloy}, issn = {1359-6462}, doi = {https://doi.org/10.1016/j.scriptamat.2023.115770}, url = {https://www.sciencedirect.com/science/article/pii/S1359646223004918}, author = {James Lamb and Kira M. Pusch and Andrew T. Polonsky and St{\'e}phane A.J. Forsik and Ning Zhou and Austin D. Dicus and Remco Geurts and McLean P. Echlin and Tresa M. Pollock} } @article {2216, title = {High Temperature B2 Precipitation in Ru-Containing Refractory Multi-principal Element Alloys}, journal = {Metallurgical and Materials Transactions A}, year = {2024}, abstract = {

Ru-based B2 phases present an opportunity to design two-phase BCC + B2 refractory multi-principal element alloys (RMPEAs) with higher temperature stability compared to B2 phases observed in RMPEAs. In this investigation, seven equiatomic Ru-containing RMPEAs were characterized in the as-cast and annealed conditions. Of the two Hf-free alloys, Mo$$_25$$Nb$$_25$$Ta$$_25$$Ru$$_25$$was determined to be a single-phase B2 alloy and Mo$$_20$$Nb$$_20$$Ta$$_20$$W$$_20$$Ru$$_20$$was single-phase BCC. Within all five Hf-containing alloys, phases formed during solidification included HfRu\–B2, disordered BCC, and HfO$$_{2}$$phases. The Hf-containing alloys also precipitated B2 nanoparticles within the BCC phases after further cooling in the solid. All phases were still present after annealing at 1500 $$^\circ$$C to 1600 $$^\circ$$C. The HfRu\–B2 nanoparticles in as-cast Hf$$_20$$Mo$$_20$$Nb$$_20$$Ta$$_20$$Ru$$_20$$were characterized by transmission electron microscopy (TEM), and a lattice misfit of \< 1 pct between the BCC phase and B2 nanoparticles was calculated. Room-temperature micropillar compression tests were performed on BCC + B2 nanoparticle regions in annealed Hf$$_20$$Mo$$_20$$Nb$$_20$$Ta$$_20$$Ru$$_20$$. Post-mortem TEM analysis revealed precipitate shearing by dislocations, resulting in paired dislocations, along with bowing of dislocations around precipitates. Utilizing the insights from this investigation, compositions for RMPEAs with solutionable B2 precipitates stable above 1200 $$^\circ$$C are suggested.

}, issn = {1543-1940}, doi = {10.1007/s11661-024-07368-x}, url = {https://doi.org/10.1007/s11661-024-07368-x}, author = {Frey, Carolina and You, Haojun and Kube, Sebastian and Balbus, Glenn H and Mullin, Kaitlyn and Oppenheimer, Scott and Holgate, Collin S and Pollock, Tresa M} } @article {2196, title = {Navigating the BCC-B2 refractory alloy space: Stability and thermal processing with Ru-B2 precipitates}, journal = {Acta Materialia}, volume = {265}, year = {2024}, pages = {119628}, abstract = {

Refractory multi-principal element alloys (RMPEAs) could provide next-generation high temperature alloys, but their ductility and high temperature strength need significant improvement. Emulating superalloy \γ-\γ\’ microstructures, RMPEAs combining a ductile BCC matrix with embedded B2 precipitates for strengthening could meet this goal. Two-phase BCC-B2 RMPEAs have recently been demonstrated, but the B2 phase typically exhibits insufficient thermodynamic stability for operating temperatures \≥1300 \°C. Using high-throughput CALPHAD predictions, we screen across 3,500 potential BCC-B2 systems. Promising compositions are predicted for alloys combining Ru-based B2s with refractory BCC elements. A total of 20 such compositions were arc-melted to characterize their as-cast and heat-treated microstructures. In these alloys, the RuHf B2 exhibits exceptional stability beyond 1900 \°C but cannot be solutionized. By contrast, RuTi does solutionize and reprecipitate between 1300 and 1900 \°C, providing a robust thermal processing pathway. RuAl can be solutionized but also tends to form competing intermetallic phases. Altogether, Ru-B2 RMPEAs offer great design flexibility and surpass the stability and thermal processability of previously studied BCC-B2 refractory alloys.

}, keywords = {B2 phase, Calphad, Combinatorial, High temperature materials, Precipitation strengthening, Refractory multi principal element alloys, Thermal processing}, issn = {1359-6454}, doi = {https://doi.org/10.1016/j.actamat.2023.119628}, url = {https://www.sciencedirect.com/science/article/pii/S1359645423009564}, author = {Sebastian A. Kube and Carolina Frey and Chiyo McMullin and Ben Neuman and Kaitlyn M. Mullin and Tresa M. Pollock} } @article {2211, title = {Rapid Screening of Single Phase Refractory Alloys Under Laser Melting Conditions}, journal = {Materials \& Design}, year = {2024}, pages = {112726}, abstract = {

Refractory alloys can be difficult to fabricate by laser-based manufacturing methods due to their high melting temperatures, high interstitial solubility, and propensity for low temperature brittleness. Laser-based processes, such as welding and additive manufacturing (AM), yield similar populations of defects, including microsegregation and solidification and solid-state cracking. Given the extreme challenges and cost associated with the production of refractory powders, this research aimed to develop a rapid screening methodology that combines predictive defect formation metrics with single track melting experiments. A flexible single laser track melting platform was designed to perform screening experiments on conventional and multi-principal element refractory alloys across a wide range of laser energy inputs. The platform was employed to investigate laser melting on solid substrates, or on a substrate with a single layer of powder feedstock, and is demonstrated with the highly fabricable Nb-base alloy C103. Preliminary investigations are performed on refractory multi-principal element alloys in the Hf-Mo-Nb-Ta-Ti family, and significant differences in cracking resistance and solidification morphology are observed. Implications for future alloy design and processing strategies for defect-resistant refractory alloys for AM are discussed.

}, keywords = {Additive manufacturing, high entropy alloy, multi-principal element alloy, refractory alloys, solid-state cracking, solidification cracking}, issn = {0264-1275}, doi = {https://doi.org/10.1016/j.matdes.2024.112726}, url = {https://www.sciencedirect.com/science/article/pii/S0264127524000984}, author = {Kaitlyn M. Mullin and Carolina Frey and James Lamb and Sophia K. Wu and McLean P. Echlin and Tresa M. Pollock} } @article {2201, title = {Strength vs temperature for refractory complex concentrated alloys (RCCAs): A critical comparison with refractory BCC elements and dilute alloys}, journal = {Acta Materialia}, volume = {266}, year = {2024}, pages = {119692}, abstract = {

To support the development of refractory complex, concentrated alloys (RCCAs), a clear understanding of the effect of temperature on strength is needed. Body-centered cubic (BCC) refractory metals and dilute refractory alloys show a strong temperature dependence of yield stress (\σy) at low and high temperatures, with a relatively temperature-independent regime in between. RCCAs may introduce important changes in deformation and strengthening mechanisms, so it is not clear if RCCAs will show the same thermal dependencies. The objective of this work is to answer the question, \“Is the temperature dependence of strength similar or different for RCCAs compared to BCC refractory elements and dilute refractory alloys ?\” We evaluate \σy vs. temperature for 61 RCCAs by analyzing data curated from the literature. We find that \σy increases progressively from refractory BCC elements, to dilute alloys, to single- and multi-phase RCCAs. Single-phase RCCAs show the same three thermal regimes, but the stresses are higher and the intermediate plateau is shorter and is sometimes steeper. The thermal dependence of \σy in multi-phase RCCAs shows more substantial differences. Six factors that contribute to the higher \σy of RCCAs are discussed: (i) higher solute concentration; (ii) dispersion in atomic sizes; (iii) the shear modulus magnitude; (iv) the type of principal elements; (v) the solvus temperature of predicted secondary phases; and (vi) microstructure. Based on the present observations and analyses, suggestions for future research are made, especially regarding improved models for the effect of temperature on strength.

}, keywords = {High-entropy alloys, Refractory complex concentrated alloys (RCCAs), Temperature effects, Yield strength}, issn = {1359-6454}, doi = {https://doi.org/10.1016/j.actamat.2024.119692}, url = {https://www.sciencedirect.com/science/article/pii/S1359645424000454}, author = {D.B. Miracle and O.N. Senkov and C. Frey and S. Rao and T.M. Pollock} } @article {1871, title = {Decoupling build orientation-induced geometric and texture effects on the mechanical response of additively manufactured IN625 thin-walled elements}, journal = {Materials Science and Engineering: A}, volume = {870}, year = {2023}, month = {02}, pages = {144826}, doi = {10.1016/j.msea.2023.144826}, author = {Banerjee, Arunima and Rossin, Jeff and He, Mo-Rigen and Musinski, William and Shade, Paul and Cox, Marie and Schwalbach, Edwin and Pollock, Tresa and Hemker, K.} } @article {1866, title = {Dislocation cells in additively manufactured metallic alloys characterized by electron backscatter diffraction pattern sharpness}, journal = {Materials Characterization}, volume = {197}, year = {2023}, month = {03}, pages = {112673}, doi = {10.1016/j.matchar.2023.112673}, author = {Wang, Fulin and Stinville, Jean-Charles and Charpagne, Marie-agathe and Echlin, Mclean and Agnew, Sean and Pollock, Tresa and Graef, Marc and Gianola, Daniel} } @article {1856, title = {Foreword: {\textquotedblleft}Eurosuperalloys 2022{\textquotedblright}}, journal = {Metallurgical and Materials Transactions A}, volume = {54}, year = {2023}, month = {03}, doi = {10.1007/s11661-023-07021-z}, author = {Cormier, Jonathan and Pollock, Tresa} } @article {1906, title = {In situ crack opening displacement growth rates of SiC/SiC ceramic matrix minicomposites}, journal = {Journal of the European Ceramic Society}, volume = {43}, year = {2023}, month = {02}, doi = {10.1016/j.jeurceramsoc.2023.01.061}, author = {Muir, C. and Swaminathan, B. and Musaffar, Abed and McCarthy, N.R. and Almansour, Amjad and Pollock, T.m. and Kiser, J.D. and Smith, C. and Daly, S. and Sevener, Kathleen} } @article {1846, title = {Inducing skyrmion flop transitions in Co 8 Zn 8 Mn 4 at room temperature}, journal = {Physical Review Materials}, volume = {7}, year = {2023}, month = {04}, doi = {10.1103/PhysRevMaterials.7.044401}, author = {Meynell, Simon and Eggeler, Yolita and Bocarsly, Joshua and Kitchaev, Daniil and Rhodes, Bailey and Pollock, Tresa and Wilson, Stephen and Ven, Anton and Seshadri, Ram and Graef, Marc and Jayich, Ania and Gianola, Daniel} } @article {1841, title = {Insights into Plastic Localization by Crystallographic Slip from Emerging Experimental and Numerical Approaches}, journal = {Annual Review of Materials Research}, volume = {53}, year = {2023}, month = {07}, pages = {275-317}, doi = {10.1146/annurev-matsci-080921-102621}, author = {Stinville, Jean-Charles and Charpagne, Marie-agathe and Maa{\ss}, Robert and Proudhon, Henry and Ludwig, W. and Callahan, P.G. and Wang, Fulin and Beyerlein, I.J. and Echlin, M.P. and Pollock, T.m.} } @article {1886, title = {Minor Elements and Solidification Cracking During Laser Powder-Bed Fusion of a High γ' CoNi-Base Superalloy}, journal = {Metallurgical and Materials Transactions}, volume = {54}, year = {2023}, month = {02}, pages = {1-14}, doi = {10.1007/s11661-023-06957-6}, author = {Raeker, Evan and Pusch, Kira and Forsik, St{\'e}phane and Zhou, Ning and Dicus, Austin and Ren, Qing-Qiang and Poplawsky, Jonathan and Kirka, M. and Pollock, Tresa} } @article {1881, title = {Morphological Stability of Solid-Liquid Interfaces Under Additive Manufacturing Conditions}, journal = {Acta Materialia}, volume = {250}, year = {2023}, month = {03}, pages = {118858}, doi = {10.1016/j.actamat.2023.118858}, author = {Tourret, Damien and Klemm-Toole, Jonah and Eres-Castellanos, Adriana and Rodgers, Brian and Becker, Gus and Saville, Alec and Ellyson, Ben and Johnson, Chloe and Milligan, Brian and Copley, John and Ochoa, Ruben and Polonsky, Andrew and Pusch, Kira and Haines, Michael and Fezzaa, Kamel and Sun, Tao and Clarke, Kester and Babu, Suresh and Pollock, Tresa and Clarke, Amy} } @article {1901, title = {Nondestructive quantification of single crystal elasticity for additively manufactured SB-CoNi-10C, IN625, and Ti64}, journal = {NDT \& E International}, volume = {135}, year = {2023}, month = {02}, pages = {102803}, doi = {10.1016/j.ndteint.2023.102803}, author = {Rossin, Jeff and Leser, Patrick and Benzing, Jake and Torbet, Chris and Dillon, Robert and Smith, Stephen and Daly, Samantha and Pollock, Tresa} } @article {1831, title = {Perspective: Large Language Models in Applied Mechanics}, journal = {Journal of Applied Mechanics}, volume = {90}, year = {2023}, month = {06}, pages = {1-12}, doi = {10.1115/1.4062773}, author = {Brodnik, Neal and Carton, Samuel and Muir, Caelin and Ghosh, Satanu and Downey, Doug and Echlin, Mclean and Pollock, Tresa and Daly, Samantha} } @article {1851, title = {Perspective: Machine learning in experimental solid mechanics}, journal = {Journal of the Mechanics and Physics of Solids}, volume = {173}, year = {2023}, month = {04}, pages = {105231}, doi = {10.1016/j.jmps.2023.105231}, author = {Brodnik, N.R. and Muir, C. and Tulshibagwale, N. and Rossin, J. and Echlin, M.P. and Hamel, C.M. and Kramer, S.L.B. and Pollock, T.m. and Kiser, J.D. and Smith, C. and Daly, S.H.} } @article {1891, title = {Quantitative Benchmarking of Acoustic Emission Machine Learning Frameworks for Damage Mechanism Identification}, journal = {Integrating Materials and Manufacturing Innovation}, year = {2023}, month = {02}, pages = {1-12}, doi = {10.1007/s40192-023-00293-8}, author = {Muir, C. and Tulshibagwale, N. and Furst, A. and Swaminathan, B. and Almansour, Amjad and Sevener, Kathleen and Presby, Michael and Kiser, J. and Pollock, T. and Daly, S. and Smith, C.} } @article {1896, title = {Slip localization behavior at triple junctions in nickel-base superalloys}, journal = {Acta Materialia}, volume = {249}, year = {2023}, month = {02}, pages = {118801}, doi = {10.1016/j.actamat.2023.118801}, author = {Hestroffer, Jonathan and Stinville, Jean-Charles and Charpagne, Marie-agathe and Miller, Matthew and Pollock, Tresa and Beyerlein, Irene} } @conference {1836, title = {Titanium 3D Microstructure for Physics-based Generative Models: A Dataset and Primer}, year = {2023}, month = {07}, author = {Jangid, Devendra and Brodnik, Neal and Echlin, Mclean and Daly, Samantha and Pollock, Tresa and Manjunath, B.} } @article {2016, title = {3D Grain Shape Generation in Polycrystals Using Generative Adversarial Networks}, journal = {Integrating Materials and Manufacturing Innovation}, volume = {11}, year = {2022}, month = {01}, doi = {10.1007/s40192-021-00244-1}, author = {Jangid, Devendra and Brodnik, Neal and Khan, Amil and Goebel, Michael and Echlin, Mclean and Pollock, Tresa and Daly, Samantha and Manjunath, B.} } @article {1911, title = {Adaptable physics-based super-resolution for electron backscatter diffraction maps}, journal = {npj Computational Materials}, volume = {8}, year = {2022}, month = {12}, doi = {10.1038/s41524-022-00924-2}, author = {Jangid, Devendra and Brodnik, Neal and Goebel, Michael and Khan, Amil and Majeti, SaiSidharth and Echlin, Mclean and Daly, Samantha and Pollock, Tresa and Manjunath, B.} } @article {1986, title = {Boundary characterization using 3D mapping of geometrically necessary dislocations in AM Ta microstructure}, journal = {Journal of Materials Science}, volume = {57}, year = {2022}, month = {06}, doi = {10.1007/s10853-022-07074-2}, author = {Witzen, Wyatt and Polonsky, Andrew and Rottmann, Paul and Pusch, Kira and Echlin, Mclean and Pollock, Tresa and Beyerlein, Irene} } @article {1946, title = {Damage Nucleation During Transverse Creep of a Directionally Solidified Ni-based Superalloy}, journal = {Materials Science and Engineering A}, volume = {858}, year = {2022}, month = {09}, pages = {144089}, doi = {10.1016/j.msea.2022.144089}, author = {Cormier, Jonathan and Stinville, Jean-Charles and Mataveli Suave, Lorena and Mauget, Florent and Patrick, Villechaise and Marcin, Lionel and Pollock, Tresa} } @article {1921, title = {Data-driven Bayesian model-based prediction of fatigue crack nucleation in Ni-based superalloys}, journal = {npj Computational Materials}, volume = {8}, year = {2022}, month = {12}, doi = {10.1038/s41524-022-00727-5}, author = {Pinz, Maxwell and Weber, George and Stinville, Jean-Charles and Pollock, Tresa and Ghosh, Somnath} } @article {1961, title = {Determination of peak ordering in the CrCoNi medium-entropy alloy via nanoindentation}, journal = {Acta Materialia}, volume = {241}, year = {2022}, month = {09}, pages = {118380}, doi = {10.1016/j.actamat.2022.118380}, author = {Zhang, Mingwei and Yu, Qin and Frey, Carolina and Walsh, Flynn and Payne, Madelyn and Kumar, Punit and Liu, Dongye and Pollock, Tresa and Asta, Mark and Ritchie, Robert and Minor, Andrew} } @article {2026, title = {Development of grain-scale slip activity and lattice rotation fields in Inconel 718}, journal = {Acta Materialia}, volume = {226}, year = {2022}, month = {01}, pages = {117627}, doi = {10.1016/j.actamat.2022.117627}, author = {Hestroffer, Jonathan and Latypov, Marat and Stinville, Jean-Charles and Charpagne, Marie-agathe and Valle, Valery and Miller, Matthew and Pollock, Tresa and Beyerlein, Irene} } @article {2021, title = {Experimental investigation and thermodynamic modelling of the Mg{\textendash}Al-rich region of the Mg{\textendash}Al{\textendash}Sr System}, journal = {International Journal of Materials Research}, volume = {97}, year = {2022}, month = {01}, pages = {422-428}, doi = {10.1515/ijmr-2006-0070}, author = {Cao, Hongbo and Zhu, Jun and Zhang, Chuan and Wu, Kaisheng and Saddock, Nicholas and Jones, J. and Pollock, Tresa and Schmid-Fetzer, Rainer and Chang, Y.} } @article {1796, title = {Grain-Scale Stress States in Microtextured Ti64: Implications for Dwell Fatigue}, journal = {Jom}, volume = {74}, year = {2022}, pages = {3709{\textendash}3719}, abstract = {

The room-temperature fatigue life of titanium alloys with a significant alpha phase fraction is substantially reduced when the peak stress is sustained for a few minutes on each stress cycle. Furthermore, these alloys often form microtextured regions during forging which are known to increase the dwell debit; however, the mechanisms for this reduction are still not well understood. In this research, an experimentally collected 3D microstructure of equiaxed Ti-6Al-4V containing microtextured regions is used as input for linear elastic finite element analysis of grain-level stress states relevant to dwell fatigue. The directional strength to stiffness ratio and a metric related to local plane strain are evaluated around the microtextured regions. Strength to stiffness ratios indicate that misoriented grains within hard microtextured regions will begin to yield at macroscopic stress levels below the yield strength, and, under certain loading conditions, they will yield at lower macroscopic stresses than any other location in the microstructure. Under uniaxial tension, boundaries between hard and soft microtextured regions experience some degree of plane strain loading, which may be linked to enhanced load shedding in these areas during dwell fatigue.

}, isbn = {1183702205}, issn = {15431851}, doi = {10.1007/s11837-022-05423-9}, url = {https://doi.org/10.1007/s11837-022-05423-9}, author = {Wendorf, Joe and Dawson, Paul R. and Pollock, Tresa M.} } @article {1956, title = {Heterogeneous slip localization in an additively manufactured 316L stainless steel}, journal = {International Journal of Plasticity}, volume = {159}, year = {2022}, month = {09}, pages = {103436}, doi = {10.1016/j.ijplas.2022.103436}, author = {Bean, Christopher and Wang, Fulin and Charpagne, Marie-agathe and Villechaise, P. and Valle, Valery and Agnew, S.R. and Gianola, D.S. and Pollock, T.m. and Stinville, Jean-Charles} } @article {2011, title = {A high stability B2-containing refractory multi-principal element alloy}, journal = {Acta Materialia}, volume = {229}, year = {2022}, month = {03}, pages = {117767}, doi = {10.1016/j.actamat.2022.117767}, author = {Frey, Carolina and Silverstein, Ravit and Pollock, Tresa} } @article {1981, title = {In Situ X-ray Radiography and Computational Modeling to Predict Grain Morphology in β-Titanium during Simulated Additive Manufacturing}, journal = {Metals}, volume = {12}, year = {2022}, month = {07}, pages = {1217}, doi = {10.3390/met12071217}, author = {Jasien, Chris and Saville, Alec and Becker, Chandler and Klemm-Toole, Jonah and Fezzaa, Kamel and Sun, Tao and Pollock, Tresa and Clarke, Amy} } @article {1931, title = {Materials for extreme environments}, journal = {Nature Reviews Materials}, volume = {8}, year = {2022}, month = {11}, doi = {10.1038/s41578-022-00496-z}, author = {Eswarappa Prameela, Suhas and Pollock, Tresa and Raabe, Dierk and Meyers, Marc and Aitkaliyeva, Assel and Chintersingh, Kerri-Lee and Cordero, Zachary and Graham-Brady, Lori} } @article {1971, title = {Merging Machine Learning and TriBeam Tomography for 3D Defect Detection in an AM CoNi-Based Superalloy}, journal = {Microscopy and Microanalysis}, volume = {28}, year = {2022}, month = {08}, pages = {862-863}, doi = {10.1017/S1431927622003828}, author = {Lamb, James and Echlin, Mclean and Polonsky, Andrew and Geurts, Remco and Pusch, Kira and Raeker, Evan and Botman, Aurelien and Torbet, Chris and Pollock, Tresa} } @article {1996, title = {Microstructure Evolution and Tensile Properties of a Selectively Laser Melted CoNi-Base Superalloy}, journal = {Metallurgical and Materials Transactions A}, volume = {53}, year = {2022}, month = {05}, doi = {10.1007/s11661-022-06716-z}, author = {Murray, Sean and Raeker, Evan and Pusch, Kira and Frey, Carolina and Torbet, Chris and Zhou, Ning and Forsik, St{\'e}phane and Dicus, Austin and Colombo, Gian and Kirka, M. and Pollock, Tresa} } @article {1966, title = {Multi-modal Dataset of a Polycrystalline Metallic Material: 3D Microstructure and Deformation Fields}, journal = {Scientific Data}, volume = {9}, year = {2022}, month = {08}, doi = {10.1038/s41597-022-01525-w}, author = {Stinville, Jean-Charles and Hestroffer, Jonathan and Charpagne, Marie-agathe and Polonsky, Andrew and Echlin, M. and Torbet, Chris and Valle, Valery and Nygren, K. and Miller, M. and Klaas, Ottmar and Loghin, Adrian and Beyerlein, I. and Pollock, T.} } @article {1941, title = {Nucleation of recrystallization in magnesium alloy grains of varied orientation and the impacts on texture evolution}, journal = {Journal of Magnesium and Alloys}, volume = {10}, year = {2022}, month = {10}, doi = {10.1016/j.jma.2022.09.006}, author = {Miller, Victoria and Nie, J.F. and Pollock, Tresa} } @article {2006, title = {Observation of bulk plasticity in a polycrystalline titanium alloy by diffraction contrast tomography and topotomography}, journal = {Materials Characterization}, volume = {188}, year = {2022}, month = {04}, pages = {111891}, doi = {10.1016/j.matchar.2022.111891}, author = {Stinville, Jean-Charles and Ludwig, Wolfgang and Callahan, P.G. and Echlin, M.P. and Valle, Valery and Pollock, T.m. and Proudhon, Henry} } @article {1976, title = {Observations of Damage, Defects, and Structuring in Femtosecond Laser Ablated Surfaces}, journal = {Microscopy and Microanalysis}, volume = {28}, year = {2022}, month = {08}, pages = {872-873}, doi = {10.1017/S1431927622003865}, author = {Echlin, Mclean and Polonsky, Andrew and Lenthe, Will and Titus, Mike and Geurts, Remco and Botman, Aurelien and Straw, Marcus and Gumbsch, Peter and Pollock, Tresa} } @article {2001, title = {Orientation dependent plastic localization in the refractory high entropy alloy HfNbTaTiZr at room temperature}, journal = {Materials Science and Engineering: A}, volume = {848}, year = {2022}, month = {05}, pages = {143291}, doi = {10.1016/j.msea.2022.143291}, author = {Charpagne, Marie-agathe and Stinville, Jean-Charles and Wang, Fulin and Philips, Noah and Pollock, T.m.} } @article {1951, title = {On the origins of fatigue strength in crystalline metallic materials}, journal = {Science}, volume = {377}, year = {2022}, month = {09}, pages = {1065-1071}, doi = {10.1126/science.abn0392}, author = {Stinville, Jean-Charles and Charpagne, Marie-agathe and Cervellon, Alice and H{\'e}mery, Samuel and Wang, Fulin and Callahan, P. and Valle, Valery and Pollock, T.} } @article {1991, title = {Scan strategies in EBM-printed IN718 and the physics of bulk 3D microstructure development}, journal = {Materials Characterization}, volume = {190}, year = {2022}, month = {06}, pages = {112043}, doi = {10.1016/j.matchar.2022.112043}, author = {Polonsky, Andrew and Raghavan, Narendran and Echlin, Mclean and Kirka, M. and Dehoff, Ryan and Pollock, Tresa} } @article {1811, title = {Single crystal elastic constants of additively manufactured components determined by resonant ultrasound spectroscopy}, journal = {Materials Characterization}, volume = {192}, year = {2022}, pages = {112244}, abstract = {

Bayesian inference with Sequential Monte Carlo was used to determine the single crystal elastic constants of additively manufactured (AM) cobalt-nickel-based superalloy specimens from only the resonant frequencies and texture data. This novel framework enables the quantification of the single crystal elastic constants for AM and polycrystalline specimens using only electron backscatter diffraction (EBSD) and Resonant Ultrasound Spectroscopy (RUS), avoiding the expense of bulk single crystal fabrication or synchrotron experiments. A parallelizable and open-source Python package (SMCPy) was used to perform Bayesian inference of the single crystal elastic constants from resonant frequencies of AM specimens. The single crystal elastic constants determined from AM cobalt-nickel-base superalloy specimens were validated with measurements of the single crystal elastic constants on a bulk single crystal specimen. EBSD texture data was used to determine the single crystal elastic constants from the resonant frequencies of AM specimens, and validated with neutron diffraction data by considering the experimental uncertainty in both the EBSD and neutron diffraction data. The robustness of this framework for varied texture orientations relative to the build direction (BD) was demonstrated for AM specimens printed at 0\° and 20\° BD-inclinations.

}, issn = {1044-5803}, doi = {https://doi.org/10.1016/j.matchar.2022.112244}, url = {https://www.sciencedirect.com/science/article/pii/S1044580322005265}, author = {Jeff Rossin and Patrick Leser and Kira Pusch and Carolina Frey and Sven C. Vogel and Alec I. Saville and Chris Torbet and Amy J. Clarke and Samantha Daly and Tresa M. Pollock} } @article {1936, title = {Subgrain geometrically necessary dislocation density mapping in spalled Ta in three dimensions}, journal = {Acta Materialia}, volume = {244}, year = {2022}, month = {11}, pages = {118366}, doi = {10.1016/j.actamat.2022.118366}, author = {Witzen, Wyatt and Echlin, Mclean and Charpagne, Marie-agathe and Pollock, Tresa and Beyerlein, Irene} } @article {1926, title = {Temperature-dependent tensile behavior of the HfNbTaTiZr multi-principal element alloy}, journal = {Acta Materialia}, volume = {245}, year = {2022}, month = {12}, pages = {118618}, doi = {10.1016/j.actamat.2022.118618}, author = {Mills, Leah and Emigh, Megan and Frey, Carolina and Philips, Noah and Murray, Sean and Shin, Jungho and Gianola, Daniel and Pollock, Tresa} } @conference {2061, title = {3D Characterization of the Columnar-to-Equiaxed Transition in Additively Manufactured Inconel 718.}, year = {2021}, month = {09}, doi = {10.2172/1886524}, author = {Polonsky, Andrew and Raghavan, Narendran and Echlin, Mclean and Kirka, Michael and Dehoff, Ryan and Pollock, Tresa} } @article {1741, title = {Bayesian inference of elastic constants and texture coefficients in additively manufactured cobalt-nickel superalloys using resonant ultrasound spectroscopy}, journal = {Acta Materialia}, volume = {220}, year = {2021}, pages = {117287}, abstract = {

Bayesian inference with sequential Monte Carlo is used to quantify the orientation distribution function coefficients and to calculate the fully anisotropic elastic constants of additively manufactured specimens from only the experimentally-measured resonant frequencies. The parallelizable and open-source SMCPy Python package enabled Bayesian inference within this new modeling framework, resulting in an order of magnitude reduction of the computation time for an 8-core machine. Residual stress-induced shifts on the resonant frequencies were explicitly accounted for during the Bayesian inference, enabling the estimation of their effect on the resonant frequencies without a stress-relief heat treatment. Additively manufactured cobalt-nickel-base superalloy (SB-CoNi-10C) specimens were sectioned at multiple inclinations relative to the build direction and scanned with resonant ultrasound spectroscopy to demonstrate characterization of any arbitrarily textured cubic microstructure through the resonant frequencies. The orientation distribution function coefficients of the textured polycrystalline microstructure were estimated in tensorial form to calculate both the 2nd order Hashin-Shtrikman bounds and the self-consistent estimate of the elastic constants, enabling accurate determination of all 21 possible independent elastic constants through the convergence constraints of the texture. Pole figures generated directly from the calculated texture coefficients showed good agreement with experimentally measured textures.

}, keywords = {Additive manufacturing, Bayesian inference, Parallel computing, Residual stress, Resonance ultrasound spectroscopy, Sequential monte carlo, Texture characterization}, issn = {1359-6454}, doi = {https://doi.org/10.1016/j.actamat.2021.117287}, url = {https://www.sciencedirect.com/science/article/pii/S1359645421006674}, author = {Jeff Rossin and Patrick Leser and Kira Pusch and Carolina Frey and Sean P. Murray and Chris J. Torbet and Stephen Smith and Samantha Daly and Tresa M. Pollock} } @article {2101, title = {Corrigendum to {\textquotedblleft}Defects and 3D structural inhomogeneity in electron beam additively manufactured Inconel 718{\textquotedblright} [Materials Characterization 143 (2018) 171{\textendash}181]}, journal = {Materials Characterization}, volume = {176}, year = {2021}, month = {06}, pages = {111069}, doi = {10.1016/j.matchar.2021.111069}, author = {Polonsky, Andrew and Echlin, Mclean and Lenthe, William and Dehoff, Ryan and Kirka, M. and Pollock, Tresa} } @article {2081, title = {Crack initiation anisotropy of Ni-based SX superalloys in the very high cycle fatigue regime}, journal = {Materials Science and Engineering: A}, volume = {825}, year = {2021}, month = {08}, pages = {141920}, doi = {10.1016/j.msea.2021.141920}, author = {Cervellon, Alice and Torbet, Chris and Pollock, Tresa} } @article {2121, title = {Crystallography and elastic anisotropy in fatigue crack nucleation at nickel alloy twin boundaries}, journal = {Journal of the Mechanics and Physics of Solids}, volume = {155}, year = {2021}, month = {06}, pages = {104538}, doi = {10.1016/j.jmps.2021.104538}, author = {Zhang, Xiaoxian and Stinville, Jean-Charles and Pollock, Tresa and Dunne, Fionn} } @article {2111, title = {Damage mechanism identification in composites via machine learning and acoustic emission}, journal = {npj Computational Materials}, volume = {7}, year = {2021}, month = {06}, pages = {95}, doi = {10.1038/s41524-021-00565-x}, author = {Muir, C. and Swaminathan, B. and Almansour, Amjad and Sevener, Kathleen and Smith, C. and Presby, Michael and Kiser, J. and Pollock, T. and Daly, S.} } @article {1681, title = {Damage mechanisms during very high cycle fatigue of a coated and grit-blasted Ni-based single-crystal superalloy}, journal = {International Journal of Fatigue}, volume = {142}, year = {2021}, abstract = {

The very high cycle fatigue properties of the Ni-based single-crystal superalloy CMSX-4 coated with an MCrAlY type coating and grit-blasted were studied at 1000 \°C, 20 kHz and R = -1. A recrystallized layer thicker than the size of the larger casting pores (\>50 \μm) drastically reduces the fatigue life without environmental influence. The recrystallized layer and roughness introduced by grit-blasting degrades the environmental resistance of the alloy and the resultant fatigue life. The fatigue life of the coated specimens is also greatly reduced from damage accumulation in the interdiffusion zone by grain boundary cracking, oxidation and internal nitridation.

}, keywords = {Coating, Oxidation, Recrystallization, Single-crystal superalloy, Very high cycle fatigue}, issn = {01421123}, doi = {10.1016/j.ijfatigue.2020.105962}, author = {Cervellon, Alice and Bortoluci Ormastroni, Luciana Maria and Hervier, Z{\'e}line and Pollock, Tresa M. and Pedraza, Fernando and Cormier, Jonathan} } @article {2186, title = {A Data-Driven Bayesian Model for Predicting Fatigue Crack Nucleation in Polycrystalline Ni-Based Superalloys}, journal = {SSRN Electronic Journal}, year = {2021}, month = {01}, doi = {10.2139/ssrn.3878357}, author = {Pinz, Maxwell and Weber, George and Stinville, Jean-Charles and Pollock, Tresa and Ghosh, Somnath} } @article {1686, title = {Electron backscattered diffraction using a new monolithic direct detector: High resolution and fast acquisition}, journal = {Ultramicroscopy}, volume = {220}, year = {2021}, pages = {113160}, abstract = {

A monolithic active pixel sensor based direct detector that is optimized for the primary beam energies in scanning electron microscopes is implemented for electron back-scattered diffraction (EBSD) applications. The high detection efficiency of the detector and its large array of pixels allow sensitive and accurate detection of Kikuchi bands arising from primary electron beam excitation energies of 4 keV to 28 keV, with the optimal contrast occurring in the range of 8\–16 keV. The diffraction pattern acquisition speed is substantially improved via a sparse sampling mode, resulting from the acquisition of a reduced number of pixels on the detector. Standard inpainting algorithms are implemented to effectively estimate the information in the skipped regions in the acquired diffraction pattern. For EBSD mapping, an acquisition speed as high as 5988 scan points per second is demonstrated, with a tolerable fraction of indexed points and accuracy. The collective capabilities spanning from high angular resolution EBSD patterns to high speed pattern acquisition are achieved on the same detector, facilitating simultaneous detection modalities that enable a multitude of advanced EBSD applications, including lattice strain mapping, structural refinement, low-dose characterization, 3D-EBSD and dynamic in situ EBSD.

}, keywords = {Direct detection, EBSD, Indexing, Inpainting, SEM, Sparse sampling}, issn = {18792723}, doi = {10.1016/j.ultramic.2020.113160}, url = {https://doi.org/10.1016/j.ultramic.2020.113160}, author = {Wang, Fulin and Echlin, Mclean P. and Taylor, Aidan A. and Shin, Jungho and Bammes, Benjamin and Levin, Barnaby D.A. and De Graef, Marc and Pollock, Tresa M. and Gianola, Daniel S.} } @article {2181, title = {A High Stability B2-Containing Refractory Multi-Principal Element Alloy}, journal = {SSRN Electronic Journal}, year = {2021}, month = {01}, doi = {10.2139/ssrn.3965527}, author = {Frey, Carolina and Silverstein, Ravit and Pollock, Tresa} } @article {2096, title = {High-throughput approach for estimation of intrinsic barriers in FCC structures for alloy design}, journal = {Scripta Materialia}, volume = {204}, year = {2021}, month = {07}, pages = {114126}, doi = {10.1016/j.scriptamat.2021.114126}, author = {Vamsi, K V and Charpagne, Marie-agathe and Pollock, Tresa} } @article {1661, title = {Influence of plastic deformation on the magnetic properties of Heusler MnAu2Al}, journal = {Phys. Rev. Materials}, volume = {5}, year = {2021}, month = {01/2021}, chapter = {014408}, abstract = {

The Heulser intermetallic\ MnAu2Al\ is shown to undergo a dramatic change in net magnetization in response to plastic deformation. A mechanism is proposed involving antiferromagnetic interactions in the otherwise ferromagnetic compound (when ordered) that arise due to chemical changes at the antiphase boundaries created by the deformation. The coupling between chemical and magnetic order across antiphase boundaries is likely to occur in other ordered magnetic systems and may provide an explanation for otherwise anomalous magnetic behavior across several systems, including other Heusler intermetallics.

}, doi = {https://doi.org/10.1103/PhysRevMaterials.5.014408}, url = {https://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.5.014408}, author = {Levin, Emily E. and Kitchaev, Daniil A. and Eggeler, Yolita M and Mayer, Justin A. and Behera, Piush and Gianola, Daniel S. and Van der Ven, Anton and Pollock, Tresa M. and Seshadri, Ram} } @article {1676, title = {Insight into microstructure-sensitive elastic strain concentrations from integrated computational modeling and digital image correlation}, journal = {Scripta Materialia}, volume = {192}, year = {2021}, pages = {78{\textendash}82}, abstract = {

The microstructural origins of highly localized elastic strain concentrations in polycrystalline microstructures under monotonic loading are studied using grain-scale, in situ digital image correlation and crystal plasticity finite element method. It is shown that the locations of exceptionally high elastic strain concentrations in the microstructure depend on particular crystallographic and morphological orientations of grains and less so on crystalline details of their local neighborhood. Based on these results, we discuss how topological and crystallographic features of annealing twin boundaries can increase the likelihood of slip band initiation throughout the microstructure of polycrystalline Ni-base superalloys.

}, keywords = {Elasticity, Micromechanics, Microstructure, Superalloys}, issn = {13596462}, doi = {10.1016/j.scriptamat.2020.10.001}, url = {https://doi.org/10.1016/j.scriptamat.2020.10.001}, author = {Latypov, Marat I. and Stinville, Jean Charles and Mayeur, Jason R. and Hestroffer, Jonathan M. and Pollock, Tresa M. and Beyerlein, Irene J.} } @article {2126, title = {Interpreting acoustic energy emission in SiC/SiC minicomposites through modeling of fracture surface areas}, journal = {Journal of the European Ceramic Society}, year = {2021}, month = {06}, doi = {10.1016/j.jeurceramsoc.2021.06.030}, author = {Swaminathan, B. and McCarthy, N. and Almansour, Amjad and Sevener, Kathleen and Musaffar, Abed and Pollock, T. and Kiser, J. and Daly, S.} } @article {1666, title = {Kink band and shear band localization in anisotropic perfectly plastic solids}, journal = {Journal of the Mechanics and Physics of Solids}, volume = {146}, year = {2021}, pages = {104183}, abstract = {

Shear-driven strain localization has been observed in a wide variety of materials and may take the form of shear bands or kink bands. Based on observations of kink bands in plastically anisotropic metallic nanolaminates and single crystal metals, we posit that, for the specific case of isochoric deformation, the kinematics of kink band formation are indistinguishable from those of plane strain shear band formation. The only distinction between shear bands and kink bands in these systems would then be that kink bands \‘lock up\&$\#$39; at a particular value of material rotation while shear bands may progress to arbitrarily high strains. In order to investigate whether strong material anisotropy is sufficient to arrest shear localization at a geometry that matches the classic kink band geometry, we model the development of a band of simple shear within an anisotropic perfectly plastic material. The resulting analytical model provides the stress state needed to maintain the kinematics of simple shear as a function of material anisotropy, deformation band orientation, and shear strain (or equivalently, material rotation). It is found that plastic anisotropy can promote either kink band or shear band formation depending on the loading orientation. When the deviatoric stress is positive parallel to the plane of anisotropy, shear localization may progress without bound and a shear band is produced. When the deviatoric stress is negative parallel to the plane of anisotropy, shear localization is arrested after a certain material rotation, resulting in a kink band. Examination of the requisite applied stress state during kink band formation provides an explanation for the experimentally-observed \‘lock up\&$\#$39; geometry. Solutions for the band boundary inclination angle are obtained and used to provide bounds on permissible band angles for both shear bands and kink bands.

}, keywords = {Anisotropic material (B), Ideally plastic material (B), Layered material (B), Shear localization}, issn = {00225096}, doi = {10.1016/j.jmps.2020.104183}, url = {https://doi.org/10.1016/j.jmps.2020.104183}, author = {Nizolek, Thomas J. and Pollock, Tresa M. and Mcmeeking, Robert M.} } @article {2156, title = {On the Localization of Plastic Strain in Microtextured Regions of Ti-6Al-4V}, journal = {Acta Materialia}, volume = {204}, year = {2021}, month = {02}, pages = {116492}, doi = {10.1016/j.actamat.2020.116492}, author = {Cappola, Jonathan and Stinville, Jean-Charles and Charpagne, Marie-agathe and Callahan, Patrick and Echlin, Mclean and Pollock, Tresa and Pilchak, Adam and Kasemer, Matthew} } @article {2056, title = {Low cycle fatigue of a single crystal CoNi-base superalloy}, journal = {Materials Science and Engineering A}, volume = {827}, year = {2021}, month = {09}, doi = {10.1016/j.msea.2021.142007}, author = {Murray, Sean and Cervellon, Alice and Cormier, Jonathan and Pollock, Tresa} } @article {2036, title = {A machine learning framework for damage mechanism identification from acoustic emissions in unidirectional SiC/SiC composites}, journal = {npj Computational Materials}, volume = {7}, year = {2021}, month = {12}, doi = {10.1038/s41524-021-00620-7}, author = {Muir, C. and Swaminathan, B. and Fields, K. and Almansour, Amjad and Sevener, Kathleen and Smith, C. and Presby, Michael and Kiser, J. and Pollock, T. and Daly, S.} } @article {2146, title = {Mechanical Metrics of Virtual Polycrystals (MechMet)}, journal = {Integrating Materials and Manufacturing Innovation}, volume = {10}, year = {2021}, month = {04}, pages = {1-21}, doi = {10.1007/s40192-021-00206-7}, author = {Dawson, Paul and Miller, Matthew and Pollock, Tresa and Wendorf, Joe and Mills, Leah and Stinville, Jean-Charles and Charpagne, Marie-agathe and Echlin, Mclean} } @article {2136, title = {Microscale Characterization of Damage Accumulation in CMCs}, journal = {Journal of the European Ceramic Society}, volume = {41}, year = {2021}, month = {05}, pages = {3082-3093}, doi = {10.1016/j.jeurceramsoc.2020.05.077}, author = {Swaminathan, B. and McCarthy, N. and Almansour, Amjad and Sevener, Kathleen and Pollock, T. and Kiser, J. and Daly, S.} } @article {2141, title = {Microstructure-Based Estimation of Strength and Ductility Distributions for α+β Titanium Alloys}, journal = {Metallurgical and Materials Transactions A}, year = {2021}, month = {04}, doi = {10.1007/s11661-021-06233-5}, author = {Echlin, Mclean and Kasemer, Matthew and Chatterjee, Kamalika and Boyce, Donald and Stinville, Jean-Charles and Callahan, Patrick and Wielewski, Euan and Park, Jun-Sang and Williams, James and Suter, Robert and Pollock, Tresa and Miller, Matthew and Dawson, Paul} } @article {2076, title = {Modeling lattice rotation fields from discrete crystallographic slip bands in superalloys}, journal = {Extreme Mechanics Letters}, volume = {49}, year = {2021}, month = {08}, pages = {101468}, doi = {10.1016/j.eml.2021.101468}, author = {Latypov, Marat and Hestroffer, Jonathan and Stinville, Jean-Charles and Mayeur, Jason and Pollock, Tresa and Beyerlein, Irene} } @article {2131, title = {Multimodal 3D Characterization of Voids in Shock-Loaded Tantalum: Implications for Ductile Spallation Mechanisms}, journal = {Acta Materialia}, volume = {215}, year = {2021}, month = {06}, pages = {117057}, doi = {10.1016/j.actamat.2021.117057}, author = {Francis, Toby and Rottmann, Paul and Polonsky, Andrew and Charpagne, Marie-agathe and Echlin, Mclean and Livescu, Veronica and Jones, David and Gray, G. and Graef, Marc and Pollock, Tresa} } @article {2051, title = {A Multi-modal Data Merging Framework for Correlative Investigation of Strain Localization in Three Dimensions}, journal = {JOM}, volume = {73}, year = {2021}, month = {09}, doi = {10.1007/s11837-021-04894-6}, author = {Charpagne, Marie-agathe and Stinville, Jean-Charles and Polonsky, Andrew and Echlin, M. and Pollock, T.} } @article {2086, title = {A new elastic characterization method for anisotropic bilayer specimens via Bayesian resonant ultrasound spectroscopy}, journal = {Ultrasonics}, volume = {115}, year = {2021}, month = {08}, pages = {106455}, doi = {10.1016/j.ultras.2021.106455}, author = {Goodlet, Brent and Bales, Ben and Pollock, Tresa} } @article {1761, title = {Precipitate Shearing, Fault Energies, and Solute Segregation to Planar Faults in Ni-, CoNi-, and Co-Base Superalloys}, journal = {Annual Review of Materials Research}, volume = {51}, year = {2021}, pages = {209-240}, abstract = {

The mechanical properties of superalloys are strongly governed by the resistance to shearing of ordered precipitates by dislocations. In the operating environments of superalloys, the stresses and temperatures present during thermomechanical loading influence the dislocation shearing dynamics, which involve diffusion and segregation processes that result in a diverse array of planar defects in the ordered L12 \γ\′ precipitate phase. This review discusses the current understanding of high-temperature deformation mechanisms of \γ\′ precipitates in two-phase Ni-, Co-, and CoNi-base superalloys. The sensitivity of planar fault energies to chemical composition results in a variety of unique deformation mechanisms, and methods to determine fault energies are therefore reviewed. The degree of chemical segregation in the vicinity of planar defects reveals an apparent phase transformation within the parent \γ\′ phase. The kinetics of segregation to linear and planar defects play a significant role in high-temperature properties. Understanding and controlling fault energies and the associated dislocation dynamics provide a new pathway for the design of superalloys with exceptional properties.

}, doi = {10.1146/annurev-matsci-102419-011433}, url = {https://doi.org/10.1146/annurev-matsci-102419-011433}, author = {Eggeler, Y.M. and Vamsi, K.V. and Pollock, T.m.} } @article {2046, title = {Recent Developments in Femtosecond Laser-Enabled TriBeam Systems}, journal = {JOM}, volume = {73}, year = {2021}, month = {11}, pages = {1-12}, doi = {10.1007/s11837-021-04919-0}, author = {Echlin, Mclean and Polonsky, Andrew and Lamb, James and Geurts, Remco and Randolph, Steven and Botman, Aurelien and Pollock, Tresa} } @article {2151, title = {Rejuvenation of Directionally Solidified and Single-Crystal Nickel-Base Superalloys}, journal = {Metallurgical and Materials Transactions A}, volume = {52}, year = {2021}, month = {03}, doi = {10.1007/s11661-021-06150-7}, author = {Rettberg, Luke and Callahan, P. and Goodlet, Brent and Pollock, T.} } @article {2106, title = {Slip localization in Inconel 718: A three-dimensional and statistical perspective}, journal = {Acta Materialia}, volume = {215}, year = {2021}, month = {06}, pages = {117037}, doi = {10.1016/j.actamat.2021.117037}, author = {Charpagne, Marie-agathe and Hestroffer, Jonathan and Polonsky, Andrew and Echlin, M.P. and Texier, Damien and Valle, Valery and Beyerlein, I.J. and Pollock, T.m. and Stinville, Jean-Charles} } @article {2071, title = {Strain Localization and Fatigue Crack Formation at ( 0001 ) Twist Boundaries in Titanium Alloys}, journal = {Acta Materialia}, volume = {219}, year = {2021}, month = {08}, pages = {117227}, doi = {10.1016/j.actamat.2021.117227}, author = {H{\'e}mery, Samuel and Stinville, Jean-Charles and Wang, Fulin and Charpagne, Marie-agathe and Emigh, M.G. and Pollock, T.m. and Valle, Valery} } @article {1671, title = {Temperature dependence of single crystal elastic constants in a CoNi-Base alloy: A new methodology}, journal = {Materials Science and Engineering A}, volume = {803}, year = {2021}, pages = {140507}, abstract = {

A novel experimental setup combining induction heating, contactless (infrared thermometer) temperature measurements, and custom 15 cm length SiC-tipped piezoelectric transducers has been developed to rapidly collect resonant ultrasound spectroscopy (RUS) data from metallic rectangular parallelepiped (RP) specimens heated in air. This setup is used to collect over 70 of the lowest-frequency resonance modes from a single crystal of the novel CoNi-based superalloy SB-CoNi-10+\—an alloy identified for further study due to a promising set of high temperature properties. RUS spectra from room temperature (RT) to 927 \°C (1200 K) along with dilatometry measurements of the thermal expansion behavior are supplied to a robust, open-sourced, Bayesian inference code for simultaneous estimation of: three single crystal elastic constants, three crystal axis misorientation parameters, and a noise parameter. This study is the first application of the Bayesian RUS methodology at elevated temperatures, and the first to characterize SB-CoNi-10+. A monotonic decrease in elastic constants (C11,C12,C44) from (236.4, 150.8, 134.1) GPa to (190.7, 138.1, 95.2) GPa and a 15\% increase in elastic anisotropy from A = 3.131 \→ 3.618 is observed upon heating from RT to 927 \°C, with an increased rate of softening above 600 \°C (873 K).

}, keywords = {Bayesian inference, Elastic constants, High-temperature, Resonant ultrasound spectroscopy, Single crystal, Superalloy}, issn = {09215093}, doi = {10.1016/j.msea.2020.140507}, url = {https://doi.org/10.1016/j.msea.2020.140507}, author = {Goodlet, Brent R. and Murray, Sean P. and Bales, Ben and Rossin, Jeff and Torbet, Chris J. and Pollock, Tresa M.} } @article {2116, title = {TriBeam tomography and microstructure evolution in additively manufactured Alnico magnets}, journal = {Materials Today}, volume = {49}, year = {2021}, month = {06}, doi = {10.1016/j.mattod.2021.05.003}, author = {Rottmann, Paul and Polonsky, Andrew and Francis, Toby and Emigh, Megan and Krispin, Michael and Rieger, Gotthard and Echlin, Mclean and Levi, Carlos and Pollock, Tresa} } @conference {1596, title = {3D Characterization of the Columnar-to-Equiaxed Transition in Additively Manufactured Inconel 718}, booktitle = {Superalloys 2020}, year = {2020}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {

Additive manufacturing (AM) provides enormous process- ing flexibility, enabling novel part geometries and opti- mized designs. Access to a local heat source further per- mits the potential for local microstructure control on the scale of individual melt pools, which can enable local con- trol of part properties. In order to design tailored process- ing strategies for target microstructures, models predict- ing the columnar-to-equiaxed transition must be extended to the high solidification velocities and complex thermal histories present in AM. Here, we combine 3D charac- terization with advanced modeling techniques to develop a more complete understanding of the solidification pro- cess and evolution of microstructure during electron beam melting (EBM) of Inconel 718. Full calibration of existing microstructure prediction models demonstrates the differ- ences between AM processes and more conventional weld- ing techniques, underlying the need for accurate deter- mination of key parameters that can only be measured directly in 3D. The ability to combine multisensor data in a consistent 3D framework via data fusion algorithms is essential to fully leverage these advanced characteriza- tion approaches. Thermal modeling provides insight on microstructure development within isolated solidification events and demonstrates the role of Marangoni effects on controlling solidification behavior.

}, keywords = {Additive manufacturing, Microstructure, Solidification, Tomography}, isbn = {9783030518349}, doi = {10.1007/978-3-030-51834-9}, url = {http://dx.doi.org/10.1007/978-3-030-51834-9_65}, author = {Polonsky, Andrew T. and Raghavan, Narendran and Echlin, Mclean P. and Kirka, Michael M. and Dehoff, Ryan R. and Pollock, Tresa M.}, editor = {Tin, Sammy and Hardy, Mark and Clews, Justin and Cormier, Jonathan and Feng, Qiang and Marcin, John and O{\textquoteright}Brien, Chris and Suzuki, Akane} } @article {1336, title = {Accelerated discovery of oxidation resistant CoNi-base γ/γ{\textquoteright} alloys with high L12 solvus and low density}, journal = {Materials and Design}, volume = {189}, year = {2020}, pages = {1{\textendash}12}, abstract = {

A systematic and accelerated methodology for alloy design is demonstrated by combining combinatorial synthesis, high-throughput oxide scale characterization, computational density functional theory, and CALPHAD database calculations. By applying this strategy to the senary Co-Ni-W-Al-Cr-Ta material system, a novel \γ/\γ\&$\#$39; alloy exhibiting a superior combination of properties has been identified. Properties include a \γ\&$\#$39; solvus near 1200 \°C, continuous \α-Al2O3 scale formation after 1 h in air at 1100 \°C, and comparable density to 2nd-generation commercial Ni-base superalloys. This novel alloy SB-CoNi-10 has a nominal composition of 39.8Co \– 36.5Ni \– 13.2Al \– 1.0W \– 6.0Cr \– 3.5Ta at.\%, and its properties are compared with other recently studied Co-, CoNi-, and Ni-base \γ/\γ\&$\#$39; alloys.

}, keywords = {Alloy design, Cobalt-base superalloys, Combinatorial synthesis, Oxidation, Superalloys}, issn = {18734197}, doi = {10.1016/j.matdes.2019.108445}, author = {Stewart, Colin A. and Murray, Sean P. and Suzuki, Akane and Pollock, Tresa M. and Levi, Carlos G.} } @inbook {1531, title = {Acquisition of 3D Data for Prediction of Monotonic and Cyclic Properties of Superalloys}, booktitle = {Integrated Computational Materials Engineering (ICME): Advancing Computational and Experimental Methods}, year = {2020}, pages = {1{\textendash}18}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {

The component design and fatigue life prediction of turbine disk alloys are critically dependent on the thermomechanical properties of the material. The TriBeam microscope provides a pathway to capture large, targeted 3D microstructural data volumes from turbine disk alloys in order to instantiate models that are used to simulate mechanical loading and assess material properties. The TriBeam experiments used to capture the microstructure, the analysis methods, data requirements, and future needs for 3D infrastructure will be discussed.

}, isbn = {978-3-030-40562-5}, doi = {10.1007/978-3-030-40562-5_1}, url = {https://doi.org/10.1007/978-3-030-40562-5_1}, author = {Echlin, Mclean P. and Lenthe, William C. and Stinville, Jean-Charles and Pollock, Tresa M.}, editor = {Ghosh, Somnath and Woodward, Christopher and Przybyla, Craig} } @article {1806, title = {Assessment of grain structure evolution with resonant ultrasound spectroscopy in additively manufactured nickel alloys}, journal = {Materials Characterization}, volume = {167}, year = {2020}, pages = {110501}, abstract = {

Despite the advantages of metal additive manufacturing (AM), ensuring integrity and reproducibility for built components is a barrier to the implementation of AM components in critical applications. Component qualification necessitates Non-Destructive Evaluation (NDE), but existing NDE frameworks are insufficient for the rapid and cost effective screening of variable AM components. In this study, alterations in laser powder bed fusion (LPBF) AM process parameters were characterized using resonant ultrasound spectroscopy (RUS). Samples that were subjected to a Hot Isostatic Press (HIP) and Heat Treatment (HT) post-processing step exhibited changes in resonance frequencies that varied in magnitude and direction with the type of resonance mode. The initial build direction prior to HIP and HT had a negligible effect on resonant frequency changes after recrystallization. The change in resonant frequencies at each process condition was predicted using Finite Element Modeling (FEM) informed with Electron Backscatter Diffraction (EBSD) data. FEM identified that the experimentally measured change in resonant response between the initially textured state and the recrystallized state was dominated by grain orientation dependent changes in elasticity. The EBSD-estimated elastic constants and FEM results were validated using experimental laser vibrometry and RUS inversion of elastic constants. RUS Inversion by Bayesian inference and Hamiltonian Monte Carlo has not been used to characterize an AM nickel-base alloy prior to this work. These results demonstrate that RUS is capable of detecting part to part microstructure variability between built AM components.

}, keywords = {Additive manufacturing, Bayesian inference, Elastic constant inversion, Finite element modeling, Recrystallization, Resonance ultrasound spectroscopy}, issn = {1044-5803}, doi = {https://doi.org/10.1016/j.matchar.2020.110501}, url = {https://www.sciencedirect.com/science/article/pii/S1044580320319720}, author = {Jeff Rossin and Brent Goodlet and Chris Torbet and William Musinski and Marie Cox and Jonathan Miller and Michael Groeber and Alexander Mayes and Eric Biedermann and Stephen Smith and Samantha Daly and Tresa Pollock} } @article {1416, title = {Automated and quantitative analysis of plastic strain localization via multi-modal data recombination}, journal = {Materials Characterization}, volume = {163}, year = {2020}, pages = {110245}, issn = {10445803}, doi = {10.1016/j.matchar.2020.110245}, url = {https://linkinghub.elsevier.com/retrieve/pii/S1044580319335569}, author = {Charpagne, M.A. and Stinville, J.C. and Callahan, P.G. and Texier, D. and Chen, Z. and Villechaise, P. and Valle, V. and Pollock, T.m.} } @article {1556, title = {Closing the science gap in 3D metal printing}, journal = {Science}, volume = {368}, year = {2020}, pages = {583{\textendash}584}, abstract = {

Additive manufacturing [three-dimensional (3D) printing] methodologies for high\–melting point metallic materials are being used in the advanced aerospace and biomedical sectors to fabricate high-value and geometrically complex parts in moderate production volumes. One barrier to more widespread applications is the gaps in the understanding of the processes that occur during the layer-by-layer buildup by beam heating and melting of powder or wire layers. For example, the absorption of energy in powder layers that are only a few particles thick is poorly understood. On page 660 of this issue, Khairallah et al. (1) used in situ x-ray synchrotron observations of powder dynamics coupled to thermal and hydrodynamic flow modeling to study energy absorption at the scale of powder particles. The presence of the powder, relative to a flat plate without powder, improves absorptivity at low laser power, but as power approaches 200 W, the details of the powder become far less important.

}, doi = {10.1126/science.abb4938}, author = {Polonsky, Andrew T. and Pollock, Tresa M.} } @conference {1611, title = {Creep, Fatigue, and Oxidation Interactions During High and Very High Cycle Fatigue at Elevated Temperature of Nickel-Based Single Crystal Superalloys}, booktitle = {Superalloys 2020}, year = {2020}, abstract = {

High-temperature fatigue of Ni-based single crystal superalloys is studied at 1000 \°C in a wide range of loading conditions (\−1 ? R ? 0.8) and number of cycles (103 \− 109). Under fully reversed conditions, a competition between crack initiations from the surface\— assisted by oxidation\—and from internal metallurgical defects\—mostly large casting pores\—is observed. Increasing the testing frequency shifts the competition to a higher number of cycles. Conversely, decreasing the casting pore size or coating the specimen promotes surface initiations. When a positive mean stress is added (R ? 0), a creep deformation/damage mechanism mainly controls fatigue life, despite fracture surfaces presenting a variety of initiation types. Fatigue life can be predicted by a simple creep law if the contribution of the alternating stress is considered. A linear damage summation method that considers pure fatigue and pure creep damage is used to predict the fatigue lives, and Haigh diagrams for different alloys are presented.

}, keywords = {Creep, fatigue, High temperature, Superalloy}, isbn = {9783030518349}, doi = {10.1007/978-3-030-51834-9}, url = {http://dx.doi.org/10.1007/978-3-030-51834-9_65}, author = {Cervellon, A. and Yi, J. Z. and Corpace, F. and Hervier, Z. and Rigney, J. and Wright, P. K. and Torbet, C. J. and Cormier, J. and Jones, J. W. and Pollock, T. M.}, editor = {Tin, Sammy and Hardy, Mark and Clews, Justin and Cormier, Jonathan and Feng, Qiang and Marcin, John and O{\textquoteright}Brien, Chris and Suzuki, Akane} } @article {1701, title = {Design and Tailoring of Alloys for Additive Manufacturing}, journal = {Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science}, volume = {51}, year = {2020}, pages = {6000{\textendash}6019}, abstract = {

Additive manufacturing (AM) promises a major transformation for manufacturing of metallic components for aerospace, medical, nuclear, and energy applications. This perspective paper addresses some of the opportunities for alloy and feedstock design to achieve site-specific and enhanced properties not attainable by conventional manufacturing processes. This paper provides a brief overview of the role of powders, as well as solidification and solid-state phase transformation phenomena typically encountered during fusion-based AM. Three case studies are discussed that leverage the above to arrive at microstructure control. The first case study focuses on approaches to modify the solidification characteristics by in-situ alloying. The second case study focuses on the need for concurrent design of alloys and processing conditions to arrive at the columnar to equiaxed transition during solidification. The third case study focuses on the design of a cobalt alloy for AM, with emphasis on tailoring liquid and solid state phase transformations. The need for comprehensive knowledge of processing conditions during AM, in-situ and ex-situ probing of microstructure development under AM conditions, and post-print processing, characterization, and qualification are articulated for the design of future alloys and component geometries built by AM.

}, issn = {10735623}, doi = {10.1007/s11661-020-06009-3}, url = {https://doi.org/10.1007/s11661-020-06009-3}, author = {Pollock, T. M. and Clarke, A. J. and Babu, S. S.} } @article {1571, title = {Design of Nickel-Cobalt-Ruthenium Multi-Principal Element Alloys}, journal = {Acta Materialia}, year = {2020}, pages = {16013}, keywords = {Alloy design, Density functional theory, High Entropy Alloys, planar fault energies, TRIP, TWIP}, issn = {1359-6454}, doi = {10.1016/j.actamat.2020.05.003}, url = {https://doi.org/10.1016/j.actamat.2020.05.003}, author = {Charpagne, M A and Vamsi, K V and Eggeler, Y M and Murray, S P and Frey, C and Kolli, S K and Pollock, T M} } @article {1411, title = {Direct measurements of slip irreversibility in a nickel-based superalloy using high resolution digital image correlation}, journal = {Acta Materialia}, volume = {186}, year = {2020}, pages = {172{\textendash}189}, abstract = {

Fatigue crack nucleation in crystalline materials typically develops due to highly localized cyclic slip. During a fatigue cycle, reverse slip differs locally from slip in the forward direction particularly in precipitate-containing materials such as superalloys. In this paper we report the first direct measurements of irreversibility at the scale of individual slip bands by high-resolution digital image correlation (DIC) in a polycrystalline nickel-based superalloy. Quantitative measurements of the slip irreversibility are challenging for regions of material that have a size that captures the microstructure and its variability. High spatial resolution at the nanometer scale during experimental measurements is needed to observe slip localization during deformation. Moreover, large fields are also needed to obtain the material response over statistically representative populations of microstructural configurations. Recently, high resolution scanning electron microscope (SEM) digital image correlation (DIC) has been extended for quantitative analysis of discontinuities induced by slip events using the Heaviside-DIC method. This novel method provides quantitative measurements of slip localization at the specimen surface. In this paper, the Heaviside-DIC method is used to measure slip irreversibility and plastic strain accumulation in a nickel-based superalloy. The method detects bands with high levels of irreversibility early in cycling that ultimately form fatigue cracks upon further cycling. The local microstructural configurations that induce large amounts of plasticity and slip irreversibility are correlated to crack nucleation locations.

}, keywords = {Heaviside-digital image correlation, High resolution digital image correlation, Low cycle fatigue, Polycrystalline Ren{\'e} 88DT nickel-based superalloy, Scanning electron microscopy digital image correlation, Slip irreversibility, Strain localization and accumulation}, issn = {13596454}, doi = {10.1016/j.actamat.2019.12.009}, url = {https://doi.org/10.1016/j.actamat.2019.12.009}, author = {Stinville, J. C. and Callahan, P. G. and Charpagne, M. A. and Echlin, M. P. and Valle, V. and Pollock, T. M.} } @article {1651, title = {Expanded dataset of mechanical properties and observed phases of multi-principal element alloys}, journal = {Scientific Data}, volume = {7}, year = {2020}, pages = {1{\textendash}6}, abstract = {

This data article presents a compilation of mechanical properties of 630 multi-principal element alloys\ (MPEAs). Built upon recently published MPEA databases, this article includes updated records from previous reviews (with minor error corrections) along with new data from articles that were published since 2019. The extracted properties include reported composition, processing method, microstructure, density, hardness, yield strength, ultimate tensile strength (or maximum compression strength), elongation (or maximum compression strain), and Young\&$\#$39;s modulus. Additionally, descriptors (e.g. grain size) not included in previous reviews were also extracted for articles that reported them. The database is hosted and continually updated on an open data platform, Citrination. To promote interpretation, some data are graphically presented.

}, issn = {20524463}, doi = {10.1038/s41597-020-00768-9}, author = {Borg, Christopher K.H. and Frey, Carolina and Moh, Jasper and Pollock, Tresa M. and Gorsse, St{\'e}phane and Miracle, Daniel B. and Senkov, Oleg N. and Meredig, Bryce and Saal, James E.} } @article {1696, title = {Grain refinement mechanisms in additively manufactured nano-functionalized aluminum}, journal = {Acta Materialia}, volume = {200}, year = {2020}, pages = {1022{\textendash}1037}, abstract = {

Additive manufacturing (AM) is a new and promising production methodology adept at producing complex geometries, which can be optimized for lower weight and enhanced capabilities. The material properties of these additive components are dictated by the microstructures developed during processing, with a high sensitivity to grain structure and associated anisotropy. With this new processing modality comes the added difficulty of understanding the thermodynamics and kinetic mechanisms that dictate the evolution of microstructure. This research addresses the unique thermal conditions present in AM and the pathways for grain refinement in nanofunctionalized aluminum alloys. The Al-Ta system, in which Al3Ta intermetallic compounds are demonstrated to have substantial grain refining capacity, are the focus of this study. The grain size is shown to be reduced relative to pure aluminum by 1000X when tantalum is added at 1 vol\%. The effectiveness of the Al3Ta intermetallic is dictated by the crystallography and availability of the inoculant phase under AM conditions.

}, keywords = {Additive manufacturing, Crystallography, Grain refinement, Nucleation, Solidification}, issn = {13596454}, doi = {10.1016/j.actamat.2020.09.043}, url = {https://doi.org/10.1016/j.actamat.2020.09.043}, author = {Martin, J. Hunter and Yahata, Brennan and Mayer, Justin and Mone, Robert and Stonkevitch, Ekaterina and Miller, Julie and O{\textquoteright}Masta, Mark R. and Schaedler, Tobias and Hundley, Jacob and Callahan, Patrick and Pollock, Tresa} } @article {1576, title = {Growth accidents induced by primary γ{\textquoteright} precipitates in a polycrystalline nickel-based superalloy}, journal = {Scripta Materialia}, volume = {186}, year = {2020}, pages = {1{\textendash}5}, keywords = {3D EBSD, Annealing twin boundaries, Critical recrystallization, Nickel-base superalloy, Recrystallization}, issn = {1359-6462}, doi = {10.1016/j.scriptamat.2020.05.020}, url = {https://doi.org/10.1016/j.scriptamat.2020.05.020}, author = {Charpagne, M A and Polonsky, A T and Echlin, M P and Jacomet, S and De Jaeger, J and De Graef, M and Bozzolo, N and Pollock, T M} } @article {1631, title = {Growth accidents induced by primary γ' precipitates in a polycrystalline nickel-based superalloy}, journal = {Scripta Materialia}, volume = {186}, year = {2020}, month = {09/2020}, pages = {109-113}, abstract = {

The development of overgrown grains during sub-solvus annealing of a polycrystalline\ \γ\−\γ\′\ nickel-base alloy is investigated, with special emphasis on the primary\ \γ\′ precipitates. Quantitative analysis conducted on a large three-dimensional electron back-scattered diffraction dataset reveals a high fraction of\ \γ\′ precipitates on the annealing twin boundaries in the large grains. When observed in-situ in a scanning electron microscope, the formation of annealing twins is correlated to the crossing of\ \γ\′ precipitates by moving grain boundaries. The role of precipitates in the occurrence of growth accidents is discussed.

}, keywords = {3D EBSD, Annealing twin boundaries, Critical recrystallization, Nickel-base superalloy, Recrystallization}, doi = {https://doi.org/10.1016/j.scriptamat.2020.05.020}, url = {https://www.sciencedirect.com/science/article/abs/pii/S1359646220302979$\#$fig0005}, author = {M.A. Charpagne and A.T. Polonsky and M.P. Echlin and S. Jacomet and J. de Jaeger and M. De Graef and N. Bozzolo and T.M. Pollock} } @article {1341, title = {Low Cycle Fatigue of Single Crystal γ'-containing Co-based Superalloys at 750 {\textdegree}C}, journal = {Metallurgical and Materials Transactions A}, volume = {51}, year = {2020}, pages = {200{\textendash}213}, abstract = {

A new class of \γ\′-containing Co-based superalloys that are promising for high temperature applications has been investigated under cyclic loading conditions. A series of single crystal variants of these Co-based superalloys have been cyclically loaded above their elastic limit at 750 \°C in air to study their behavior in the low cycle regime. Interrupted testing was performed to observe the early stages of fatigue failure. Optical microscopy, scanning electron microscopy, and transmission electron microscopy were used to characterize post-mortem specimens. Fatigue failure occurred due to surface cracks that developed during the early stages of cycling in the aluminide-coated sample gauge sections. Growth of these surface cracks into the substrate was associated with extensive oxidation and intermetallic phase precipitation, which accelerated crack propagation as compared to Ni-based superalloys. These observations suggest that improvements in the oxidation resistance and high temperature strength of \γ\′-containing Co-based superalloys will enhance their fatigue behavior.

}, issn = {1543-1940}, doi = {10.1007/s11661-019-05508-2}, url = {https://doi.org/10.1007/s11661-019-05508-2}, author = {Murray, Sean P and Stinville, Jean-Charles and Callahan, Patrick G and Rhein, Robert K and Pollock, Tresa M} } @article {1626, title = {Measurement of elastic and rotation fields during irreversible deformation using Heaviside-digital image correlation}, journal = {Materials Characterization}, volume = {169}, year = {2020}, month = {11/2020}, pages = {110600}, abstract = {

The recent development of the high resolution and discontinuity-tolerant digital image correlation technique enables the extraction of discontinuities within a displacement field. The technique provides quantitative analysis of discontinuities arising from slip, shear bands, cracks, and grain boundary sliding in a variety of material systems, including polycrystalline metallic materials. The discontinuity-tolerant digital image correlation method can be implemented to retrieve not only quantitative discontinuity analysis but also the local strain and rotation fields that operate near these discontinuities. The present implementation includes high-resolution digital image correlation (HR-DIC) measurements collected in a scanning electron microscope for analysis of both the plastic and elastic fields that develop during deformation of polycrystalline metallic materials. The combination of the discontinuity-tolerant DIC technique with the computation of internal gradients enables extraction of non-localized strain and rotation fields during plastic deformation of a nickel-based superalloy. Therefore the lattice rotation/expansion and plastic localization that occur during deformation can be determined in a single experiment. This method is validated using synthetic images with preset deformation, and experimental measurements using the electron back scatter diffraction (EBSD) technique.

}, doi = {https://doi.org/10.1016/j.matchar.2020.110600}, url = {https://www.sciencedirect.com/science/article/abs/pii/S1044580320320714}, author = {J.C. Stinville and M.A. Charpagne and F. Bourdin and P.G. Callahan and Z. Chen and M.P. Echlin and D. Texier and J. Cormier and P. Villechaise and T.M. Pollock and V. Valle} } @article {1581, title = {Microscale characterization of damage accumulation in CMCs}, journal = {Journal of the European Ceramic Society}, year = {2020}, abstract = {

The developing roles of damage mechanisms in the failure response of SiC/SiC minicomposites was investigated by the characterization of microscale damage accumulation with respect to microstructure. A multi-modal approach combining spatially resolved acoustic emission (AE) with tensile testing in-SEM (scanning electron microscope) was used to simultaneously examine surface (observed in-SEM) and bulk damage (monitored via AE). Strong agreement was shown between the evolving crack density estimated by AE and in-SEM measurements. The following were observed: (i) in-plane matrix content and distribution impacted crack growth; (ii) spatially-distributed matrix cracks generated varying stress-dependent AE; and (iii) certain individual cracks became more probable failure locations due to unique combinations of damage mechanisms that drove their growth. This approach enabled characterizing potential failure determinants and suggests that early damage behavior is related to certain microstructural features (e.g. surface flaws), while subsequent damage behavior is coupled to interactions of local mechanisms evolving with stress.

}, keywords = {Acoustic emission, Ceramic matrix composite, Cracking, Damage initiation, Silicon carbide}, issn = {1873619X}, doi = {10.1016/j.jeurceramsoc.2020.05.077}, url = {https://doi.org/10.1016/j.jeurceramsoc.2020.05.077}, author = {Swaminathan, B. and McCarthy, N. R. and Almansour, A. S. and Sevener, K. and Pollock, T. M. and Kiser, J. D. and Daly, S.} } @conference {1591, title = {Microstructure and Tensile Properties of a CoNi-Based Superalloy Fabricated by Selective Electron Beam Melting}, booktitle = {Superalloys 2020}, year = {2020}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {

Successful application of selective electron beam melting to a novel CoNi-based superalloy named SB-CoNi-10 is demonstrated. Crack-free as-printed microstructures exhibit excellent ductilities above 30\% and ultimate tensile strengths above 1.1 GPa at room temperature in tension. Conventional post-processing consisting of a super-solvus hot isostatic pressing (HIP), a solution heat treatment (SHT), and a low-temperature aging has been applied to remove microstructural inhomogeneities present in the as-printed microstructure. The microstructures of the as-printed and HIP+SHT+Aged alloys have been investigated to determine the effect of post-processing heat treatments on the nanoscale \γ/\γ\&$\#$39; microstructure and the mesoscale grain structure. Tensile tests have been conducted at room temperature and elevated temperatures above 850 {\textopenbullet}C to investigate mechanical properties in both the as-printed and HIP+SHT+Aged conditions. The high- temperature ductility and strength are strongly affected by the microstructure, with a mostly columnar-grained microstructure in the as-printed condition exhibiting superior ductility to the fully recrystallized microstructure in the HIP+SHT+Aged condition.

}, keywords = {Additive manufacturing, CoNi-based superalloys, Mechanical properties}, isbn = {9783030518349}, doi = {10.1007/978-3-030-51834-9}, url = {http://dx.doi.org/10.1007/978-3-030-51834-9_65}, author = {Murray, Sean P. and Pusch, Kira M. and Polonsky, Andrew T. and Torbet, Chris J. and Seward, Gareth G. E. and Nandwana, Peeyush and Kirka, Michael M. and Dehoff, Ryan R. and Zhou, Ning and Forsik, St{\'e}phane A. J. and Slye, William and Pollock, Tresa M.}, editor = {Tin, Sammy and Hardy, Mark and Clews, Justin and Cormier, Jonathan and Feng, Qiang and Marcin, John and O{\textquoteright}Brien, Chris and Suzuki, Akane} } @article {1691, title = {Multiplicity of dislocation pathways in a refractory multiprincipal element alloy}, journal = {Science}, volume = {370}, year = {2020}, pages = {95{\textendash}101}, abstract = {

Refractory multiprincipal element alloys (MPEAs) are promising materials to meet the demands of aggressive structural applications, yet require fundamentally different avenues for accommodating plastic deformation in the body-centered cubic (bcc) variants of these alloys. We show a desirable combination of homogeneous plastic deformability and strength in the bcc MPEA MoNbTi, enabled by the rugged atomic environment through which dislocations must navigate. Our observations of dislocation motion and atomistic calculations unveil the unexpected dominance of nonscrew character dislocations and numerous slip planes for dislocation glide. This behavior lends credence to theories that explain the exceptional high temperature strength of similar alloys. Our results advance a defect-aware perspective to alloy design strategies for materials capable of performance across the temperature spectrum.

}, issn = {10959203}, doi = {10.1126/science.aba3722}, author = {Wang, Fulin and Balbus, Glenn H. and Xu, Shuozhi and Su, Yanqing and Shin, Jungho and Rottmann, Paul F. and Knipling, Keith E. and Stinville, Jean Charles and Mills, Leah H. and Senkov, Oleg N. and Beyerlein, Irene J. and Pollock, Tresa M. and Gianola, Daniel S.} } @inbook {1536, title = {Multi-scale Microstructure and Property-Based Statistically Equivalent RVEs for Modeling Nickel-Based Superalloys}, booktitle = {Integrated Computational Materials Engineering (ICME): Advancing Computational and Experimental Methods}, year = {2020}, pages = {55{\textendash}90}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {

This chapter discusses fundamental aspects of the development of statistically equivalent virtual microstructures (SEVMs) and microstructure and property-based statistically equivalent representative volume elements (M-SERVE and P-SERVE) of the Ni-based superalloy at multiple scales. The two specific scales considered for this development are the subgrain scale of intragranular \γ\thinspace\−\thinspace\γ\textasciiacutex microstructures and the polycrystalline scale of grain ensembles with annealing twins. A comprehensive suite of computational methods that can translate microstructural data in experimental methods to optimally defined representative volumes for effective micromechanical modeling is the objective of this study. The framework involves a sequence of tasks, viz., serial sectioning, image processing, feature extraction, and statistical characterization, followed by micromechanical analysis and convergence tests for statistical functions. A principal motivation behind this paper is to translate high-fidelity microstructural image data into statistics of parametric descriptors in constitutive laws governing material performance.

}, isbn = {978-3-030-40562-5}, doi = {10.1007/978-3-030-40562-5_3}, url = {https://doi.org/10.1007/978-3-030-40562-5_3}, author = {Ghosh, Somnath and Weber, George and Pinz, Maxwell and Bagri, Akbar and Pollock, Tresa M. and Lenthe, Will and Stinville, Jean-Charles and Uchic, Michael D. and Woodward, Christopher}, editor = {Ghosh, Somnath and Woodward, Christopher and Przybyla, Craig} } @article {1331, title = {A new proximate structure for the APB (111) in L12 compounds}, journal = {Scripta Materialia}, volume = {182}, year = {2020}, pages = {38{\textendash}42}, abstract = {

A new approach which involves a diffuse multi-layer fault model coupled with a cluster approach to statistical mechanics (CASM) infrastructure has been developed to identify the proximate structure for the antiphase boundary (APB) on {111} planes in L12. We report a new structure, \‘\γa\′\&$\#$39; which approximates the bonding environment of an APB better than a previously reported structure, \‘\ω\&$\#$39;. Density functional theory calculations were employed to predict the APB energies from structural energies of \γa\′ and L12 and were validated against estimations from supercell methods for several binary compounds. The implications of the discovery of the \γa\′ are discussed.

}, keywords = {Antiphase boundaries, Density functional theory, High-throughput calculations, Planar faults energies, Superalloys}, issn = {13596462}, doi = {10.1016/j.scriptamat.2020.02.038}, url = {https://doi.org/10.1016/j.scriptamat.2020.02.038}, author = {Vamsi, K. V. and Pollock, Tresa M.} } @article {1526, title = {Non-destructive evaluation of 3D microstructure evolution in strontium titanate}, journal = {Journal of Applied Crystallography}, volume = {53}, year = {2020}, pages = {1{\textendash}11}, abstract = {

Nondestructive X-ray diffraction contrast tomography imaging was used to characterize the microstructure evolution in a polycrystalline bulk strontium titanate specimen. Simultaneous acquisition of diffraction and absorption information allows for the reconstruction of shape and orientation of more than 800 grains in the specimen as well as porosity. Three-dimensional microstructure reconstructions of two coarsening states of the same specimen are presented alongside a detailed exploration of the crystallographic, topological and morphological characteristics of the evolving microstructure. The overall analysis of the 3D structure shows a clear signature of the grain boundary anisotropy, which can be correlated to surface energy anisotropy: the grain boundary plane distribution function shows an excess of {\textlangle}100{\textrangle}-oriented interfaces with respect to a random structure. The results are discussed in the context of interface property anisotropy effects.

}, keywords = {3d materials, contrast tomography, diffraction, grain growth, microstructure evolution, nondestructive x-ray diffraction contrast, science, strontium titanate, to, tomography imaging was used}, doi = {10.1107/S160057672000093X}, author = {Trenkle, Andreas and Syha, Melanie and Rheinheimer, Wolfgang and Callahan, Patrick and Nhuyen, Lily and Ludwig, Wolfgang and Lenthe, William and Echlin, Mclean and Pollock, Tresa and Weygand, Daniel and Hoffmann, Michael and Gumbsch, Peter} } @conference {1606, title = {Role of Non-metallic Inclusions and Twins on the Variability in Fatigue Life in Alloy 718 Nickel Base Superalloy}, booktitle = {Superalloys 2020}, year = {2020}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {

Non-metallic inclusions (NMIs) and slip bands parallel to and slightly offset from twin boundaries are observed to be preferential sites for fatigue crack nucleation in wrought superalloys. Potential interactions between NMI cracking and slip activity within neighboring grains or at twin boundaries were investigated under monotonic tensile loading (up to 1.3\% total strain) at room temper- ature. High resolution- and Heaviside-digital image correlation measurements were performed during inter- rupted tensile loading to identify strain localization, associated slip systems, and damage initiation. Different mechanisms and scenarios were identified: (1) Microplas- ticity generally starts at twin boundaries even at stresses as low as 70\% of the macroscopic yield strength, (2) transgranular slip activity intensively develops above the macroscopic yield stress, (3) intense slip activity develops near and parallel to 21\% of the twin boundaries intercepting NMIs, (4) 7\% of the twin boundaries inter- cepting NMIs lead to slip-assisted NMI cracking, (5) no transgranular slip activity participates in NMI cracking, (6) the fraction of cracked NMIs progressively increases with the load, and (7) within the NMIs that initiated cracks, 67\% cracked below 90\% of the macroscopic yield strength without the presence of slip activity in the neighboring grains. While slip-assisted NMI cracking was evidenced in the present study, most NMI cracking is due to strain incompatibility between NMIs and neighboring grains at the high end of the elastic regime without slip interaction.

}, keywords = {fatigue, High Resolution-Digital Image Correlation (HR-DIC), In-situ tensile testing, Non-metallic inclusions (NMIs), Twin boundary}, isbn = {9783030518349}, doi = {10.1007/978-3-030-51834-9}, url = {http://dx.doi.org/10.1007/978-3-030-51834-9_65}, author = {Texier, Damien and Stinville, Jean-Charles and Charpagne, Marie-agathe and Chen, Zhe and Valle, Valery and Villechaise, Patrick and Pollock, Tresa M. and Cormier, Jonathan}, editor = {Tin, Sammy and Hardy, Mark and Clews, Justin and Cormier, Jonathan and Feng, Qiang and Marcin, John and O{\textquoteright}Brien, Chris and Suzuki, Akane} } @article {1566, title = {Serial sectioning in the SEM for three dimensional materials science}, journal = {Current Opinion in Solid State and Materials Science}, year = {2020}, pages = {100817}, abstract = {

Here we explore the range of serial sectioning techniques that have evolved over the past decade, providing a comprehensive toolkit for capturing rich 3D microstructures, chemistries and crystallographic information, with sub-micron resolution at volumes that extend out to mm3 or even cm3. In each case we consider the challenges associated with their application, the volumes they can analyze, the damage to the surface they impart, and their suitability for different materials. In certain cases these warrant hybrid methods, motivating workflows that leverage multiple sectioning modes within the same instrument. Finally, we provide a perspective on their future development, including advances in data collection, segmentation, registration, data fusion, and correlative microscopy. Furthermore, the exploitation of 3D techniques for a better understanding of existing materials, and the design of new ones, is discussed through their use in multiscale modelling, digital twinning, material informatics and machine learning frameworks.

}, keywords = {Biology, Life sciences, Materials science, Scanning electron microscopy, Serial sectioning}, issn = {13590286}, doi = {10.1016/j.cossms.2020.100817}, url = {https://doi.org/10.1016/j.cossms.2020.100817}, author = {Echlin, Mclean P. and Burnett, Timothy L. and Polonsky, Andrew T. and Pollock, Tresa M. and Withers, Philip J.} } @article {1406, title = {Solidification-driven orientation gradients in additively manufactured stainless steel}, journal = {Acta Materialia}, volume = {183}, year = {2020}, pages = {249{\textendash}260}, abstract = {

A sample of 304L stainless steel manufactured by Laser Engineered Net Shaping (LENS) was characterized in 3D using TriBeam tomography. The crystallographic, structural, and chemical properties of the as-deposited microstructure have been studied in detail. 3D characterization reveals complex grain morphologies and large orientation gradients, in excess of 10o, that are not easily interpreted from 2D cross-sections alone. Misorientations were calculated via a methodology that locates the initial location and orientation of grains that grow during the build process. For larger grains, misorientation increased along the direction of solidification. For grains with complex morphologies, K-means clustering in orientation space is demonstrated as a useful approach for determining the initial growth orientation. The gradients in misorientation directly tracked with gradients in chemistry predicted by a Scheil analysis. The accumulation of misorientation is linked to the solutal and thermal solidification path, offering potential design pathways for novel alloys more suited for additive manufacturing.

}, keywords = {Additive manufacturing, Microstructure, Solidification, Tomography, Tribeam}, issn = {13596454}, doi = {10.1016/j.actamat.2019.10.047}, author = {Polonsky, Andrew T. and Lenthe, William C. and Echlin, Mclean P. and Livescu, Veronica and Gray, George T. and Pollock, Tresa M.} } @article {1561, title = {Structural coupling and magnetic tuning in Mn$_{2}$$_{-}$ₓCoₓP magnetocalorics for thermomagnetic power generation}, journal = {APL Materials}, volume = {8}, year = {2020}, pages = {041106}, abstract = {

Promising materials for magnetic refrigeration and thermomagnetic power generation often display strong coupling between magnetism and structure. It has been previously proposed that MnCoP exhibits this strong coupling, contributing to its substantial magnetocaloric effect near TC = 578K. Here, we show from temperature-dependent synchrotron x-ray diffraction that MnCoP displays a discontinuity in the thermal expansion at TC, with spontaneous magnetostriction that is positive in the a direction and negative in the b direction, highlighting the anisotropic nature of the magnetostructural coupling. Varying the Mn:Co ratio of Mn2-xCoxP within the range of 0.6 \≤ x \≤ 1.4 allows the magnetic properties to be tuned. TC decreases as the composition deviates from stoichiometric MnCoP, as does the saturation magnetization. The magnitude of the magnetocaloric effect, |\ΔSM|, decreases as well, due to broadening of the magnetic transition. The large reversible change in magnetization \ΔM accessible over a small temperature range under moderate magnetic fields makes these materials promising for thermomagnetic power generation from waste heat.

}, issn = {2166532X}, doi = {10.1063/1.5142000}, url = {https://doi.org/10.1063/1.5142000}, author = {Levin, Emily E. and Bocarsly, Joshua D. and Grebenkemper, Jason H. and Issa, Ramsey and Wilson, Stephen D. and Pollock, Tresa M. and Seshadri, Ram} } @article {1621, title = {Sustainability through alloy design: Challenges and opportunities}, journal = {Progress in Materials Science}, year = {2020}, pages = {100722}, abstract = {

Exciting metallurgical breakthroughs of the last decades alongside the development and wide-ranging availability of new and more capable experimental and theoretical tools for metals research demonstrate that we are witnessing the dawn of a new age in metals design. Historically, the discovery of new metallic materials has enabled the vast majority of the key engineering advances in human history. Current engineering challenges create an urgent need for new metallic materials to further our technological advances in multiple industries that are key to our existence. Yet, present data on metals processing clearly demonstrate the significant environmental impact of the metallurgical industry on our planet\&$\#$39;s future. There are numerous reports in which this impact and corresponding processing solutions are discussed. On the other hand, design of new metallic materials with improved property combinations can help address key environmental challenges in various ways. To this end, the goal of this review is to discuss the most urgent sustainability challenges that can be addressed with alloy design, to help orchestrate the increasing interest in metallurgical research to focus on these most critical challenges.

}, keywords = {Aluminum, High Entropy Alloys, Magnesium, Metallurgy, Shape memory alloys, Steel, Superalloys, Sustainability, Titanium}, issn = {00796425}, doi = {10.1016/j.pmatsci.2020.100722}, url = {https://doi.org/10.1016/j.pmatsci.2020.100722}, author = {Cann, Jaclyn L. and De Luca, Anthony and Dunand, David C. and Dye, David and Miracle, Daniel B. and Oh, Hyun Seok and Olivetti, Elsa A. and Pollock, Tresa M. and Poole, Warren J. and Yang, Rui and Tasan, C. Cem} } @article {1401, title = {Three-dimensional maps of geometrically necessary dislocation densities in additively manufactured Ni-based superalloy IN718}, journal = {International Journal of Plasticity}, year = {2020}, pages = {102709}, keywords = {Dislocations, Metallic material, Microstructures, Polycrystalline material, Three-dimensional electron backscatter diffraction}, issn = {0749-6419}, doi = {10.1016/j.ijplas.2020.102709}, url = {https://doi.org/10.1016/j.ijplas.2020.102709}, author = {Witzen, Wyatt A. and Polonsky, Andrew T. and Pollock, Tresa M. and Beyerlein, Irene J.} } @conference {1616, title = {Tuning Strain Localization in Polycrystalline Nickel-Based Superalloys by Thermomechanical Processing}, booktitle = {Superalloys 2020}, year = {2020}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {

Thermomechanical processing routes are used to produce microstructures that minimize plastic strain localization at the sub-grain scale in a polycrystalline \γ \− \γ\&$\#$39; nickel- based superalloy. This novel approach is made possible by the use of innovative experimental tools and statistical data analysis that capture slip events over large represen- tative fields of view. Results are correlated to conventional observations of fatigue crack initiation and early stage of propagation. The effect of coherent twin boundaries and primary \γ\&$\#$39; precipitates on fatigue properties and plastic localization is detailed.

}, keywords = {3D microstructure, Annealing twin boundaries, Nickel-based superalloy, Primary γ{\textquoteright} precipitates, Slip bands}, isbn = {9783030518349}, doi = {10.1007/978-3-030-51834-9}, url = {http://dx.doi.org/10.1007/978-3-030-51834-9_65}, author = {Charpagne, M. A. and Stinville, J. C. and Polonsky, A. T. and Echlin, M. P. and Murray, S. P. and Chen, Z. and Bozzolo, N. and Cormier, J. and Valle, V. and Pollock, T. M.}, editor = {Tin, Sammy and Hardy, Mark and Clews, Justin and Cormier, Jonathan and Feng, Qiang and Marcin, John and O{\textquoteright}Brien, Chris and Suzuki, Akane} } @article {1586, title = {Twin related domain networks in Ren{\'e} 88DT}, journal = {Materials Characterization}, volume = {165}, year = {2020}, pages = {110365}, abstract = {

Annealing twins in wrought fcc materials have historically been characterized using simple 2D measures including morphology and volume fraction. Accurately describing twin related domain microstructure requires accounting for their complex 3D structure. A large microstructural volume of a nickel-base alloy Ren\é 88DT has been collected using TriBeam tomography for full characterization of a large number of complete twin related domains. A network based approach enables visualization of twin domain structures. Metrics adapted from graph theory enable the first quantitative 3D microstructure descriptions. The implications for fatigue properties in twinned nickel-base alloys are discussed.

}, keywords = {3D EBSD, Annealing twin boundaries, Graph theory, Nickel-base superalloy, Recrystallization, Tribeam, Twins}, issn = {10445803}, doi = {10.1016/j.matchar.2020.110365}, url = {https://doi.org/10.1016/j.matchar.2020.110365}, author = {Lenthe, William C. and Echlin, Mclean P. and Stinville, Jean C. and De Graef, Marc and Pollock, Tresa M.} } @conference {1601, title = {The Yield Strength Anomaly in Co-Ni Design Space}, booktitle = {Superalloys 2020}, year = {2020}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {

A new computational approach to model precipitate compositions and properties in the CoNi-design space for yield strength anomaly prediction is presented. The antiphase boundary (APB) energies on {111} and {010} and the degree of elastic anisotropy are known to influence the yield strength anomaly. APB energies were estimated by a diffuse multi-layer fault (DMLF) model using the structural energies of proximate structures: L12, ca\′, and D023. The elastic moduli were calculated via the energy-strain approach using density functional theory calculations. (Ni1\−xCox)3(Al1\−yWy) was chosen as the model system, and Yoo\&$\#$39;s criterion is evaluated over the entire range ofcompositions to identify regions that exhibit the yield strength anomaly. (Ni0.65Co0.35)3(Al0.5W0.5) has the maximum APB (111) and any two-phase alloy (c + c') in Ni\–Co\–Al\–W system with this precipitate composition might exhibit higher strength upon shearing by a matrix dislocation. ThermoCalc was employed to identify stable L12 regions in (Ni1\−xCox)3(Al1\−yWy). The effect of Co on the yield strength anomaly was investigated experimen- tally in three (Ni1\−xCox)3Al alloys with L12 structure. All three alloys exhibited the yield strength anomaly, validat- ing the computational approach. The addition of Co provides solid solution strengthening to Ni3Al at room temperature; however, this contribution to the overall strength diminished as a function of temperature. CoNi-alloys displayed strengths similar to Ni3Al at elevated temperatures with Co addition resulting in a marginal increase in strength at the peak temperature. The present study elucidates that APB energies from a DMLF model combined with elastic moduli can be employed to predict yield strength anomaly using Yoo\&$\#$39;s criteria.

}, keywords = {Antiphase boundaries, CoNi-based superalloys, Yield strength anomaly}, isbn = {9783030518349}, doi = {10.1007/978-3-030-51834-9}, url = {http://dx.doi.org/10.1007/978-3-030-51834-9_65}, author = {Vamsi, K. V. and Murray, Sean P. and Pollock, Tresa M.}, editor = {Tin, Sammy and Hardy, Mark and Clews, Justin and Cormier, Jonathan and Feng, Qiang and Marcin, John and O{\textquoteright}Brien, Chris and Suzuki, Akane} } @article {1511, title = {A 3D analysis of the onset of slip activity in relation to the degree of micro-texture in Ti{\textendash}6Al{\textendash}4V}, journal = {Acta Materialia}, volume = {181}, year = {2019}, pages = {36{\textendash}48}, abstract = {

The mechanical properties of titanium alloys result from their complex multi-scale microstructural features, including micron scale precipitates and millimeter scale microtextured regions (MTRs). While previous investigations have revealed that the presence of mm-scale MTRs can degrade mechanical properties, particularly fatigue, the accompanying strain localization processes that operate at the microscale within the \α grains in MTRs are not well understood. The present work is a mechanistic investigation of MTRs using crystal plasticity simulations of mm3-scale experimentally captured and synthetically generated 3D microstructure datasets. The explicit modeling of both the \α grains and MTRs in Ti\–6Al\–4V enables assessment of the effect of microtexture and local structure variations within the MTR on overall deformation behavior and the onset of plastic slip in MTRs. The presence of MTRs with a dominant [0001] orientation results in both stress and plastic strain hotspots during the early stages of straining. Crystal plasticity predictions are compared to previous digital image correlation studies on early strain localization. The influence of MTRs on the local stress and strain fields is discussed with regard to the monotonic tension, fatigue and dwell-fatigue behavior of titanium alloys.

}, keywords = {3D EBSD, Crystal plasticity, Macrozones, Microtexture, Titanium alloys}, issn = {13596454}, doi = {10.1016/j.actamat.2019.09.028}, url = {https://doi.org/10.1016/j.actamat.2019.09.028}, author = {H{\'e}mery, S. and Na{\"\i}t-Ali, A. and Gu{\'e}guen, M. and Wendorf, J. and Polonsky, A. T. and Echlin, M. P. and Stinville, J. C. and Pollock, T. M. and Villechaise, P.} } @article {1366, title = {Accurate reconstruction of EBSD datasets by a multimodal data approach using an evolutionary algorithm}, journal = {Materials Characterization}, volume = {150}, year = {2019}, pages = {184{\textendash}198}, abstract = {

A new method has been developed for the correction of the distortions and/or enhanced phase differentiation in Electron Backscatter Diffraction (EBSD) data. Using a multi-modal data approach, the method uses segmented images of the phase of interest (laths, precipitates, voids, inclusions) on images gathered by backscattered or secondary electrons of the same area as the EBSD map. The proposed approach then searches for the best transformation to correct their relative distortions and recombines the data in a new EBSD file. Speckles of the features of interest are first segmented in both the EBSD and image data modes. The speckle extracted from the EBSD data is then meshed, and the Covariance Matrix Adaptation Evolution Strategy (CMA-ES) is implemented to distort the mesh until the speckles superimpose. The quality of the matching is quantified via a score that is linked to the number of overlapping pixels in the speckles. The locations of the points of the distorted mesh are compared to those of the initial positions to create pairs of matching points that are used to calculate the polynomial function that describes the distortion the best. This function is then applied to un-distort the EBSD data, and the phase information is inferred using the data of the segmented speckle. Fast and versatile, this method does not require any human annotation and can be applied to large datasets and wide areas. Besides, this method requires very few assumptions concerning the shape of the distortion function. It can be used for the single compensation of the distortions or combined with the phase differentiation. The accuracy of this method is of the order of the pixel size. Some application examples in multiphase materials with feature sizes down to 1 \μm are presented, including Ti-6Al-4 V Titanium alloy, Rene 65 and additive manufactured Inconel 718 Nickel-base superalloys.

}, keywords = {CMA-ES, Distortions, EBSD, Image segmentation, Multi-modal data}, issn = {10445803}, doi = {10.1016/j.matchar.2019.01.033}, url = {https://doi.org/10.1016/j.matchar.2019.01.033}, author = {Charpagne, Marie Agathe and Strub, Florian and Pollock, Tresa M.} } @article {1506, title = {Alloy Design and Processing Design of Magnesium Alloys Using 2nd Phases}, journal = {JOM}, volume = {71}, year = {2019}, pages = {2219{\textendash}2226}, abstract = {

Two phases dominate the performance of commercial Mg alloys: (1) \β Mg17Al12 and (2) porosity. Alloy design and process design to optimize the morphology of the first and to minimize the second are discussed. Second phase \β can be designed to improve tensile strength, fatigue strength, toughness, texture, formability and corrosion resistance of Mg alloys. Processing is applied to refine the grain size, to array this phase in micron sizes at grain boundaries, and to further precipitate this phase in nanometer arrays within the grains. Therein, the 2nd phase \β plays the following roles: (1) retarding grain growth, (2) randomizing texture, (3) Hall\–Petch hardening, (4) Orowan hardening, and (5) moderating corrosion. Porosity is a detrimental 2nd phase common to cast Mg alloys in the form of gas or voids; its control being essential to engineering applications. Porosity can be diminished by sub-liquidus molding with high-velocity/high-pressure injection and then eliminated by subsequent hot deformation.

}, issn = {15431851}, doi = {10.1007/s11837-019-03482-z}, url = {https://doi.org/10.1007/s11837-019-03482-z}, author = {Decker, R. F. and Berman, T. D. and Miller, V. M. and Jones, J. W. and Pollock, T. M. and LeBeau, S. E.} } @article {1351, title = {BisQue for 3D Materials Science in the Cloud: Microstructure{\textendash}Property Linkages}, journal = {Integrating Materials and Manufacturing Innovation}, volume = {8}, year = {2019}, pages = {52{\textendash}65}, abstract = {

Accelerating the design and development of new advanced materials is one of the priorities in modern materials science. These efforts are critically dependent on the development of comprehensive materials cyberinfrastructures which enable efficient data storage, management, sharing, and collaboration as well as integration of computational tools that help establish processing\–structure\–property relationships. In this contribution, we present implementation of such computational tools into a cloud-based platform called BisQue (Kvilekval et al., Bioinformatics 26(4):554, 2010). We first describe the current state of BisQue as an open-source platform for multidisciplinary research in the cloud and its potential for 3D materials science. We then demonstrate how new computational tools, primarily aimed at processing\–structure\–property relationships, can be implemented into the system. Specifically, in this work, we develop a module for BisQue that enables microstructure-sensitive predictions of effective yield strength of two-phase materials. Towards this end, we present an implementation of a computationally efficient data-driven model into the BisQue platform. The new module is made available online (web address: https://bisque.ece.ucsb.edu/module_service/Composite_Strength/) and can be used from a web browser without any special software and with minimal computational requirements on the user end. The capabilities of the module for rapid property screening are demonstrated in case studies with two different methodologies based on datasets containing 3D microstructure information from (i) synthetic generation and (ii) sampling large 3D volumes obtained in experiments.

}, keywords = {Cloud-based computing, Homogenization, Materials cyberinfrastructure, Reduced order models}, isbn = {4019201900}, issn = {21939772}, doi = {10.1007/s40192-019-00128-5}, author = {Latypov, Marat I. and Khan, Amil and Lang, Christian A. and Kvilekval, Kris and Polonsky, Andrew T. and Echlin, McLean L.P. and Beyerlein, Irene J. and Manjunath, B. S. and Pollock, Tresa M.} } @article {1386, title = {Computational homogenization for multiscale forward modeling of resonant ultrasound spectroscopy of heterogeneous materials}, journal = {Materials Characterization}, volume = {158}, year = {2019}, pages = {109945}, abstract = {

We present a computational framework for multiscale forward modeling of ultrasound resonance in heterogeneous materials that accounts for microstructure. The approach includes two steps. The first step is the accurate determination of the elastic properties of heterogeneous materials with finite element simulations on a representative volume element of the microstructure at the mesoscopic length scale. The second step is modeling resonance frequencies of a macroscopic component made of an effective homogeneous medium having the same elastic properties as the actual material with microstructure. The approach is validated in a case study on a Cu\–W two-phase composite, for which resonance frequencies predicted with the proposed framework are compared against the experimental measurements. The present multiscale modeling approach, involving computational homogenization and leveraging 3D microstructure data, showed better accuracy compared to classical Voigt/Reuss bounds often used for forward modeling of resonant ultrasound spectroscopy.

}, keywords = {Computational homogenization, Finite elements, Forward modeling, Non-destructive evaluation, Resonant ultrasound spectroscopy}, issn = {10445803}, doi = {10.1016/j.matchar.2019.109945}, url = {https://doi.org/10.1016/j.matchar.2019.109945}, author = {Latypov, Marat I. and Charpagne, Marie Agathe and Souther, Mason and Goodlet, Brent R. and Echlin, Mclean P. and Beyerlein, Irene J. and Pollock, Tresa M.} } @article {1516, title = {Correction of Electron Back-scattered Diffraction datasets using an evolutionary algorithm}, journal = {arXiv}, year = {2019}, pages = {1{\textendash}10}, abstract = {

In materials science and particularly electron microscopy, Electron Back-scatter Diffraction (EBSD) is a common and powerful mapping technique for collecting local crystallographic data at the sub-micron scale. The quality of the reconstruction of the maps is critical to study the spatial distribution of phases and crystallographic orientation relationships between phases, a key interest in materials science. However, EBSD data is known to suffer from distortions that arise from several instrument and detector artifacts. In this paper, we present an unsupervised method that corrects those distortions, and enables or enhances phase differentiation in EBSD data. The method uses a segmented electron image of the phases of interest (laths, precipitates, voids, inclusions) gathered using detectors that generate less distorted data, of the same area than the EBSD map, and then searches for the best transformation to correct the distortions of the initial EBSD data. To do so, the Covariance Matrix Adaptation Evolution Strategy (CMA-ES) is implemented to distort the EBSD until it matches the reference electron image. Fast and versatile, this method does not require any human annotation and can be applied to large datasets and wide areas, where the distortions are important. Besides, this method requires very little assumption concerning the shape of the distortion function. Some application examples in multiphase materials with feature sizes down to 1 \$\backslashmu\$m are presented, including a Titanium alloy and a Nickel-base superalloy.

}, url = {http://arxiv.org/abs/1903.02982}, author = {Strub, Florian and Charpagne, Marie-agathe and Pollock, Tresa M.} } @article {1396, title = {Creep resistance of bulk copper{\textendash}niobium composites: An inverse effect of multilayer length scale}, journal = {Acta Materialia}, volume = {176}, year = {2019}, pages = {189{\textendash}198}, abstract = {

Metallic multilayer systems show promising performance in extreme environments, with high stability of bi-metal interfaces down to nanometer length scales. The creep behavior of bulk, accumulative roll bonded (ARB) Copper\–Niobium (Cu\–Nb) composites has been studied at 400 \°C as a function of layer thickness, ranging from 2 \μm to 65 nm. Similar to single phase metallic systems, three regimes are observed during creep: transient, steady-state and tertiary. The mechanism controlling minimum creep rate for all conditions tested has a strong dependence on stress, consistent with dislocation-dominated creep. Unlike the conventional effect of grain size on creep resistance, this study reveals that decreasing length scale increases creep resistance.

}, keywords = {Creep, Cu-Nb, Length scale, Multilayer}, issn = {13596454}, doi = {10.1016/j.actamat.2019.06.029}, url = {https://doi.org/10.1016/j.actamat.2019.06.029}, author = {Avallone, Jaclyn T. and Nizolek, Thomas J. and Bales, Benjamin B. and Pollock, Tresa M.} } @article {1356, title = {Dislocation dynamics in a nickel-based superalloy via in-situ transmission scanning electron microscopy}, journal = {Acta Materialia}, volume = {168}, year = {2019}, pages = {152{\textendash}166}, abstract = {

Micro-tensile specimens of nickel-based superalloy oligocrystals were tested in-situ in an scanning electron microscope in transmission mode (TSEM) enabling observation of dislocations. The dynamics of dislocation motion during tensile loading were captured and correlated with the measured intermittencies during plastic flow recorded by high load- and temporal-resolution sensors. This investigation in particular focused on the dislocation behavior near twin boundaries with different slip configurations. A multiplicity of deformation mechanisms at the dislocation scale were observed within individual slip bands, including precipitate shearing, dislocation decorrelation and antiphase boundary-coupled shearing. These processes affect strain localization near twin boundaries and provide new defect-level insights on plastic localization and fatigue crack initiation in these alloys.

}, keywords = {Dislocations dynamic, In-situ transmission scanning electron microscopy (TSEM), Nickel-based superalloy ren{\'e} 88DT, Plastic localization, STEM detector, Twin boundary}, issn = {13596454}, doi = {10.1016/j.actamat.2018.12.061}, url = {https://doi.org/10.1016/j.actamat.2018.12.061}, author = {Stinville, J. C. and Yao, Eric R. and Callahan, Patrick G. and Shin, Jungho and Wang, Fulin and Echlin, Mclean P. and Pollock, Tresa M. and Gianola, Daniel S.} } @article {1371, title = {The evolving landscape for alloy design}, journal = {MRS Bulletin}, volume = {44}, year = {2019}, pages = {238{\textendash}246}, abstract = {

The discovery, design, and development of new alloys have long been critical elements of advanced engineering systems. Challenged by their chemical and structural complexity, this design process is, however, often too slow. This article highlights progress in theory, computation, data, and advanced experimental techniques that are advancing our capabilities for rapid discovery and design of new multicomponent alloys. Applied across the length scales, these new capabilities support exploration across broad composition spaces; examples of new materials and associated advances in the understanding of underlying thermochemical and thermomechanical phenomena are presented. We highlight current challenges, gaps, and specific areas that, if further developed, could have future high payoff.

}, keywords = {alloys, crystallographic structure, electronic structure, phase equilibria, simulation}, issn = {08837694}, doi = {10.1557/mrs.2019.69}, author = {Pollock, Tresa M. and Van der Ven, Anton} } @article {1501, title = {In-plane and out-of-plane deformation at the sub-grain scale in polycrystalline materials assessed by confocal microscopy}, journal = {Acta Materialia}, volume = {169}, year = {2019}, pages = {260{\textendash}274}, abstract = {

High-resolution digital image correlation (HR-DIC) techniques have become essential in material mechanics to assess strain measurements at the scale of the elementary mechanisms responsible of the deformation in polycrystalline materials. The purpose of this study is to demonstrate the use of laser scanning confocal microscopy (LSCM) coupled with DIC techniques to deepen knowledge on the deformation process of a polycrystalline nickel-based superalloy at room temperature. The LSCM technique is capable of detecting both in-plane and out-of-plane strain localization within slip bands at the sub-grain level. The LSCM observations are consistent with previous in-situ scanning electron microscopy (SEM) studies: The onset of crystal plasticity occurs primarily near \Σ3 twin boundaries with macroscopic loading in the elastic domain (macroscopic stress as low as 80\% of the 0.2\% offset yield strength (Y.S. 0.2\% )). This intense irreversible strain localization occurs with either a high Schmid factor (\μ \> 0.43) or a significant elastic modulus difference between the pair of twins (\Δ\Ε \> 100 GPa). In the plastic deformation domain, transgranular slip activity following slip systems with the highest Schmid factor is mostly responsible for the deformation at the grain level, thus leading to strain percolation. The simultaneous in-plane and out-of-plane deformation assessment via the HR-LSCM-DIC technique was found to be essential for the identification of active slip systems. Finally, the HR-LSCM-DIC technique enabled the quantification of the glide amplitude involved in the three-dimensional shearing process at the grain level that solely in-plane measurements cannot provide.

}, keywords = {High Resolution-Digital Image Correlation (HR-DIC), In-situ tensile testing, Laser scanning confocal microscopy (LSCM), Nickel-based polycrystalline superalloy, Strain localization}, issn = {13596454}, doi = {10.1016/j.actamat.2019.03.001}, url = {https://doi.org/10.1016/j.actamat.2019.03.001}, author = {Liu, J. H. and Vanderesse, N. and Stinville, J. C. and Pollock, T. M. and Bocher, P. and Texier, D.} } @article {1381, title = {A model for high temperature deformation of nanolaminate Cu-Nb composites}, journal = {Materials Science and Engineering A}, volume = {761}, year = {2019}, pages = {138016}, abstract = {

Nanolaminate composites with layer thicknesses down to 65 nm display conventional 3 stage creep behavior with creep resistance increasing as layer thickness decreases. A model for the time dependent high temperature deformation response of Cu-Nb composites is developed, and compared to creep tests performed on multilayers fabricated via accumulative roll bonding (ARB). The model assumes a continuous laminate structure of 50\% Cu and 50\% Nb in which deformation is controlled by stage II creep for the copper (\ε˙cr=A\σn) and plasticity in Nb. Regimes in which composite steady-state creep at constant stress can be achieved are identified. The modeling illustrates that strain-hardening in the niobium plays a critical role in the transient response of the multilayer, which can dominate the creep lifetime. The combination of experiments and models strongly suggest that dislocation climb mechanisms in the copper control the time-response at 400 oC for all layer thicknesses tested.

}, keywords = {Creep model, Cu-Nb, Multilayer composite, Strain hardening}, issn = {09215093}, doi = {10.1016/j.msea.2019.06.026}, url = {https://doi.org/10.1016/j.msea.2019.06.026}, author = {Avallone, Jaclyn T. and Nizolek, Thomas J. and Pollock, Tresa M. and Begley, Matthew R.} } @article {1521, title = {New frontiers for the materials genome initiative}, journal = {npj Computational Materials}, volume = {5}, year = {2019}, pages = {1{\textendash}23}, abstract = {

The Materials Genome Initiative (MGI) advanced a new paradigm for materials discovery and design, namely that the pace of new materials deployment could be accelerated through complementary efforts in theory, computation, and experiment. Along with numerous successes, new challenges are inviting researchers to refocus the efforts and approaches that were originally inspired by the MGI. In May 2017, the National Science Foundation sponsored the workshop \“Advancing and Accelerating Materials Innovation Through the Synergistic Interaction among Computation, Experiment, and Theory: Opening New Frontiers\” to review accomplishments that emerged from investments in science and infrastructure under the MGI, identify scientific opportunities in this new environment, examine how to effectively utilize new materials innovation infrastructure, and discuss challenges in achieving accelerated materials research through the seamless integration of experiment, computation, and theory. This article summarizes key findings from the workshop and provides perspectives that aim to guide the direction of future materials research and its translation into societal impacts.

}, issn = {20573960}, doi = {10.1038/s41524-019-0173-4}, url = {http://dx.doi.org/10.1038/s41524-019-0173-4}, author = {de Pablo, Juan J. and Jackson, Nicholas E. and Webb, Michael A. and Chen, Long Qing and Moore, Joel E. and Morgan, Dane and Jacobs, Ryan and Pollock, Tresa and Schlom, Darrell G. and Toberer, Eric S. and Analytis, James and Dabo, Ismaila and DeLongchamp, Dean M. and Fiete, Gregory A. and Grason, Gregory M. and Hautier, Geoffroy and Mo, Yifei and Rajan, Krishna and Reed, Evan J. and Rodriguez, Efrain and Stevanovic, Vladan and Suntivich, Jin and Thornton, Katsuyo and Zhao, Ji Cheng} } @article {1391, title = {Oxidation Behavior Across Composition Space Relevant to Co-based γ/γ' Alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {50}, year = {2019}, pages = {5445{\textendash}5458}, issn = {1073-5623}, doi = {10.1007/s11661-019-05413-8}, url = {https://doi.org/10.1007/s11661-019-05413-8}, author = {Stewart, Colin A. and Suzuki, Akane and Rhein, Robert K. and Pollock, Tresa M. and Levi, Carlos G.} } @article {1376, title = {Protocols for High Temperature Assisted-Microwave Preparation of Inorganic Compounds}, journal = {Chemistry of Materials}, volume = {31}, year = {2019}, pages = {7151{\textendash}7159}, abstract = {

Assisted-microwave heating involves the use of a susceptor to initially heat up reactants in a microwave reaction. Once hot, the reactants themselves become directly susceptible to microwave heating and interdiffuse to form products. Assisted-microwave methods are appealing for a wide variety of high temperature solid-state reactions, reaching reaction temperatures of 1500 \°C and more. Among the many advantages are that the direct volumetric heating associated with microwaves allows for rapid reaction times while employing significantly less energy than conventional furnace-based preparation. Shorter reaction times and selective heating permit volatile reactants to be incorporated stoichiometrically in the product. Undesirable reactions with containers or enclosures are also minimized. The morphology of powders obtained through microwave reactions are also more uniform and comprise smaller particles than obtained conventionally. This Methods/Protocols article is presented as a user manual for carrying out assisted-microwave preparation of bulk complex oxides in air or reducing atmospheres and sol-gel based processing of complex oxides, air sensitive intermetallics, and transition metal chalcogenides.

}, issn = {15205002}, doi = {10.1021/acs.chemmater.9b02594}, author = {Levin, Emily E. and Grebenkemper, Jason H. and Pollock, Tresa M. and Seshadri, Ram} } @article {1496, title = {Short crack propagation from cracked non-metallic inclusions in a Ni-based polycrystalline superalloy}, journal = {Acta Materialia}, volume = {165}, year = {2019}, pages = {241{\textendash}258}, abstract = {

Fatigue cracks initiating from surface and sub-surface non-metallic inclusions (NMIs) have recently been demonstrated to be a necessary but not sufficient explanation for atypically short low-cycle fatigue life in Inconel 718 alloy at intermediate temperature. Therefore, the early stages of short crack propagation from surface NMIs were investigated in a crystallographic and two-dimensional versus three-dimensional morphological manner after room temperature low cycle fatigue (LCF) testing. In the present investigation, NMIs were purposely pre-cracked using different techniques to suppress the natural crack initiation period and thus the incubation period prior to the early stages of crack propagation. Under such fatigue testing conditions, different mechanisms of crack transmission from pre-cracked NMIs were identified: (i) no propagation, (ii) NMI/adjacent metallic grain interfacial debonding, (iii) transgranular crack propagation within the adjacent metallic grain. Focused-ion-beam cross-section observations of numerous fatigue tested NMIs aimed to define a morphological criterion for non-propagating NMIs. Large cracked NMIs at the surface (2c) with limited extension into the depth (a) did not propagate under such fatigue conditions for 2c/a ratio higher than 3. Furthermore, specific crystallographic relationships between NMIs and the adjacent metallic grain explained different crack propagation configurations from pre-cracked NMIs, i.e. interfacial debonding and transgranular crack propagation involving single or multiple-slip activity.

}, keywords = {Focus-ion-beam cross-section (FIB-cross section), Low cycle fatigue, Non-metallic inclusions, Short crack propagation, Superalloy 718DA}, issn = {13596454}, doi = {10.1016/j.actamat.2018.11.051}, author = {Texier, Damien and Stinville, Jean Charles and Echlin, Mclean P. and Pierret, St{\'e}phane and Villechaise, Patrick and Pollock, Tresa M. and Cormier, Jonathan} } @article {1361, title = {Three-dimensional Analysis and Reconstruction of Additively Manufactured Materials in the Cloud-Based BisQue Infrastructure}, journal = {Integrating Materials and Manufacturing Innovation}, volume = {8}, year = {2019}, pages = {37{\textendash}51}, abstract = {

A microstructure analytics and 3D reconstruction software package, DREAM.3D, was integrated as a module into a cloud-based platform, BisQue. Parallelization of DREAM.3D module executions and the ability to parameterize pipeline variables over a range of values have led to insights about the grain segmentation misorientation tolerance in TriBeam-collected 3D EBSD datasets of additively manufactured materials with complex anisotropic microstructures. Furthermore, a comparison in grain size measurements was made between standard 2D metallographic slices and 3D measures using BisQue\&$\#$39;s parallelized DREAM.3D module executions. The direction of cloud-based data infrastructure and the prospects for impact in material science are also discussed.

}, keywords = {3D materials science, 3D metal printing, Additive manufacturing, Cloud infrastructure, Microstructure analytics, Tomography}, isbn = {4019201900}, issn = {21939772}, doi = {10.1007/s40192-019-00126-7}, author = {Polonsky, Andrew T. and Lang, Christian A. and Kvilekval, Kristian G. and Latypov, Marat I. and Echlin, McLean L.P. and Manjunath, B. S. and Pollock, Tresa M.} } @article {1431, title = {Advanced detector signal acquisition and electron beam scanning for high resolution SEM imaging}, journal = {Ultramicroscopy}, volume = {195}, year = {2018}, pages = {93{\textendash}100}, abstract = {

The advancement of materials science at the mesoscale requires improvements in both sampling volumes/areas and spatial resolution in order to make statistically significant measurements of microstructures that influence higher-order material properties, such as fatigue and fracture. Therefore, SEM-based techniques have become desirable due to improvements in imaging resolution, large sample handling capability, and flexibility for in-situ instrumentation. By using fast sampling of SEM electron detector signals, intrinsic beam scanning defects have been identified that are related to the response time of the SEM electron beam deflectors and electron detectors. Mitigation of these beam scanning defects using detector sampling approaches and an adaptive model for settling time is shown to produce higher resolution SEM images, at faster image acquisition times, with a means to quantify the different response functions for various beam deflectors and detectors including those for electrons and ions.

}, keywords = {High resolution digital image correlation, Image processing, Imaging defects, Scan generator, Scanning electron microscopy, SEM}, issn = {18792723}, doi = {10.1016/j.ultramic.2018.08.025}, url = {https://doi.org/10.1016/j.ultramic.2018.08.025}, author = {Lenthe, William C. and Stinville, Jean Charles and Echlin, Mclean P. and Chen, Zhe and Daly, Samantha and Pollock, Tresa M.} } @article {1471, title = {Application of chord length distributions and principal component analysis for quantification and representation of diverse polycrystalline microstructures}, journal = {Materials Characterization}, volume = {145}, year = {2018}, pages = {671{\textendash}685}, abstract = {

Quantification of mesoscale microstructures of polycrystalline materials is important for a range of practical tasks of materials design and development. The current protocols of quantifying grain size and morphology often rely on microstructure metrics (e.g., mean grain diameter) that overlook important details of the mesostructure. In this work, we present a quantification framework based on directionally resolved chord length distribution and principal component analysis as a means of extracting additional information from 2-D microstructural maps. Towards this end, we first present in detail a method for calculating chord length distribution based on boundary segments available in modern digital datasets (e.g., from microscopy post-processing) and their low-rank representations by principal component analysis. The utility of the proposed framework for capturing grain size, morphology, and their anisotropy for efficient visualization, representation, and specification of polycrystalline microstructures is then demonstrated in case studies on datasets from synthetic generation, experiments (on Ni-base superalloys), and simulations (on steel during recrystallization).

}, keywords = {Chord length distribution, EBSD, Grain size, Microstructure, Principal component analysis}, issn = {10445803}, doi = {10.1016/j.matchar.2018.09.020}, url = {https://doi.org/10.1016/j.matchar.2018.09.020}, author = {Latypov, Marat I. and K{\"u}hbach, Markus and Beyerlein, Irene J. and Stinville, Jean Charles and Toth, Laszlo S. and Pollock, Tresa M. and Kalidindi, Surya R.} } @article {1426, title = {Bayesian inference of elastic properties with resonant ultrasound spectroscopy}, journal = {The Journal of the Acoustical Society of America}, volume = {143}, year = {2018}, pages = {71{\textendash}83}, abstract = {

\© 2018 Acoustical Society of America. Bayesian modeling and Hamiltonian Monte Carlo (HMC) are utilized to formulate a robust algorithm capable of simultaneously estimating anisotropic elastic properties and crystallographic orientation of a specimen from a list of measured resonance frequencies collected via Resonance Ultrasound Spectroscopy (RUS). Unlike typical optimization procedures which yield point estimates of the unknown parameters, computing a Bayesian posterior yields probability distributions for the unknown parameters, and HMC is an efficient way to compute this posterior. The algorithms described are demonstrated on RUS data collected from two parallelepiped specimens of structural metal alloys. First, the elastic constants for a specimen of fine-grain polycrystalline Ti-6Al-4 V with random crystallographic texture and isotropic elastic symmetry are estimated. Second, the elastic constants and crystallographic orientation for a single crystal Ni-based superalloy CMSX-4 specimen are accurately determined, using only measurements of the specimen geometry, mass, and resonance frequencies. The unique contributions of this paper are as follows: the application of HMC for sampling the Bayesian posterior of a probabilistic RUS model, and the procedure for simultaneous estimation of elastic constants and lattice-specimen misorientation. Compared to previous approaches these algorithms demonstrate superior convergence behavior, particularly when the initial parameterization is unknown, and enable substantially simplified experimental procedures.

}, issn = {0001-4966}, doi = {10.1121/1.5017840}, author = {Bales, Ben and Petzold, Linda and Goodlet, Brent R. and Lenthe, William C. and Pollock, Tresa M.} } @article {1441, title = {Competing Modes for Crack Initiation from Non-metallic Inclusions and Intrinsic Microstructural Features During Fatigue in a Polycrystalline Nickel-Based Superalloy}, journal = {Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science}, volume = {49}, year = {2018}, pages = {3865{\textendash}3873}, abstract = {

Cyclic fatigue experiments in the high and very high cycle fatigue regimes have been performed on a Ren\é 88DT polycrystalline nickel-based superalloy. The microstructural configurations that favor early strain localization and fatigue crack initiation at high temperature from 400\ \°C to 650\ \°C have been investigated. Competing failure modes are observed in the high to the very high cycle fatigue regime. Fatigue cracks initiate from non-metallic inclusions and from intrinsic internal microstructural features. Interestingly, as stresses are reduced into the very high cycle regime, there is a transition to initiation only at crystallographic facets. At higher stress in the high cycle fatigue regime, a significant fraction of specimens initiate cracks at non-metallic inclusions. This transition is analyzed with regard to microstructural features that favor strain localization and accumulate damage early during cycling.

}, isbn = {1166101847803}, issn = {10735623}, doi = {10.1007/s11661-018-4780-3}, url = {https://doi.org/10.1007/s11661-018-4780-3}, author = {Stinville, Jean Charles and Martin, Etienne and Karadge, Mallikarjun and Ismonov, Shak and Soare, Monica and Hanlon, Tim and Sundaram, Sairam and Echlin, McLean L.P. and Callahan, Patrick G. and Lenthe, William C. and Miao, Jiashi and Wessman, Andrew E. and Finlay, Rebecca and Loghin, Adrian and Marte, Judson and Pollock, Tresa M.} } @article {1316, title = {Creep Behavior of Quinary γ'-Strengthened Co-Based Superalloys}, journal = {Metallurgical and Materials Transactions A}, volume = {49}, year = {2018}, pages = {4090{\textendash}4098}, issn = {1073-5623}, doi = {10.1007/s11661-018-4768-z}, url = {http://link.springer.com/10.1007/s11661-018-4768-z}, author = {Rhein, Robert K. and Callahan, Patrick G. and Murray, Sean P. and Stinville, Jean-Charles and Titus, Michael S. and Van der Ven, Anton and Pollock, Tresa M.} } @article {1326, title = {Defects and 3D structural inhomogeneity in electron beam additively manufactured Inconel 718}, journal = {Materials Characterization}, volume = {143}, year = {2018}, pages = {171{\textendash}181}, abstract = {

Material structure and defects created during additive manufacturing contribute to the variability in mechanical properties of these parts, limiting their use for critical applications. Three-dimensional crystallographic, structural, and chemical information in electron beam melted Inconel 718 was collected from the sub-micron to the millimeter scale using the TriBeam tomography system. The relationship of defects to the surrounding microstructure has been studied in detail. Lack of fusion defects created sharp discontinuities in the grain morphology that extended several build layers beyond the layer where the defect originated. Nitrides and carbides in the size range of 1.25 \μm to 10 \μm were observed throughout the volume, with pronounced nitride clustering. The similarities between solidification in additive manufacturing and traditional manufacturing processes are demonstrated by the comparable size and distribution of carbides measured for industrial-scale samples of 718. Defects created during additive manufacturing cannot be easily remedied via standard post-processing techniques, and will likely diminish the mechanical performance of additively manufactured parts.

}, keywords = {Additive manufacturing, Electron beam melting, Lack of fusion, Microstructure, Tomography}, issn = {10445803}, doi = {10.1016/j.matchar.2018.02.020}, author = {Polonsky, Andrew T. and Echlin, Mclean P. and Lenthe, William C. and Dehoff, Ryan R. and Kirka, Michael M. and Pollock, Tresa M.} } @article {1466, title = {Designing nickel base alloys for microstructural stability through low γ-γ' interfacial energy and lattice misfit}, journal = {Materials and Design}, volume = {140}, year = {2018}, pages = {249{\textendash}256}, abstract = {

An extended stability alloy design strategy for multicomponent \γ-\γ\′ nickel-base alloys with near-zero lattice misfit and as low as possible interfacial energy was investigated by isothermal annealing of two experimental alloys at 900 \°C for times up to 256 h. The coarsening behavior of the spherical \γ\′ precipitates and the phase compositions determined by atom probe tomography were utilized to exploit a modified Lifshitz-Slyozov-Wagner relationship to estimate the interfacial energies. The estimated interfacial energies are much lower than predicted by a CALPHAD-based software as well as those typically reported for multicomponent \γ-\γ\′ nickel alloys. Despite successfully minimizing the interfacial energy and \γ-\γ\′ lattice misfit, these factors alone were not sufficient to impart high temperature extended stability through reduced coarsening kinetics.

}, keywords = {Atom probe tomography, Interfacial energy, Precipitate coarsening, γ-γ' nickel-base alloy}, issn = {18734197}, doi = {10.1016/j.matdes.2017.11.065}, url = {http://dx.doi.org/10.1016/j.matdes.2017.11.065}, author = {Meher, S. and Carroll, M. C. and Pollock, T. M. and Carroll, L. J.} } @article {1166, title = {Discrete dislocation plasticity analysis of the high-temperature cyclic response of composites}, journal = {Materials Science and Engineering: A}, volume = {712}, year = {2018}, pages = {714{\textendash}719}, doi = {10.1016/j.msea.2017.12.034}, author = {Shishvan, Siamak S. and Mcmeeking, Robert M. and Pollock, Tresa M. and Deshpande, Vikram S.} } @article {1311, title = {Elastic Properties of Novel Co- and CoNi-Based Superalloys Determined through Bayesian Inference and Resonant Ultrasound Spectroscopy}, journal = {Metallurgical and Materials Transactions A}, volume = {49A}, year = {2018}, month = {06/2018}, pages = {2324{\textendash}2339}, issn = {1543-1940}, doi = {10.1007/s11661-018-4575-6}, url = {https://doi.org/10.1007/s11661-018-4575-6}, author = {Goodlet, Brent R and Mills, Leah and Bales, Ben and Charpagne, Marie-agathe and Murray, Sean P and Lenthe, William C and Petzold, Linda and Pollock, Tresa M} } @article {1421, title = {Enhancing thermoelectric properties through control of Nickel Interstitials and phase separation in Heusler/Half-Heusler TiNi1.1Sn composites}, journal = {Materials}, volume = {11}, year = {2018}, pages = {1{\textendash}12}, abstract = {

Thermoelectric devices, which allow direct conversion of heat into electrical energy, require materials with improved figures of merit (zT) in order to ensure widespread adoption. Several techniques have been proposed to increase the zT of known thermoelectric materials through the reduction of thermal conductivity, including heavy atom substitution, grain size reduction and inclusion of a semicoherent second phase. The goal in these approaches is to reduce thermal conductivity through phonon scattering without modifying the electronic properties. In this work, we demonstrate that Ni interstitials in the half-Heusler thermoelectric TiNiSn can be created and controlled in order to improve physical properties. Ni interstitials in TiNi1.1Sn are not thermodynamically stable and, instead, are kinetically trapped using appropriate heat treatments. The Ni interstitials, which act as point defect phonon scattering centers and modify the electronic states near the Fermi level, result in reduced thermal conductivity and enhance the Seebeck coefficient. The best materials tested here, created from controlled heat treatments of TiNi1.1Sn samples, display zT = 0.26 at 300 K, the largest value reported for compounds in the Ti-Ni-Sn family.

}, keywords = {Heusler, Phonon scattering, Point defect, Thermoelectric, TiNi2Sn, TiNiSn}, issn = {19961944}, doi = {10.3390/ma11060903}, author = {Levin, Emily E. and Long, Francesca and Douglas, Jason E. and Buffon, Malinda L.C. and Lamontagne, Leo K. and Pollock, Tresa M. and Seshadri, Ram} } @article {1346, title = {Fatigue deformation in a polycrystalline nickel base superalloy at intermediate and high temperature: Competing failure modes}, journal = {Acta Materialia}, volume = {152}, year = {2018}, pages = {16{\textendash}33}, abstract = {

The microstructural configurations that favor early strain localization and fatigue crack initiation at intermediate and high temperature (400 \°C\–650 \°C) have been investigated using novel experimental techniques, including high resolution digital image correlation and transmission scanning electron microscopy. Cyclic fatigue experiments in the high and low cycle fatigue regimes have been performed on a Ren\é 88DT polycrystalline nickel-base superalloy at temperatures up to 650 \°C and compared to previous fatigue results obtained from tests in the very high cycle fatigue regime. Competing failure modes are observed along with an inversion in the temperature fatigue life dependence of fatigue strength from the low to high cycle fatigue regime. Oxidation-assisted processes are dominant at high applied stresses while cyclic plastic localization and accumulation govern fracture at low applied stresses. In addition, a second competing mode exists in the high and very high cycle fatigue regime from non-metallic inclusions as compared to internal intrinsic initiation sites. The grain-scale features that exhibit strain localization and crack initiation were investigated in detail. Transmission electron microscopy (TEM), transmission scanning electron microscopy (TSEM) and electron channeling contrast imaging have been conducted on samples removed from targeted regions with microstructural configurations that favor crack initiation to characterize the associated dislocation sub-structure and its evolution with temperature. Plasticity is observed to be less localized during cyclic loading at high temperature compared to room temperature. The microstructural features that drive initiation across the temperature range investigated are: twin-parent grains pairs that are at the upper end of the size distribution, are oriented for near maximum elastic modulus mismatch, and have high stresses along planes parallel to the twin boundaries.

}, keywords = {Coherent twin boundary, Elastic anisotropy, Fatigue crack initiation at intermediate and high temperature, High resolution digital image correlation, Microstructural effect, Polycrystalline microstructure, Ren{\'e} 88DT polycrystalline superalloy, Strain localization}, issn = {13596454}, doi = {10.1016/j.actamat.2018.03.035}, url = {https://doi.org/10.1016/j.actamat.2018.03.035}, author = {Stinville, Jean Charles and Martin, Etienne and Karadge, Mallikarjun and Ismonov, Shak and Soare, Monica and Hanlon, Tim and Sundaram, Sairam and Echlin, Mclean P. and Callahan, Patrick G. and Lenthe, William C. and Miller, V. M. and Miao, Jiashi and Wessman, Andrew E. and Finlay, Rebecca and Loghin, Adrian and Marte, Judson and Pollock, Tresa M.} } @article {1486, title = {Femtosecond laser rejuvenation of nanocrystalline metals}, journal = {Acta Materialia}, volume = {156}, year = {2018}, pages = {183{\textendash}195}, abstract = {

Nanocrystalline metals are distinct from traditional engineering materials due to their high concentration of grain boundaries and corresponding structural disorder at grain boundaries. The effect of local disorder in nanocrystalline materials manifests in ways reminiscent of fully amorphous materials, such as mesoscale shear localization and pressure-dependent yielding, owing to the high concentration of grain boundaries and their predominance in governing plasticity. Relaxation processes in nanocrystalline materials that facilitate reconfigurations of grain boundaries and lower their energy, such as low temperature annealing, have been shown to enhance mechanical strength. However, processes that raise the energy of a nanocrystalline metal have not been observed, limiting the tunability of properties and the prospect for suppressing shear localization. Here, we use femtosecond laser processing as a unique non-equilibrium process that can generate complex stress states due to ultrafast electronic excitation and subsequent relaxation events. Experiments on nanocrystalline Al-O and Cu-Zr alloys indicate that sub-ablation femtosecond laser pulses cause up to an 87\% reduction in hardness with no change in grain size, which can be ascribed to grain boundary-mediated processes. Parallels between our results and rejuvenation processes in glassy systems will be discussed in the context of controlling metastable structural configurations through novel processing routes.

}, keywords = {Femtosecond lasers, Grain boundaries, Nanocrystalline, Rejuvenation}, issn = {13596454}, doi = {10.1016/j.actamat.2018.06.027}, url = {https://doi.org/10.1016/j.actamat.2018.06.027}, author = {Balbus, Glenn H. and Echlin, Mclean P. and Grigorian, Charlette M. and Rupert, Timothy J. and Pollock, Tresa M. and Gianola, Daniel S.} } @article {1451, title = {Grain size effects on NiTi shape memory alloy fatigue crack growth}, journal = {Journal of Materials Research}, volume = {33}, year = {2018}, pages = {91{\textendash}107}, abstract = {

Fatigue cracking in polycrystalline NiTi was investigated using a multiscale experimental framework for average grain sizes (GS) from 10 to 1500 nm for the first time. Macroscopic fatigue crack growth rates, measured by optical digital image correlation, were connected to microscopic crack opening and closing displacements, measured by scanning electron microscope DIC (SEM-DIC) using a high-precision external SEM scan controller. Among all grain sizes, the 1500 nm GS sample exhibited the slowest crack growth rate at the macroscale, and the largest crack opening level (stress intensity at first crack opening) and minimum crack opening displacements at the microscale. Smaller GS samples (10, 18, 42, and 80 nm) exhibited nonmonotonic trends in their fatigue performance, yet the correlation was strong between macroscale and microscale behaviors for each GS. The samples that exhibited the fastest crack growth rates (42 and 80 nm GS) showed a small crack opening level and the largest crack opening displacements. The irregular trends in fatigue performance across the nanocrystalline GS samples were consistent with nonmonotonic values in the elastic modulus reported previously, both of which may be related to the presence of residual martensite only evident in the small GS samples (10 and 18 nm).

}, keywords = {fatigue, nanostructure, scanning electron microscopy (SEM)}, issn = {20445326}, doi = {10.1557/jmr.2017.395}, author = {Lepage, William S. and Ahadi, Aslan and Lenthe, William C. and Sun, Qing Ping and Pollock, Tresa M. and Shaw, John A. and Daly, Samantha H.} } @article {1461, title = {High-Resolution Deformation Mapping Across Large Fields of View Using Scanning Electron Microscopy and Digital Image Correlation}, journal = {Experimental Mechanics}, volume = {58}, year = {2018}, pages = {1407{\textendash}1421}, abstract = {

This paper details the creation of experimental and computational frameworks to capture high-resolution, microscale deformation mechanisms and their relation to microstructure over large (mm-scale) fields of view. Scanning electron microscopy with custom automation and external beam control was used to capture 209 low-distortion micrographs of 360\ \μm \× 360\ \μm each, that were individually correlated using digital image correlation to obtain displacement/strain fields with a spatial resolution of 0.44\ \μm. Displacement and strain fields, as well as secondary electron images, were subsequently stitched to create a 5.7\ mm\ \×\ 3.4\ mm field of view containing 100 million (7678 \× 13,004) data points. This approach was demonstrated on Mg WE43 under uniaxial compression, where effective strain was shown to be relatively constant with respect to distance from the grain boundary, and a noticeable increase in the effective strain was found with an increase in the basal Schmid factor. The ability to obtain high-resolution deformations over statistically relevant fields of view enables large data analytics to examine interactions between microstructure, microscale strain localizations, and macroscopic properties.

}, keywords = {Alignment, Digital image correlation (DIC), Distortion, External scan, Stitching}, issn = {17412765}, doi = {10.1007/s11340-018-0419-y}, author = {Chen, Z. and Lenthe, W. and Stinville, J. C. and Echlin, M. and Pollock, T. M. and Daly, S.} } @article {1436, title = {Measurements of plastic localization by heaviside-digital image correlation}, journal = {Acta Materialia}, volume = {157}, year = {2018}, pages = {307{\textendash}325}, abstract = {

In polycrystalline metallic materials, quantitative and statistical assessment of the plasticity in relation to the microstructure is necessary to understand the deformation processes during mechanical loading. Plastic deformation often localizes into physical slip bands at the sub-grain scale. Detrimental microstructural configurations that result in the formation and evolution of slip bands during loading require advanced strain mapping techniques for the identification of these atomically sharp discontinuities. A new discontinuity-tolerant DIC method, Heaviside-DIC, has been developed to account for discontinuities in the displacement field. Displacement fields have been measured at the scale of the physical slip bands over large areas in nickel-based superalloys by high resolution scanning electron microscopy digital image correlation (SEM DIC). However, conventional DIC methods cannot quantitatively measure plastic localization in the presence of discontinuous kinematic fields such as those produced by slip bands. The Heaviside-DIC technique can autonomously detect discontinuities, providing information about their location, inclination, and identify slip systems (in combination with orientation mapping). Using Heaviside-DIC, discontinuities are physically evaluated as sharp shear-localization events, allowing for the quantitative measure of strain amplitude nearby the discontinuities. Measurements using the new Heaviside-DIC technique are compared to conventional DIC methods for identical materials and imaging conditions.

}, keywords = {Discontinuities measurements, High resolution digital image correlation, Ren{\'e} 88DT polycrystalline superalloy, Scanning electron microscopy, Slip band offset, Slip band shearing, Slip system identification, Strain localization}, issn = {13596454}, doi = {10.1016/j.actamat.2018.07.013}, url = {https://doi.org/10.1016/j.actamat.2018.07.013}, author = {Bourdin, F. and Stinville, J. C. and Echlin, M. P. and Callahan, P. G. and Lenthe, W. C. and Torbet, C. J. and Texier, D. and Bridier, F. and Cormier, J. and Villechaise, P. and Pollock, T. M. and Valle, V.} } @article {1456, title = {Microstructure and property based statistically equivalent RVEs for intragranular γ-γ{\textquoteright} microstructures of Ni-based superalloys}, journal = {Acta Materialia}, volume = {157}, year = {2018}, pages = {245{\textendash}258}, abstract = {

This paper develops statistically equivalent RVEs or SERVEs for intragranular microstructures of Ni-based superalloys, characterized by \γ-\γ\&$\#$39; phase distribution. The SERVE represents an optimal computational domain to be used for micromechanical simulations for effective properties or response variables in the microstructure. The SERVE is further classified as a microstructure-based SERVE or M-SERVE or property-based SERVE or P-SERVE, depending on whether the statistics of morphological characteristics or convergence of chosen material properties are its determinants. Starting from FIB-SEM data for the superalloy Ren\é 88DT, the paper systematically develops a host of algorithms for generating validated statistically equivalent virtual microstructures, from which the M-SERVE is estimated from convergence of selected morphological and spatial distributions. Subsequently the P-SERVEs are established for global properties like yield strength and hardening rate, and local variables including dislocation density and the maximum resolved shear stress. Spatially-averaged quantities are found to converge quicker than the local distributions for both M-SERVE and P-SERVE.

}, keywords = {M-SERVE, Ni-based superalloys, P-SERVE, SEVM, Two-point correlation function, γ-γ{\textquoteright} distribution}, issn = {13596454}, doi = {10.1016/j.actamat.2018.07.034}, url = {https://doi.org/10.1016/j.actamat.2018.07.034}, author = {Pinz, M. and Weber, G. and Lenthe, W. C. and Uchic, M. D. and Pollock, T. M. and Ghosh, S.} } @article {1491, title = {Microstructure and Property-Based Statistically Equivalent Representative Volume Elements for Polycrystalline Ni-Based Superalloys Containing Annealing Twins}, journal = {Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science}, volume = {49}, year = {2018}, pages = {5727{\textendash}5744}, abstract = {

This paper has three major objectives related to the development of computational micromechanics models of Ni-based superalloys, containing a large number of annealing twins. The first is the development of a robust methodology for generating 3D statistically equivalent virtual polycrystalline microstructures (3D-SEVPM) of Ni-based superalloys. Starting from electron backscattered diffraction (EBSD) images of sections, the method develops distributions and correlation functions of various morphological and crystallographic parameters. To incorporate twins in the parent grain microstructure, the joint probability of the number of twins and parent grain size, and the conditional probability distributions of twin thickness and twin distance are determined. Subsequently, a method is devised for inserting twins following the distribution functions. The overall methodology is validated by successfully comparing various statistics of the virtual microstructures with 3D EBSD data. The second objective is to establish the microstructure-based statistically equivalent representative volume element or M-SERVE that corresponds to the minimum SERVE size at which the statistics of any morphological or crystallographic feature converge to that of the experimental data. The Kolmogorov\–Smirnov (KS) test is conducted to assess the convergence of the M-SERVE size. The final objective is to estimate the property-based statistically equivalent RVE or P-SERVE, defined as the smallest SERVE, which should be analyzed to predict effective material properties. The crystal plasticity finite-element model is used to simulate SERVEs, from which the overall material response is computed. Convergence plots of material properties including the yield strength and hardening rate are used to assess the P-SERVE. A smaller P-SERVE compared to the M-SERVE indicates that the characteristic features of twins implemented in determining the M-SERVE are more stringent than those for determining material properties.

}, issn = {10735623}, doi = {10.1007/s11661-018-4858-y}, url = {https://doi.org/10.1007/s11661-018-4858-y}, author = {Bagri, Akbar and Weber, George and Stinville, Jean Charles and Lenthe, William and Pollock, Tresa and Woodward, Christopher and Ghosh, Somnath} } @article {1171, title = {Oxidation-Assisted Crack Growth in Single-Crystal Superalloys during Fatigue with Compressive Holds}, journal = {Metallurgical and Materials Transactions A}, volume = {49}, year = {2018}, pages = {105{\textendash}116}, doi = {10.1007/s11661-017-4392-3}, author = {Lafata, M. A. and Rettberg, L. H. and He, M. Y. and Pollock, T. M.} } @article {1481, title = {Prediction of tensile stiffness and strength of Ti-6Al-4V using instantiated volume elements and crystal plasticity}, journal = {Acta Materialia}, volume = {157}, year = {2018}, pages = {21{\textendash}32}, abstract = {

Based on simulations of tensile tests, the macroscopic stiffness and strength of the \α phase of Ti-6Al-4V are estimated. Sets of virtual samples are instantiated using characterization data from three-dimensional electron back-scattered diffraction (EBSD) scans collected with the TriBeam microscope and local properties extracted from in situ loading high-energy x-ray diffraction (HEXD) experiments. The simulations use a crystal-scale finite element framework to compute the mechanical response of the virtual samples under tensile loading. From the simulation data, mechanical properties are extracted from volume elements ranging in size from a fraction of the gage section to its entire length. To detect macroscopic yield, a flood-fill algorithm is used to identify a zone of plastically deformed finite elements extending through a volume element. Trends in the estimated properties as functions of the volume element size are examined. The lower bound of volume element size necessary to replicate experimentally measured macroscale properties is indicated. The technique and results provide a guideline for estimating macroscale property values in components designed with size smaller than the lower bound due to constraint.

}, keywords = {Crystal plasticity finite element, Stiffness, Titanium, Volume element size, Yield detection}, issn = {13596454}, doi = {10.1016/j.actamat.2018.07.011}, url = {https://doi.org/10.1016/j.actamat.2018.07.011}, author = {Chatterjee, Kamalika and Echlin, Mclean P. and Kasemer, Matthew and Callahan, Patrick G. and Pollock, Tresa M. and Dawson, Paul} } @article {1321, title = {Rapid Assessment of Oxidation Behavior in Co-Based γ/γ' Alloys}, journal = {Oxidation of Metals}, volume = {90}, year = {2018}, pages = {485{\textendash}498}, keywords = {Cobalt-base superalloys, Combinatorial synthesis, Oxidation, Photostimulated luminescence spectroscopy}, isbn = {0030-770X}, issn = {0030770X}, doi = {10.1007/s11085-018-9849-2}, url = {https://doi.org/10.1007/s11085-018-9849-2}, author = {Stewart, Colin A. and Suzuki, Akane and Pollock, Tresa M. and Levi, Carlos G.} } @article {1476, title = {Shearing of γ{\textquoteright} particles in Co-base and Co-Ni-base superalloys}, journal = {Acta Materialia}, volume = {161}, year = {2018}, pages = {99{\textendash}109}, abstract = {

Shearing mechanisms of the primary strengthening phase in cobalt-base and cobalt-nickel-base superalloys, \γ\′ (L12), are investigated at the elementary defect level by using a combination of generalized-stacking-fault energy (GSF) calculations and phase field simulations. The GSF energy surfaces of the \γ and \γ\′ phases, as determined from available experimental data and ab initio calculations, are used in the phase field simulations. Sophisticated deformation pathways leading to various planar defects including antiphase boundaries (APB), remnant superlattice intrinsic stacking faults (SISF), APB-SISF-APB ribbons and SISF islands are predicted as a function of alloy composition and particle shapes. The predicted stacking fault configurations for both alloys are consistent with recent transmission electron microscopy observations. Effects of dislocation line tension difference in \γ and \γ\′ phases and planar defect energy variation due to segregation at the planar defects are discussed. The detailed dislocation core structures, effects of dislocation line tension differences on deformation mechanisms, and unique deformation mechanisms uncovered, which include stacking fault ribbon shearing, antiphase boundary shearing, and mixed modes, could be used to improve constitutive microstructure-property relationships in advanced crystal plasticity modeling and to assist in alloy design.

}, keywords = {Ab initio calculation, Dislocation creep, Phase field simulation, Precipitation hardening, Stacking fault ribbon}, issn = {13596454}, doi = {10.1016/j.actamat.2018.09.013}, author = {Feng, L. and Lv, D. and Rhein, R. K. and Goiri, J. G. and Titus, M. S. and Van der Ven, A. and Pollock, T. M. and Wang, Y.} } @article {1176, title = {Transmission Scanning Electron Microscopy: Defect Observations and Image Simulations}, journal = {Ultramicroscopy }, volume = {186}, year = {2018}, chapter = {49}, doi = {https://doi.org/10.1016/j.ultramic.2017.11.004}, author = {Callahan, PG and Stinville, JC and Yao, ER and Echlin, MP and Titus, MS and De Graef, M and Pollock, TM and Gianola, DS} } @article {1211, title = {3D printing of high-strength aluminium alloys}, journal = {Nature}, volume = {549}, year = {2017}, pages = {365{\textendash}369}, doi = {10.1038/nature23894}, author = {Martin, John H. and Yahata, Brennan D. and Hundley, Jacob M. and Mayer, Justin A. and Schaedler, Tobias A. and Pollock, Tresa M.} } @article {1206, title = {Discrete dislocation plasticity analysis of the effect of interfacial diffusion on the creep response of Ni single-crystal superalloys}, journal = {Acta Materialia}, volume = {135}, year = {2017}, pages = {188{\textendash}200}, doi = {10.1016/j.actamat.2017.06.026}, author = {Shishvan, Siamak S. and Mcmeeking, Robert M. and Pollock, Tresa M. and Deshpande, Vikram S.} } @article {1446, title = {Electrically pumped continuous wave quantum dot lasers epitaxially grown on patterned, on-Axis (001) Si}, journal = {Optics Express}, volume = {25}, year = {2017}, pages = {3927{\textendash}3934}, keywords = {III-V on Silicon, Monolithic Integration, Quantum dot lasers, Silicon Photonics}, isbn = {9784885523069}, issn = {08999406}, doi = {10.1364/ol.42.000338}, author = {Norman, Justin and Kennedy, M.J. and Selvidge, Jennifer and Li, Quang and Wan, Yating and Liu, Alan Y. and Callahan, Patrick G. and Echlin, Mclean P. and Pollock, Tresa M. and Lau, Kei May and Gossard, Arthur C. and Bowers, John E.} } @article {1231, title = {Forward models for extending the mechanical damage evaluation capability of resonant ultrasound spectroscopy}, journal = {Ultrasonics}, volume = {77}, year = {2017}, pages = {183{\textendash}196}, doi = {10.1016/j.ultras.2017.02.002}, author = {Goodlet, B.r. and Torbet, C.j. and Biedermann, E.j. and Jauriqui, L.m. and Aldrin, J.c. and Pollock, T.m.} } @article {1261, title = {Interfacial diffusion in high-temperature deformation of composites: A discrete dislocation plasticity investigation}, journal = {Journal of the Mechanics and Physics of Solids}, volume = {98}, year = {2017}, pages = {330{\textendash}349}, doi = {10.1016/j.jmps.2016.09.002}, author = {Shishvan, Siamak S. and Pollock, Tresa M. and Mcmeeking, Robert M. and Deshpande, Vikram S.} } @article {1216, title = {Materials response to glancing incidence femtosecond laser ablation}, journal = {Acta Materialia}, volume = {124}, year = {2017}, pages = {46}, chapter = {37}, doi = {https://doi.org/10.1016/j.actamat.2016.10.055}, url = {https://www.sciencedirect.com/science/article/pii/S1359645416308229}, author = {Echlin, MP and Titus, MS and Gumbsch, P and Pollock, TM} } @article {1221, title = {Measurement of Strain Localization Resulting from Monotonic and Cyclic Loading at 650 oC in Nickel Base Superalloys}, journal = {Experimental Mechanics}, volume = {57}, year = {2017}, pages = {1289{\textendash}1309}, doi = {10.1007/s11340-017-0286-y}, author = {Stinville, J. C. and Echlin, M. P. and Callahan, P. G. and Miller, V. M. and Texier, D. and Bridier, F. and Bocher, P. and Pollock, T. M.} } @article {1236, title = {Microstructural Statistics for Fatigue Crack Initiation in Polycrystalline Nickel-base Superalloys}, journal = {International Journal of Fracture}, volume = {208}, year = {2017}, pages = {240}, chapter = {221}, doi = {https://doi.org/10.1007/s10704-017-0241-z}, url = {https://link.springer.com/article/10.1007/s10704-017-0241-z}, author = {Stinville, JC and Lenthe, William C and Echlin, MP and Callahan, PG and Texier, Damien and Pollock, TM} } @article {1256, title = {Modelling the elastic properties of bi-continuous composite microstructures captured with TriBeam serial-sectioning}, journal = {Computational Materials Science}, volume = {131}, year = {2017}, pages = {187{\textendash}195}, doi = {10.1016/j.commatsci.2017.01.026}, author = {Mignone, Paul J. and Echlin, Mclean P. and Pollock, Tresa M. and Finlayson, Trevor R. and Riley, Daniel P. and Sesso, Mitchell L. and Franks, George V.} } @article {1226, title = {Oxygen evolution on Fe-doped NiO electrocatalysts deposited via microplasma}, journal = {Nanoscale}, volume = {9}, year = {2017}, pages = {15070{\textendash}15082}, doi = {10.1039/c7nr04302c}, author = {Pebley, Andrew C. and Decolvenaere, Elizabeth and Pollock, Tresa M. and Gordon, Michael J.} } @article {1201, title = {Reconstruction of Laser-Induced Surface Topography from Electron Backscatter Diffraction Patterns}, journal = {Microscopy and Microanalysis}, volume = {23}, year = {2017}, pages = {730{\textendash}740}, doi = {10.1017/s1431927617012326}, author = {Callahan, Patrick G. and Echlin, Mclean P. and Pollock, Tresa M. and Graef, Marc De} } @article {1251, title = {A robust method to characterize rumpling in high-strength bond coats}, journal = {Surface and Coatings Technology}, volume = {317}, year = {2017}, pages = {148{\textendash}157}, doi = {10.1016/j.surfcoat.2017.03.054}, author = {Jorgensen, David J. and Jackson, R. Wesley and Pollock, Tresa M.} } @article {1246, title = {Segmentation-free image processing and analysis of precipitate shapes in 2D and 3D}, journal = {Modelling and Simulation in Materials Science and Engineering}, volume = {25}, year = {2017}, pages = {045009}, doi = {10.1088/1361-651x/aa67b9}, author = {Bales, Ben and Pollock, Tresa and Petzold, Linda} } @article {1196, title = {On Slip Initiation in Equiaxed Alpha/Beta Ti-6Al-4V}, journal = {Acta Materialia}, volume = {136}, year = {2017}, chapter = {288}, doi = {https://doi.org/10.1016/j.actamat.2017.06.059}, url = {https://www.sciencedirect.com/science/article/pii/S1359645417305360?via\%3Dihub}, author = {Kasemer, M and Echlin, MP and Stinville, JC and Pollock, TM and Dawson, P} } @article {1191, title = {Strain fields induced by kink band propagation in Cu-Nb nanolaminate composites}, journal = {Acta Materialia}, volume = {133}, year = {2017}, pages = {303{\textendash}315}, doi = {10.1016/j.actamat.2017.04.050}, author = {Nizolek, T.j. and Begley, MR and McCabe, RJ and Avallone, JT and Mara, NA and Beyerlein, IJ and Pollock, TM} } @article {1181, title = {Thermoelectric performance and the role of anti-site disorder in the 24-electron Heusler TiFe2Sn}, journal = {Journal of Physics: Condensed Matter}, volume = {29}, year = {2017}, month = {Apr}, pages = {405702}, doi = {10.1088/1361-648x/aa81e7}, author = {Buffon, Malinda L C and Laurita, Geneva and Lamontagne, Leo and Levin, Emily E and Mooraj, Shahryar and Lloyd, Demetrious L and White, Natalie and Pollock, Tresa M and Seshadri, Ram} } @article {1241, title = {Three-dimensional texture visualization approaches: theoretical analysis and examples}, journal = {Journal of Applied Crystallography}, volume = {50}, year = {2017}, month = {Jul}, pages = {430{\textendash}440}, doi = {10.1107/s1600576717001157}, author = {Callahan, Patrick G. and Echlin, Mclean and Pollock, Tresa M. and Singh, Saransh and Graef, Marc De} } @article {1186, title = {Tuning the magnetocaloric response in half-Heusler/Heusler MnNi1 xSb solid solutions}, journal = {Physical Review Materials}, volume = {1}, year = {2017}, doi = {10.1103/physrevmaterials.1.075003}, author = {Levin, Emily E. and Bocarsly, Joshua D. and Wyckoff, Kira E. and Pollock, Tresa M. and Seshadri, Ram} } @article {pollock2016alloy, title = {Alloy design for aircraft engines}, journal = {Nature Materials}, volume = {15}, number = {8}, year = {2016}, pages = {809{\textendash}815}, publisher = {Nature Research}, author = {Pollock, Tresa M} } @article {jorgensen2016bond, title = {Bond coatings with high rumpling resistance: Design and characterization}, journal = {Surface and Coatings Technology}, volume = {300}, year = {2016}, pages = {25{\textendash}34}, publisher = {Elsevier}, author = {Jorgensen, David J and Suzuki, Akane and Lipkin, Don M and Pollock, Tresa M} } @article {stinville2016combined, title = {A combined grain scale elastic{\textendash}plastic criterion for identification of fatigue crack initiation sites in a twin containing polycrystalline nickel-base superalloy}, journal = {Acta Materialia}, volume = {103}, year = {2016}, pages = {461{\textendash}473}, publisher = {Pergamon}, author = {Stinville, JC and Lenthe, WC and Miao, J and Pollock, TM} } @article {rettberg2016detecting, title = {Detecting Recrystallization in a Single Crystal Ni-Base Alloy using Resonant Ultrasound Spectroscopy}, journal = {NDT \& E International}, year = {2016}, publisher = {Elsevier}, author = {Rettberg, LH and Goodlet, BR and Pollock, TM} } @article {buffon2016enhancement, title = {Enhancement of thermoelectric properties in the Nb{\textendash}Co{\textendash}Sn half-Heusler/Heusler system through spontaneous inclusion of a coherent second phase}, journal = {Journal of Applied Physics}, volume = {120}, number = {7}, year = {2016}, pages = {075104}, publisher = {AIP Publishing}, author = {Buffon, Malinda LC and Laurita, Geneva and Verma, Nisha and Lamontagne, Leo and Ghadbeigi, Leila and Lloyd, Demetrious L and Sparks, Taylor D and Pollock, Tresa M and Seshadri, Ram} } @article {pebley2016exchange, title = {Exchange bias and spin glass behavior in biphasic NiFe 2 O 4/NiO thin films}, journal = {Journal of Magnetism and Magnetic Materials}, year = {2016}, publisher = {North-Holland}, author = {Pebley, Andrew C and Fuks, Preston E and Pollock, Tresa M and Gordon, Michael J} } @article {echlin2016femtosecond, title = {Femtosecond Laser Damage in Metals and Semiconductors During TriBeam Tomography}, journal = {Microsc. Microanal}, volume = {22}, year = {2016}, pages = {3}, author = {Echlin, MP and Titus, M and Lenthe, WC and Straw, M and Gumbsch, P and Pollock, TM and Fraunhofer, IWM} } @article {rettberg2016growth, title = {Growth Stresses in Thermally Grown Oxides on Nickel-Based Single-Crystal Alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {47}, number = {3}, year = {2016}, pages = {1132{\textendash}1142}, publisher = {Springer US}, author = {Rettberg, Luke H and Laux, Britta and He, Ming Y and Hovis, David and Heuer, Arthur H and Pollock, Tresa M} } @article {echlin2016incipient, title = {Incipient slip and long range plastic strain localization in microtextured Ti-6Al-4V titanium}, journal = {Acta Materialia}, volume = {114}, year = {2016}, pages = {164{\textendash}175}, publisher = {Pergamon}, author = {Echlin, McLean P and Stinville, Jean Charles and Miller, Victoria M and Lenthe, William C and Pollock, Tresa M} } @article {shishvan2016interfacial, title = {Interfacial diffusion in high-temperature deformation of composites: a discrete dislocation plasticity investigation}, journal = {Journal of the Mechanics and Physics of Solids}, year = {2016}, publisher = {Pergamon}, author = {Shishvan, Siamak S and Pollock, Tresa M and McMeeking, Robert M and Deshpande, Vikram S} } @article {douglas2016magnetic, title = {Magnetic hardening and antiferromagnetic/ferromagnetic phase coexistence in Mn 1- x Fe x Ru 2 Sn Heusler solid solutions}, journal = {Physical Review B}, volume = {94}, number = {9}, year = {2016}, pages = {094412}, publisher = {American Physical Society}, author = {Douglas, Jason E and Levin, Emily E and Pollock, Tresa M and Castillo, Juan C and Adler, Peter and Felser, Claudia and Kr{\"a}mer, Stephan and Page, Katharine L and Seshadri, Ram} } @article {texier2016microstructural, title = {Microstructural features controlling the variability in low-cycle fatigue properties of alloy Inconel 718DA at intermediate temperature}, journal = {Metallurgical and Materials Transactions A}, volume = {47}, number = {3}, year = {2016}, pages = {1096{\textendash}1109}, publisher = {Springer US}, author = {Texier, Damien and G{\'o}mez, Ana Casanova and Pierret, St{\'e}phane and Franchet, Jean-Michel and Pollock, Tresa M and Villechaise, Patrick and Cormier, Jonathan} } @article {berman2016microstructure, title = {Microstructure and Texture Through Thixomolding and Thermomechanical Processing and the Role of Mg17Al12 Particles}, journal = {Metallurgical and Materials Transactions A}, volume = {47}, number = {6}, year = {2016}, pages = {3125{\textendash}3136}, publisher = {Springer US}, author = {Berman, Tracy D and Pollock, Tresa M and Jones, J Wayne} } @article {verma2016microstructure, title = {Microstructure Evolution of Biphasic TiNi1+ x Sn Thermoelectric Materials}, journal = {Metallurgical and Materials Transactions A}, year = {2016}, pages = {1{\textendash}12}, publisher = {Springer US}, author = {Verma, Nisha and Douglas, Jason E and Kr{\"a}mer, Stephan and Pollock, Tresa M and Seshadri, Ram and Levi, Carlos G} } @article {eggeler2016planar, title = {Planar defect formation in the g' phase during high temperature creep in single crystal CoNi-base superalloys}, journal = {Acta Materialia}, volume = {113}, year = {2016}, pages = {335{\textendash}349}, publisher = {Pergamon}, author = {Eggeler, YM and M{\"u}ller, J and Titus, MS and Suzuki, A and Pollock, TM and Spiecker, E} } @article {lenthe2016prediction, title = {Prediction of Fatigue-Initiating Twin Boundaries in Polycrystalline Nickel Superalloys Informed by TriBeam Tomography}, journal = {Microscopy and Microanalysis}, volume = {22}, number = {S3}, year = {2016}, pages = {1732{\textendash}1733}, publisher = {Cambridge University Press}, author = {Lenthe, William C and Stinville, Jean-Charles and Echlin, McLean P and Pollock, Tresa M} } @article {miller2016prediction, title = {Prediction of Magnesium Alloy Formability: The Role of Texture}, journal = {Magnesium Technology 2016}, year = {2016}, pages = {257{\textendash}262}, publisher = {John Wiley \& Sons, Inc.}, author = {Miller, VM and Berman, TD and Beyerlein, IJ and Pollock, TM} } @article {miller2016prediction, title = {Prediction of the plastic anisotropy of magnesium alloys with synthetic textures and implications for the effect of texture on formability}, journal = {Materials Science and Engineering: A}, volume = {675}, year = {2016}, pages = {345{\textendash}360}, publisher = {Elsevier}, author = {Miller, Victoria M and Berman, Tracy D and Beyerlein, Irene J and Jones, J Wayne and Pollock, Tresa M} } @article {miller2016recrystallization, title = {Recrystallization and the Development of Abnormally Large Grains After Small Strain Deformation in a Polycrystalline Nickel-Based Superalloy}, journal = {Metallurgical and Materials Transactions A}, volume = {47}, number = {4}, year = {2016}, pages = {1566{\textendash}1574}, publisher = {Springer US}, author = {Miller, Victoria M and Johnson, Anthony E and Torbet, Chris J and Pollock, Tresa M} } @article {meher2016solute, title = {Solute partitioning in multi-component $\gamma$/$\gamma$' Co{\textendash}Ni-base superalloys with near-zero lattice misfit}, journal = {Scripta Materialia}, volume = {113}, year = {2016}, pages = {185{\textendash}189}, publisher = {Pergamon}, author = {Meher, S and Carroll, LJ and Pollock, TM and Carroll, MC} } @article {stinville2016sub, title = {Sub-grain scale digital image correlation by electron microscopy for polycrystalline materials during elastic and plastic deformation}, journal = {Experimental Mechanics}, volume = {56}, number = {2}, year = {2016}, pages = {197{\textendash}216}, publisher = {Springer US}, author = {Stinville, JC and Echlin, MP and Texier, D and Bridier, F and Bocher, P and Pollock, TM} } @article {nizolek2016tensile, title = {Tensile behavior and flow stress anisotropy of accumulative roll bonded Cu-Nb nanolaminates}, journal = {Applied Physics Letters}, volume = {108}, number = {5}, year = {2016}, pages = {051903}, publisher = {AIP Publishing}, author = {Nizolek, Thomas and Beyerlein, Irene J and Mara, Nathan A and Avallone, Jaclyn T and Pollock, Tresa M} } @article {miller2016texture, title = {Texture Modification in a Magnesium-Aluminum-Calcium Alloy During Uniaxial Compression}, journal = {Metallurgical and Materials Transactions A}, volume = {47}, number = {4}, year = {2016}, pages = {1854{\textendash}1864}, publisher = {Springer US}, author = {Miller, Victoria M and Pollock, Tresa M} } @article {jackson2016thermal, title = {Thermal expansion behavior of new Co-based alloys and implications for coatings}, journal = {Surface and Coatings Technology}, volume = {289}, year = {2016}, pages = {61{\textendash}68}, publisher = {Elsevier}, author = {Jackson, R Wesley and Titus, Michael S and Begley, Matthew R and Pollock, Tresa M} } @article {meher2016understanding, title = {Understanding of Inverse Coarsening of $\gamma${\textquoteright}precipitates in Ni-base Superalloys}, journal = {Microscopy and Microanalysis}, volume = {22}, number = {S3}, year = {2016}, pages = {1258{\textendash}1259}, publisher = {Cambridge University Press}, author = {Meher, Subhashish and Aagesen, Larry K and Carroll, Laura J and Carroll, Mark C and Pollock, Tresa M} } @article {steuer2015benefits, title = {Benefits of high gradient solidification for creep and low cycle fatigue of AM1 single crystal superalloy}, journal = {Materials Science and Engineering: A}, volume = {645}, year = {2015}, pages = {109{\textendash}115}, publisher = {Elsevier}, author = {Steuer, S and Villechaise, P and Pollock, TM and Cormier, J} } @article {carpenter2015bulk, title = {Bulk texture evolution of nanolamellar Zr{\textendash}Nb composites processed via accumulative roll bonding}, journal = {Acta Materialia}, volume = {92}, year = {2015}, pages = {97{\textendash}108}, publisher = {Pergamon}, author = {Carpenter, JS and Nizolek, T and McCabe, RJ and Knezevic, M and Zheng, SJ and Eftink, BP and Scott, JE and Vogel, SC and Pollock, TM and Mara, NA and others} } @article {titus2015creep, title = {Creep-induced planar defects in L1 2-containing Co-and CoNi-base single-crystal superalloys}, journal = {Acta Materialia}, volume = {82}, year = {2015}, pages = {530{\textendash}539}, publisher = {Pergamon}, author = {Titus, Michael S and Eggeler, Yolita M and Suzuki, Akane and Pollock, Tresa M} } @article {callahan2015determination, title = {Determination of Surface Topography from Laser Ablation using EBSD}, journal = {Microscopy and Microanalysis}, volume = {21}, number = {S3}, year = {2015}, pages = {2369{\textendash}2370}, publisher = {Cambridge University Press}, author = {Callahan, PG and Echlin, MP and Pollock, TM and De Graef, M} } @article {titus2015dislocation, title = {Dislocation injection in strontium titanate by femtosecond laser pulses}, journal = {Journal of Applied Physics}, volume = {118}, number = {7}, year = {2015}, pages = {075901}, publisher = {AIP Publishing}, author = {Titus, Michael S and Echlin, McLean P and Gumbsch, Peter and Pollock, Tresa M} } @article {jorgensen2015dynamic, title = {Dynamic response of thin films on substrates subjected to femtosecond laser pulses}, journal = {Acta Materialia}, volume = {84}, year = {2015}, pages = {136{\textendash}144}, publisher = {Pergamon}, author = {Jorgensen, David J and Pollock, Tresa M and Begley, Matthew R} } @article {nizolek2015enhanced, title = {Enhanced plasticity via kinking in cubic metallic nanolaminates}, journal = {Advanced Engineering Materials}, volume = {17}, number = {6}, year = {2015}, pages = {781{\textendash}785}, author = {Nizolek, Thomas and Mara, Nathan A and Beyerlein, Irene J and Avallone, Jaclyn T and Pollock, Tresa M} } @article {jorgensen2015femtosecond, title = {Femtosecond laser ablation and nanoparticle formation in intermetallic NiAl}, journal = {Applied Surface Science}, volume = {353}, year = {2015}, pages = {700{\textendash}707}, publisher = {North-Holland}, author = {Jorgensen, David J and Titus, Michael S and Pollock, Tresa M} } @article {titus2015high, title = {High resolution energy dispersive spectroscopy mapping of planar defects in L1 2-containing co-base superalloys}, journal = {Acta Materialia}, volume = {89}, year = {2015}, pages = {423{\textendash}437}, publisher = {Pergamon}, author = {Titus, Michael S and Mottura, Alessandro and Viswanathan, G Babu and Suzuki, Akane and Mills, Michael J and Pollock, Tresa M} } @article {stinville2015high, title = {High resolution mapping of strain localization near twin boundaries in a nickel-based superalloy}, journal = {Acta Materialia}, volume = {98}, year = {2015}, pages = {29{\textendash}42}, publisher = {Pergamon}, author = {Stinville, JC and Vanderesse, N and Bridier, F and Bocher, P and Pollock, TM} } @booklet {nizolek2015high, title = {High strength bulk metallic nanolaminates}, year = {2015}, publisher = {ASM INT SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA}, author = {Nizolek, Thomas and Avallone, Jaclyn and Pollock, Tresa and Mara, Nathan and Beyerlein, Irene and Scott, Jeffrey} } @article {echlin2015situ, title = {In situ Femtosecond Laser and Argon Ion Beams for 3D Microanalysis using the TriBeam}, journal = {Microscopy and Microanalysis}, volume = {21}, number = {S3}, year = {2015}, pages = {1847{\textendash}1848}, publisher = {Cambridge University Press}, author = {Echlin, MP and Lenthe, WC and Douglas, J and Titus, M and Guerts, R and Straw, M and Pollock, TM} } @article {nizolek2015kink, title = {Kink band formation in high-strength bulk metallic nanolaminates}, journal = {Microscopy and Microanalysis}, volume = {21}, number = {S3}, year = {2015}, pages = {1157{\textendash}1158}, publisher = {Cambridge University Press}, author = {Nizolek, T and Mara, NA and McCabe, RJ and Avallone, JT and Beyerlein, IJ and Pollock, TM} } @article {suzuki2015l12, title = {L12-Strengthened Cobalt-Base Superalloys}, journal = {Annual Review of Materials Research}, volume = {45}, year = {2015}, pages = {345{\textendash}368}, publisher = {Annual Reviews}, author = {Suzuki, Akane and Inui, Haruyuki and Pollock, Tresa M} } @article {van2015pt, title = {A Pt-modified Ni-base superalloy with high temperature precipitate stability}, journal = {Materials Science and Engineering: A}, volume = {639}, year = {2015}, pages = {747{\textendash}754}, publisher = {Elsevier}, author = {Van Sluytman, Jason S and Moceri, Charles J and Pollock, Tresa M} } @article {lenthe2015quantitative, title = {Quantitative Analysis of Correlated 3D Strontium Titanate Datasets Collected by TriBeam and Diffraction Contrast Tomography}, journal = {Microscopy and Microanalysis}, volume = {21}, number = {S3}, year = {2015}, pages = {2043{\textendash}2044}, publisher = {Cambridge University Press}, author = {Lenthe, WC and Echlin, MP and Syha, M and Trenkle, A and Gumbsch, P and Pollock, TM} } @article {lenthe2015quantitative, title = {Quantitative voxel-to-voxel comparison of TriBeam and DCT strontium titanate three-dimensional data sets}, journal = {Journal of Applied Crystallography}, volume = {48}, number = {4}, year = {2015}, pages = {1034{\textendash}1046}, publisher = {International Union of Crystallography}, author = {Lenthe, William C and Echlin, MP and Trenkle, Andreas and Syha, Melanie and Gumbsch, Peter and Pollock, Tresa M} } @conference {biedermann2015resonance, title = {Resonance ultrasound spectroscopy forward modeling and inverse characterization of nickel-based superalloys}, booktitle = {41ST ANNUAL REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION: Volume 34}, volume = {1650}, number = {1}, year = {2015}, pages = {835{\textendash}844}, publisher = {AIP Publishing}, organization = {AIP Publishing}, author = {Biedermann, Eric and Jauriqui, Leanne and Aldrin, John C and Goodlet, Brent and Pollock, Tresa and Torbet, Chris and Mazdiyasni, Siamack} } @article {rhein2015role, title = {Role of vibrational and configurational excitations in stabilizing the L 1 2 structure in Co-rich Co-Al-W alloys}, journal = {Physical Review B}, volume = {92}, number = {17}, year = {2015}, pages = {174117}, publisher = {American Physical Society}, author = {Rhein, Robert K and Dodge, Philip C and Chen, Min-Hua and Titus, Michael S and Pollock, Tresa M and Van der Ven, Anton} } @article {theillard2015sharp, title = {A sharp computational method for the simulation of the solidification of binary alloys}, journal = {Journal of Scientific Computing}, volume = {63}, number = {2}, year = {2015}, pages = {330{\textendash}354}, publisher = {Springer US}, author = {Theillard, Maxime and Gibou, Fr{\'e}d{\'e}ric and Pollock, Tresa} } @article {ardeljan2015study, title = {A study of microstructure-driven strain localizations in two-phase polycrystalline HCP/BCC composites using a multi-scale model}, journal = {International Journal of Plasticity}, volume = {74}, year = {2015}, pages = {35{\textendash}57}, publisher = {Pergamon}, author = {Ardeljan, Milan and Knezevic, Marko and Nizolek, Thomas and Beyerlein, Irene J and Mara, Nathan A and Pollock, Tresa M} } @article {carpenter2015suppression, title = {The suppression of instabilities via biphase interfaces during bulk fabrication of nanograined Zr}, journal = {Materials Research Letters}, volume = {3}, number = {1}, year = {2015}, pages = {50{\textendash}57}, publisher = {Taylor \& Francis}, author = {Carpenter, JS and Nizolek, TJ and McCabe, RJ and Zheng, SJ and Scott, JE and Vogel, SC and Mara, NA and Pollock, TM and Beyerlein, IJ} } @article {berman2015texture, title = {Texture, Second-Phase Particles, and the Anisotropy of Deformation Behavior in TTMP AZ61}, journal = {Metallurgical and Materials Transactions A}, volume = {46}, number = {7}, year = {2015}, pages = {2986{\textendash}2998}, publisher = {Springer US}, author = {Berman, Tracy D and Pollock, Tresa M and Jones, J Wayne} } @article {douglas2015three, title = {Three-dimensional multimodal imaging and analysis of biphasic microstructure in a Ti{\textendash}Ni{\textendash}Sn thermoelectric material}, journal = {APL Materials}, volume = {3}, number = {9}, year = {2015}, pages = {096107}, publisher = {AIP Publishing}, author = {Douglas, Jason E and Echlin, McLean P and Lenthe, William C and Seshadri, Ram and Pollock, Tresa M} } @article {stinville2015transverse, title = {Transverse creep of nickel-base superalloy bicrystals}, journal = {Metallurgical and Materials Transactions A}, volume = {46}, number = {6}, year = {2015}, pages = {2516{\textendash}2529}, publisher = {Springer US}, author = {Stinville, JC and Gallup, K and Pollock, TM} } @article {echlin2015tribeam, title = {The TriBeam system: Femtosecond laser ablation in situ SEM}, journal = {Materials Characterization}, volume = {100}, year = {2015}, pages = {1{\textendash}12}, publisher = {Elsevier}, author = {Echlin, McLean P and Straw, Marcus and Randolph, Steven and Filevich, Jorge and Pollock, Tresa M} } @article {adharapurapu2014combinatorial, title = {A combinatorial investigation of palladium and platinum additions to $\beta$-NiAl overlay coatings}, journal = {Acta Materialia}, volume = {77}, year = {2014}, pages = {379{\textendash}393}, publisher = {Pergamon}, author = {Adharapurapu, Raghavendra R and Zhu, Jun and Dheeradhada, Voramon S and Lipkin, Don M and Pollock, Tresa M} } @article {steuer2014creep, title = {Creep behavior under isothermal and non-isothermal conditions of AM3 single crystal superalloy for different solutioning cooling rates}, journal = {Materials Science and Engineering: A}, volume = {601}, year = {2014}, pages = {145{\textendash}152}, publisher = {Elsevier}, author = {Steuer, S and Hervier, Z and Thabart, S and Castaing, C and Pollock, TM and Cormier, J} } @article {eggeler2014creep, title = {Creep deformation-induced antiphase boundaries in L1 2-containing single-crystal cobalt-base superalloys}, journal = {Acta Materialia}, volume = {77}, year = {2014}, pages = {352{\textendash}359}, publisher = {Pergamon}, author = {Eggeler, Yolita M and Titus, Michael S and Suzuki, Akane and Pollock, Tresa M} } @article {pollock2014design, title = {Design constraints and higher temperature intermetallic bond coatings}, year = {2014}, author = {Pollock, TM and Jorgensen, D and Jackson, RW and He, M and Suzuki, A and Lipkin, D} } @article {berman2014effect, title = {Effect of Microstructure on Deformation and Fracture of Thixomolded and Thermomechanically Processed AZ61}, journal = {Magnesium Technology 2014}, year = {2014}, pages = {161{\textendash}166}, publisher = {John Wiley \& Sons, Inc.}, author = {Berman, TD and Donlon, W and Decker, R and Pollock, TM and Jones, JW} } @article {miller2014effect, title = {The effect of processing conditions on heat transfer during directional solidification via the Bridgman and liquid metal cooling processes}, journal = {Metallurgical and materials transactions A}, volume = {45}, number = {1}, year = {2014}, pages = {411{\textendash}425}, publisher = {Springer US}, author = {Miller, Jonathan D and Pollock, Tresa M} } @article {adharapurapu2014effective, title = {Effective Hf-Pd Co-doped $\beta$-NiAl (Cr) coatings for single-crystal superalloys}, journal = {Acta Materialia}, volume = {76}, year = {2014}, pages = {449{\textendash}462}, publisher = {Pergamon}, author = {Adharapurapu, Raghavendra R and Zhu, Jun and Dheeradhada, Voramon S and Lipkin, Don M and Pollock, Tresa M} } @article {handwerker2014emerging, title = {Emerging science and research opportunities for metals and metallic nanostructures}, journal = {Jom}, volume = {66}, number = {7}, year = {2014}, pages = {1321{\textendash}1341}, publisher = {Springer US}, author = {Handwerker, Carol A and Pollock, Tresa M} } @article {iyer2014energetics, title = {Energetics and nucleation of point defects in aluminum under extreme tensile hydrostatic stresses}, journal = {Physical Review B}, volume = {89}, number = {1}, year = {2014}, pages = {014108}, publisher = {American Physical Society}, author = {Iyer, Mrinal and Gavini, Vikram and Pollock, Tresa M} } @article {zhu2014experimental, title = {Experimental investigation and thermodynamic modeling of the Co-rich region in the Co-Al-Ni-W quaternary system}, journal = {Journal of Phase Equilibria and Diffusion}, volume = {35}, number = {5}, year = {2014}, pages = {595{\textendash}611}, publisher = {Springer US}, author = {Zhu, J and Titus, MS and Pollock, TM} } @article {rettberg2014localized, title = {Localized recrystallization during creep in nickel-based superalloys GTD444 and Ren{\'e} N5}, journal = {Acta Materialia}, volume = {73}, year = {2014}, pages = {287{\textendash}297}, publisher = {Pergamon}, author = {Rettberg, LH and Pollock, TM} } @article {pebley2014microplasma, title = {Microplasma-Based Growth of Biphasic NiFe2O4/NiO Nanogranular Films for Exchange Bias Applications}, journal = {Chemistry of Materials}, volume = {26}, number = {20}, year = {2014}, pages = {6026{\textendash}6032}, publisher = {American Chemical Society}, author = {Pebley, Andrew C and Peek, Alex and Pollock, Tresa M and Gordon, Michael J} } @conference {ardeljan2014multi, title = {A multi-scale model for texture development in Zr/Nb nanolayered composites processed by accumulative roll bonding}, booktitle = {IOP Conference Series: Materials Science and Engineering}, volume = {63}, number = {1}, year = {2014}, pages = {012170}, publisher = {IOP Publishing}, organization = {IOP Publishing}, author = {Ardeljan, M and Knezevic, M and Nizolek, T and Beyerlein, IJ and Zheng, SJ and Carpenter, JS and McCabe, RJ and Mara, NA and Pollock, TM} } @article {douglas2014nanoscale, title = {Nanoscale structural heterogeneity in Ni-rich half-Heusler TiNiSn}, journal = {Journal of Applied Physics}, volume = {116}, number = {16}, year = {2014}, pages = {163514}, publisher = {AIP Publishing}, author = {Douglas, Jason E and Chater, Philip A and Brown, Craig M and Pollock, Tresa M and Seshadri, Ram} } @conference {suzuki2014oxide, title = {Oxide-assisted crack growth in hold-time low-cycle-fatigue of single-crystal superalloys}, booktitle = {MATEC Web of Conferences}, volume = {14}, year = {2014}, pages = {04004}, publisher = {EDP Sciences}, organization = {EDP Sciences}, author = {Suzuki, Akane and Gao, Yan and Lipkin, Don and Singhal, Anjali and Krug, Matthew and Konitzer, Douglas and Almer, Jonathan and Pollock, Tresa and Bewlay, Bernard} } @article {douglas2014phase, title = {Phase stability and property evolution of biphasic Ti{\textendash}Ni{\textendash}Sn alloys for use in thermoelectric applications}, journal = {Journal of Applied Physics}, volume = {115}, number = {4}, year = {2014}, pages = {043720}, publisher = {AIP Publishing}, author = {Douglas, Jason E and Birkel, Christina S and Verma, Nisha and Miller, Victoria M and Miao, Mao-Sheng and Stucky, Galen D and Pollock, Tresa M and Seshadri, Ram} } @article {nizolek2014processing, title = {Processing and deformation behavior of bulk Cu{\textendash}Nb nanolaminates}, journal = {Metallography, Microstructure, and Analysis}, volume = {3}, number = {6}, year = {2014}, pages = {470{\textendash}476}, publisher = {Springer US}, author = {Nizolek, T and Mara, NA and Beyerlein, IJ and Avallone, JT and Scott, JE and Pollock, TM} } @article {miller2014simulation, title = {Simulation of diffusion-limited lateral growth of dendrites during solidification via liquid metal cooling}, journal = {Acta Materialia}, volume = {69}, year = {2014}, pages = {47{\textendash}59}, publisher = {Pergamon}, author = {Miller, JD and Yuan, L and Lee, PD and Pollock, TM} } @article {miller2014stability, title = {Stability of dendrite growth during directional solidification in the presence of a non-axial thermal field}, journal = {Acta Materialia}, volume = {78}, year = {2014}, pages = {23{\textendash}36}, publisher = {Pergamon}, author = {Miller, JD and Pollock, TM} } @article {titus2014sub, title = {Sub-nanometer Resolution Chemi-STEM EDS Mapping of Superlattice Intrinsic Stacking Faults in Co-based Superalloys}, journal = {Microscopy and Microanalysis}, volume = {20}, number = {S3}, year = {2014}, pages = {1028{\textendash}1029}, publisher = {Cambridge University Press}, author = {Titus, Michael S and Suzuki, Akane and Mills, Michael J and Pollock, Tresa M} } @article {knezevic2014texture, title = {Texture evolution in two-phase Zr/Nb lamellar composites during accumulative roll bonding}, journal = {International Journal of Plasticity}, volume = {57}, year = {2014}, pages = {16{\textendash}28}, publisher = {Pergamon}, author = {Knezevic, Marko and Nizolek, Thomas and Ardeljan, Milan and Beyerlein, Irene J and Mara, Nathan A and Pollock, Tresa M} } @article {jackson2014thermal, title = {Thermal barrier coating adherence to Hf-modified B2 NiAl bond coatings}, journal = {Acta Materialia}, volume = {80}, year = {2014}, pages = {39{\textendash}47}, publisher = {Pergamon}, author = {Jackson, RW and Lipkin, DM and Pollock, TM} } @article {echlin2014three, title = {Three-dimensional characterization of the permeability of W{\textendash}Cu composites using a new {\textquotedblleft}TriBeam{\textquotedblright} technique}, journal = {Acta Materialia}, volume = {64}, year = {2014}, pages = {307{\textendash}315}, publisher = {Pergamon}, author = {Echlin, McLean P and Mottura, Alessandro and Wang, Michael and Mignone, Paul J and Riley, Daniel P and Franks, George V and Pollock, Tresa M} } @article {echlin2014three, title = {Three-dimensional sampling of material structure for property modeling and design}, journal = {Integrating Materials and Manufacturing Innovation}, volume = {3}, number = {1}, year = {2014}, pages = {1}, publisher = {Springer Berlin Heidelberg}, author = {Echlin, McLean P and Lenthe, William C and Pollock, Tresa M} } @article {knezevic2013anomalous, title = {Anomalous basal slip activity in zirconium under high-strain deformation}, journal = {Materials Research Letters}, volume = {1}, number = {3}, year = {2013}, pages = {133{\textendash}140}, publisher = {Taylor \& Francis}, author = {Knezevic, Marko and Beyerlein, Irene J and Nizolek, Thomas and Mara, Nathan A and Pollock, Tresa M} } @article {vermaak2013cyclic, title = {Cyclic oxidation of high temperature coatings on new $\gamma$'-strengthened cobalt-based alloys}, journal = {Corrosion Science}, volume = {75}, year = {2013}, pages = {300{\textendash}308}, publisher = {Pergamon}, author = {Vermaak, N and Mottura, A and Pollock, TM} } @article {echlin2013ebsd, title = {EBSD Imaging of Femtosecond Laser Ablated Surfaces Using the TriBeam System}, journal = {Microscopy and Microanalysis}, volume = {19}, number = {S2}, year = {2013}, pages = {864{\textendash}865}, publisher = {Cambridge Univ Press}, author = {Echlin, MP and Titus, M and Kraemer, S and Pollock, T} } @article {godlewski2013effect, title = {The effect of aging on the relaxation of residual stress in cast aluminum}, journal = {Metallurgical and Materials Transactions A}, volume = {44}, number = {10}, year = {2013}, pages = {4809{\textendash}4818}, publisher = {Springer US}, author = {Godlewski, Larry A and Su, Xuming and Pollock, Tresa M and Allison, John E} } @article {pollock2013feedback, title = {The feedback loop between theory, simulation and experiment for plasticity and property modeling}, journal = {Current Opinion in Solid State and Materials Science}, volume = {17}, number = {1}, year = {2013}, pages = {10{\textendash}18}, publisher = {Elsevier}, author = {Pollock, Tresa M and LeSar, Richard} } @article {pollock2013femtosecond, title = {Femtosecond Laser Tomography Using the TriBeam System}, journal = {Microscopy and Microanalysis}, volume = {19}, number = {S2}, year = {2013}, pages = {698{\textendash}699}, publisher = {Cambridge Univ Press}, author = {Pollock, TM and Echlin, MP and Mottura, A} } @article {birkel2013improving, title = {Improving the thermoelectric properties of half-Heusler TiNiSn through inclusion of a second full-Heusler phase: microwave preparation and spark plasma sintering of TiNi 1+ x Sn}, journal = {Physical Chemistry Chemical Physics}, volume = {15}, number = {18}, year = {2013}, pages = {6990{\textendash}6997}, publisher = {Royal Society of Chemistry}, author = {Birkel, Christina S and Douglas, Jason E and Lettiere, Bethany R and Seward, Gareth and Verma, Nisha and Zhang, Yichi and Pollock, Tresa M and Seshadri, Ram and Stucky, Galen D} } @article {birkel2013influence, title = {Influence of Ni nanoparticle addition and spark plasma sintering on the TiNiSn{\textendash}Ni system: structure, microstructure, and thermoelectric properties}, journal = {Solid State Sciences}, volume = {26}, year = {2013}, pages = {16{\textendash}22}, publisher = {Elsevier Masson}, author = {Birkel, Christina S and Douglas, Jason E and Lettiere, Bethany R and Seward, Gareth and Zhang, Yichi and Pollock, Tresa M and Seshadri, Ram and Stucky, Galen D} } @article {allison2013integrated, title = {Integrated Computational Materials Engineering (ICME): Implementing ICME in the Aerospace, Automotive, and Maritime Industries}, journal = {A Study Organized by The Minerals, Metals \& Materials Society. The Minerals, Metals \& Materials Society, Warrendale, PA}, volume = {15086}, year = {2013}, author = {Allison, John and Cowles, Brad and DeLoach, John and Pollock, Tresa and Spanos, George} } @article {berman2013microstructure, title = {Microstructure Characterization of Weakly Textured and Fine Grained AZ61 Sheet}, journal = {Magnesium Technology 2013}, year = {2013}, pages = {113{\textendash}118}, publisher = {Wiley Online Library}, author = {Berman, TD and Donlon, W and Hung, CK and Milligan, P and Decker, R and Pollock, TM and Jones, JW} } @article {lenaburg2013outcomes, title = {Outcomes from research collaborations: What are they and how long do they take?}, journal = {MRS bulletin}, volume = {38}, number = {07}, year = {2013}, pages = {526{\textendash}528}, publisher = {Cambridge Univ Press}, author = {Lenaburg, Lubella A and Sciaky, Elizabeth S and Pollock, Tresa M} } @article {jackson2013oxidation, title = {The oxidation and rumpling behavior of overlay B2 bond coats containing Pt, Pd, Cr and Hf}, journal = {Surface and Coatings Technology}, volume = {221}, year = {2013}, pages = {13{\textendash}21}, publisher = {Elsevier}, author = {Jackson, RW and Lipkin, DM and Pollock, TM} } @article {miller2013recrystallization, title = {Recrystallization Behavior of a MgAlCa Alloy during Thermomechanical Processing and Subsequent Heat Treatment}, journal = {Magnesium Technology 2013}, year = {2013}, pages = {203{\textendash}209}, publisher = {Wiley Online Library}, author = {Miller, VM and Pollock, TM} } @article {echlin2013statistical, title = {A statistical sampling approach for measurement of fracture toughness parameters in a 4330 steel by 3-D femtosecond laser-based tomography}, journal = {Acta Materialia}, volume = {61}, number = {15}, year = {2013}, pages = {5791{\textendash}5799}, publisher = {Elsevier}, author = {Echlin, McLean P and Pollock, Tresa M} } @article {mottura2012alloying, title = {Alloying Effects in the $\gamma$' Phase of Co-Based Superalloys}, journal = {Superalloys 2012}, year = {2012}, pages = {683{\textendash}693}, publisher = {John Wiley \& Sons, Inc.}, author = {Mottura, Alessandro and Janotti, Anderson and Pollock, Tresa M} } @article {titus2012creep, title = {Creep and directional coarsening in single crystals of new $\gamma${\textendash}$\gamma$' cobalt-base alloys}, journal = {Scripta Materialia}, volume = {66}, number = {8}, year = {2012}, pages = {574{\textendash}577}, publisher = {Elsevier}, author = {Titus, Michael S and Suzuki, Akane and Pollock, Tresa M} } @article {terbush2012dependence, title = {The dependence of creep behavior on elemental partitioning in Mg-5Al-3Ca-xSn alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {43}, number = {9}, year = {2012}, pages = {3120{\textendash}3134}, publisher = {Springer US}, author = {TerBush, Jessica R and Chen, Olivia H and Jones, J Wayne and Pollock, Tresa M} } @article {miller2012development, title = {Development and Application of an Optimization Protocol for Directional Solidification: Integrating Fundamental Theory, Experimentation and Modeling Tools}, journal = {Superalloys 2012}, year = {2012}, pages = {653{\textendash}662}, publisher = {John Wiley \& Sons, Inc.}, author = {Miller, Jonathan D and Pollock, Tresa M} } @article {douglas2012enhanced, title = {Enhanced thermoelectric properties of bulk TiNiSn via formation of a TiNi2Sn second phase}, journal = {Applied Physics Letters}, volume = {101}, number = {18}, year = {2012}, pages = {183902}, publisher = {AIP Publishing}, author = {Douglas, Jason E and Birkel, Christina S and Miao, Mao-Sheng and Torbet, Chris J and Stucky, Galen D and Pollock, Tresa M and Seshadri, Ram} } @conference {mottura2012first, title = {A First Principles Study of the Effect of Ti and Ta on the SFE of the registered{\textquoteright} Phase of Co-based Superalloys}, booktitle = {AIP Conference Proceedings}, year = {2012}, publisher = {American Institute of Physics, Ste. 1 NO 1 Melville NY 11747-4502 United States}, organization = {American Institute of Physics, Ste. 1 NO 1 Melville NY 11747-4502 United States}, author = {Mottura, Alessandro and Janotti, Anderson and Pollock, Tresa} } @article {mottura2012first, title = {A first-principles study of the effect of Ta on the superlattice intrinsic stacking fault energy of L1 2-Co 3 (Al, W)}, journal = {Intermetallics}, volume = {28}, year = {2012}, pages = {138{\textendash}143}, publisher = {Elsevier}, author = {Mottura, Alessandro and Janotti, Anderson and Pollock, Tresa M} } @article {madison2012fluid, title = {Fluid flow and defect formation in the three-dimensional dendritic structure of nickel-based single crystals}, journal = {Metallurgical and Materials Transactions A}, volume = {43}, number = {1}, year = {2012}, pages = {369{\textendash}380}, publisher = {Springer}, author = {Madison, J and Spowart, JE and Rowenhorst, DJ and Aagesen, LK and Thornton, K and Pollock, TM} } @article {titus2012high, title = {High Temperature Creep of New L12 Containing Cobalt-Base Superalloys}, journal = {Superalloys 2012}, year = {2012}, pages = {823{\textendash}832}, publisher = {Wiley Online Library}, author = {Titus, Michael S and Suzuki, Akane and Pollock, Tresa M} } @article {saini2012high, title = {High-temperature materials increase efficiency of gas power plants}, journal = {MRS bulletin}, volume = {37}, number = {06}, year = {2012}, pages = {550{\textendash}551}, publisher = {Cambridge University Press}, author = {Saini, Angela and Pollock, Tresa} } @article {miao2012microstructural, title = {Microstructural extremes and the transition from fatigue crack initiation to small crack growth in a polycrystalline nickel-base superalloy}, journal = {Acta Materialia}, volume = {60}, number = {6}, year = {2012}, pages = {2840{\textendash}2854}, publisher = {Pergamon}, author = {Miao, Jiashi and Pollock, Tresa M and Jones, J Wayne} } @article {berman2012microstructure, title = {Microstructure Modification and Deformation Behavior of Fine-Grained AZ61 Sheet Produced by Thixomolding and Thermomechanical Processing (TTMP)}, journal = {Magnesium Technology 2012}, year = {2012}, pages = {339{\textendash}344}, publisher = {John Wiley \& Sons, Inc.}, author = {Berman, TD and Donlon, William and Miller, VM and Decker, R and Huang, J and Pollock, TM and Jones, JW} } @article {pollock2012multifunctional, title = {Multifunctional coating interlayers for thermal-barrier systems}, journal = {MRS bulletin}, volume = {37}, number = {10}, year = {2012}, pages = {923{\textendash}931}, publisher = {Cambridge Univ Press}, author = {Pollock, TM and Lipkin, DM and Hemker, KJ} } @article {echlin2012new, title = {A new TriBeam system for three-dimensional multimodal materials analysis}, journal = {Review of Scientific Instruments}, volume = {83}, number = {2}, year = {2012}, pages = {023701}, publisher = {AIP Publishing}, author = {Echlin, McLean P and Mottura, Alessandro and Torbet, Christopher J and Pollock, Tresa M} } @article {van2012optimal, title = {Optimal precipitate shapes in nickel-base $\gamma${\textendash}$\gamma$' alloys}, journal = {Acta Materialia}, volume = {60}, number = {4}, year = {2012}, pages = {1771{\textendash}1783}, publisher = {Elsevier}, author = {Van Sluytman, JS and Pollock, TM} } @article {miller2012process, title = {Process Simulation for the Directional Solidification of a Tri-Crystal Ring Segment via the Bridgman and Liquid-Metal-Cooling Processes}, journal = {Metallurgical and Materials Transactions A}, volume = {43}, number = {7}, year = {2012}, pages = {2414{\textendash}2425}, publisher = {Springer}, author = {Miller, JD and Pollock, TM} } @article {brundidge2012processing, title = {Processing to fatigue properties: benefits of high gradient casting for single crystal airfoils}, journal = {Superalloys 2012}, year = {2012}, pages = {379{\textendash}385}, publisher = {John Wiley \& Sons, Inc.}, author = {Brundidge, Clinique L and Pollock, Tresa M} } @article {rettberg2012rejuvenation, title = {Rejuvenation of Nickel-Based Superalloys GTD444 (DS) and Ren{\'e} N5 (SX)}, journal = {Superalloys 2012}, year = {2012}, pages = {341{\textendash}349}, publisher = {John Wiley \& Sons, Inc.}, author = {Rettberg, LH and Tsunekane, M and Pollock, TM} } @conference {berman2012structure, title = {Structure Evolution in AZ 61 L along a Fine-Grain Sheet Processing Path}, booktitle = {AIP Conference Proceedings}, year = {2012}, publisher = {American Institute of Physics, Ste. 1 NO 1 Melville NY 11747-4502 United States}, organization = {American Institute of Physics, Ste. 1 NO 1 Melville NY 11747-4502 United States}, author = {Berman, Tracy and Donlon, William and Miller, Victoria and Huang, Jack and Decker, Ray and Jones, Wayne and Pollock, Tresa} } @article {brundidge2012structure, title = {Structure refinement by a liquid metal cooling solidification process for single-crystal nickel-base superalloys}, journal = {Metallurgical and Materials Transactions A}, volume = {43}, number = {3}, year = {2012}, pages = {965{\textendash}976}, publisher = {Springer US}, author = {Brundidge, CL and Van Drasek, D and Wang, B and Pollock, TM} } @article {beyerlein2012structure, title = {Structure{\textendash}property{\textendash}functionality of bimetal interfaces}, journal = {Jom}, volume = {64}, number = {10}, year = {2012}, pages = {1192{\textendash}1207}, publisher = {Springer US}, author = {Beyerlein, IJ and Mara, NA and Wang, J and Carpenter, JS and Zheng, SJ and Han, WZ and Zhang, RF and Kang, K and Nizolek, T and Pollock, TM} } @conference {gallup2012transverse, title = {Transverse Creep Behavior of Superalloy Bicrystals}, booktitle = {AIP Conference Proceedings}, year = {2012}, publisher = {American Institute of Physics, Ste. 1 NO 1 Melville NY 11747-4502 United States}, organization = {American Institute of Physics, Ste. 1 NO 1 Melville NY 11747-4502 United States}, author = {Gallup, Kaitlin and Pollock, Tresa} } @article {echlin2012tribeam, title = {The TriBeam System: Femtosecond Laser Based Serial Sectioning}, journal = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 United States.[np]. Jul}, year = {2012}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 United States}, author = {Echlin, Mclean and Mottura, Alessandro and Pollock, Tresa} } @article {rhein2011bimetallic, title = {Bimetallic low thermal-expansion panels of Co-base and silicide-coated Nb-base alloys for high-temperature structural applications}, journal = {Materials Science and Engineering: A}, volume = {528}, number = {12}, year = {2011}, pages = {3973{\textendash}3980}, publisher = {Elsevier}, author = {Rhein, RK and Novak, MD and Levi, CG and Pollock, TM} } @article {adharapurapu2011carburization, title = {Carburization of W-and Re-rich Ni-based alloys in impure helium at 1000{\textdegree} C}, journal = {Corrosion Science}, volume = {53}, number = {1}, year = {2011}, pages = {388{\textendash}398}, publisher = {Elsevier}, author = {Adharapurapu, Raghavendra R and Kumar, Deepak and Zhu, Jun and Pollock, Tresa M} } @article {adharapurapu2011chromia, title = {Chromia-Assisted Decarburization of W-Rich Ni-Based Alloys in Impure Helium at 1273 K (1000{\textdegree} C)}, journal = {Metallurgical and Materials Transactions A}, volume = {42}, number = {5}, year = {2011}, pages = {1229{\textendash}1244}, publisher = {Springer}, author = {Adharapurapu, Raghavendra R and Kumar, Deepak and Zhu, Jun and Torbet, Christopher J and Was, Gary S and Pollock, Tresa M} } @article {mercer2011comparative, title = {A comparative investigation of oxide formation on EQ (Equilibrium) and NiCoCrAlY bond coats under stepped thermal cycling}, journal = {Surface and Coatings Technology}, volume = {205}, number = {8}, year = {2011}, pages = {3066{\textendash}3072}, publisher = {Elsevier}, author = {Mercer, C and Kawagishi, K and Tomimatsu, T and Hovis, D and Pollock, TM} } @article {terbush2011creep, title = {Creep and Elemental Partitioning Behavior of Mg-Al-Ca-Sn Alloys with the Addition of Sr}, journal = {Magnesium Technology 2011}, year = {2011}, pages = {215{\textendash}222}, publisher = {John Wiley \& Sons, Inc.}, author = {TerBush, Jessica R and Chen, Olivia H and Jones, J Wayne and Pollock, Tresa M} } @article {torralva2011critical, title = {The Critical Role of Shock Melting in Ultrafast Laser Machining}, journal = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 United States.[np]. Feb}, year = {2011}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 United States}, author = {Torralva, Ben and Ma, S and Kumar, A and Yalisove, SM and Pollock, TM and Thornton, K} } @article {brundidge2011development, title = {Development of dendritic structure in the liquid-metal-cooled, directional-solidification process}, journal = {Metallurgical and Materials Transactions A}, volume = {42}, number = {9}, year = {2011}, pages = {2723{\textendash}2732}, publisher = {Springer US}, author = {Brundidge, CL and Miller, JD and Pollock, TM} } @article {miller2011heat, title = {Heat Extraction and Structure Evolution in LMC Single-Crystal Growth}, journal = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 United States.[np]. Feb}, year = {2011}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 United States}, author = {Miller, Jonathan and Yuan, Lang and Eisman, Michael and Lee, Peter and Pollock, Tresa} } @article {kumar2011high, title = {High-Temperature Oxidation of Alloy 617 in Helium Containing Part-Per-Million Levels of CO and CO2 as Impurities}, journal = {Metallurgical and Materials Transactions A}, volume = {42}, number = {5}, year = {2011}, pages = {1245{\textendash}1265}, publisher = {Springer}, author = {Kumar, Deepak and Adharapurapu, Raghavendra R and Pollock, Tresa M and Was, Gary S} } @article {perez2011high, title = {High-temperature performance of actively cooled vapor phase strengthened nickel-based thermostructural panels}, journal = {AIAA journal}, volume = {49}, number = {5}, year = {2011}, pages = {1080{\textendash}1086}, author = {P{\'e}rez-Bergquist, Sara and Vermaak, Natasha and Pollock, Tresa M} } @article {kumar2011situ, title = {In situ damage assessment in a cast magnesium alloy during very high cycle fatigue}, journal = {Scripta Materialia}, volume = {64}, number = {1}, year = {2011}, pages = {65{\textendash}68}, publisher = {Elsevier}, author = {Kumar, Anish and Adharapurapu, Raghavendra R and Jones, J Wayne and Pollock, Tresa M} } @article {liu2011situ, title = {In situ synchrotron X-ray imaging of high-cycle fatigue crack propagation in single-crystal nickel-base alloys}, journal = {Acta Materialia}, volume = {59}, number = {13}, year = {2011}, pages = {5103{\textendash}5115}, publisher = {Elsevier}, author = {Liu, L and Husseini, NS and Torbet, CJ and Lee, W-K and Clarke, R and Jones, JW and Pollock, TM} } @article {kumar2011mapping, title = {Mapping of femtosecond laser-induced collateral damage by electron backscatter diffraction}, journal = {Journal of Applied Physics}, volume = {110}, number = {8}, year = {2011}, pages = {083114}, publisher = {AIP Publishing}, author = {Kumar, Anish and Pollock, Tresa M} } @article {berman2011microstructure, title = {Microstructure Evolution in AZ61L During TTMP and Subsequent Annealing Treatments}, journal = {Magnesium Technology 2011}, year = {2011}, pages = {599{\textendash}603}, publisher = {John Wiley \& Sons, Inc.}, author = {Berman, TD and Donlon, W and Decker, R and Huang, J and Pollock, TM and Jones, JW} } @article {echlin2011new, title = {A New Femtosecond Laser-Based Tomography Technique for Multiphase Materials}, journal = {Advanced Materials}, volume = {23}, number = {20}, year = {2011}, pages = {2339{\textendash}2342}, publisher = {Wiley Online Library}, author = {Echlin, McLean P and Husseini, Naji S and Nees, John A and Pollock, Tresa M} } @article {pollock2011oxide, title = {Oxide-Assisted Degradation of Ni-Base Single Crystals During Cyclic Loading: the Role of Coatings}, journal = {Journal of the American Ceramic Society}, volume = {94}, number = {s1}, year = {2011}, publisher = {Blackwell Publishing Inc}, author = {Pollock, Tresa M and Laux, Britta and Brundidge, Clinique L and Suzuki, Akane and He, Ming Y} } @article {tsunekane2011single, title = {Single-crystal solidification of new Co{\textendash}Al{\textendash}W-base alloys}, journal = {Intermetallics}, volume = {19}, number = {5}, year = {2011}, pages = {636{\textendash}643}, publisher = {Elsevier}, author = {Tsunekane, Masafumi and Suzuki, Akane and Pollock, Tresa M} } @article {echlin2011tri, title = {The Tri-Beam System: Femtosecond Laser Based Tomography in a Dual-Beam FIB}, journal = {Microscopy and Microanalysis}, volume = {17}, number = {S2}, year = {2011}, pages = {958{\textendash}959}, publisher = {Cambridge University Press}, author = {Echlin, M and Mottura, A and Pollock, T} } @booklet {pollock20103d, title = {3D simulations for property determination via reconstructed microstructure in nickel-base superalloys.}, year = {2010}, publisher = {Sandia National Laboratories}, author = {Pollock, Tresa M and Thornton, Katsuyo and Rowenhorst, David J and Spowart, Jonathan E and Madison, Jonathan D} } @article {suzuki2010crack, title = {Crack progression during sustained-peak low-cycle fatigue in single-crystal Ni-base superalloy Ren{\'e} N5}, journal = {Metallurgical and Materials Transactions A}, volume = {41}, number = {4}, year = {2010}, pages = {947{\textendash}956}, publisher = {Springer US}, author = {Suzuki, A and Gigliotti, MFX and Hazel, BT and Konitzer, DG and Pollock, TM} } @article {tu2010deformation, title = {Deformation and strain storage mechanisms during high-temperature compression of a powder metallurgy nickel-base superalloy}, journal = {Metallurgical and Materials Transactions A}, volume = {41}, number = {8}, year = {2010}, pages = {2002{\textendash}2009}, publisher = {Springer US}, author = {Tu, Wen J and Pollock, Tresa M} } @conference {terbush2010elemental, title = {Elemental partitioning and microstructure of Mg-Al-Ca-Sn quaternary alloys}, booktitle = {TMS 2010: Aluminium and Magnesium (TMS 14 February 2010 to 18 February 2010)}, year = {2010}, pages = {1{\textendash}5}, publisher = {TMS}, organization = {TMS}, author = {TerBush, Jessica and Chen, Olivia and Jones, J and Pollock, Tresa} } @article {van2010elemental, title = {Elemental partitioning of platinum group metal containing Ni-base superalloys using electron microprobe analysis and atom probe tomography}, journal = {Acta Materialia}, volume = {58}, number = {6}, year = {2010}, pages = {1952{\textendash}1962}, publisher = {Pergamon}, author = {Van Sluytman, JS and La Fontaine, A and Cairney, JM and Pollock, TM} } @article {saddock2010grain, title = {Grain-scale creep processes in Mg{\textendash}Al{\textendash}Ca base alloys: Implications for alloy design}, journal = {Scripta Materialia}, volume = {63}, number = {7}, year = {2010}, pages = {692{\textendash}697}, publisher = {Elsevier}, author = {Saddock, ND and Suzuki, A and Jones, JW and Pollock, TM} } @booklet {adharapurapu2010high, title = {High-Temperature Cyclic Oxidation of Pd/Pt-Modified Nial Bond Coats}, howpublished = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA.[np]. 14-18 Feb}, year = {2010}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA}, author = {Adharapurapu, Raghavendra and Widrevitz, Dan and Zhu, Jun and Lipkin, Don and Dheeradhada, Voroman and Pollock, Tresa} } @article {kumar2010situ, title = {In situ characterization of fatigue damage evolution in a cast Al alloy via nonlinear ultrasonic measurements}, journal = {Acta Materialia}, volume = {58}, number = {6}, year = {2010}, pages = {2143{\textendash}2154}, publisher = {Pergamon}, author = {Kumar, Anish and Torbet, Christopher J and Pollock, Tresa M and Jones, J Wayne} } @booklet {huang2010mechanical, title = {On Mechanical Properties and Microstructures of TTMP Wrought Mg Alloys}, howpublished = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA.[np]. 14-18 Feb}, year = {2010}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA}, author = {Huang, Jack and Arbel, Tamir and Ligeski, Laura and McCaffrey, Jesse and Kulkarni, Sanjay and Jones, J and Pollock, Tresa and Decker, Raymond and LeBeau, Steve} } @article {madison2010modeling, title = {Modeling fluid flow in three-dimensional single crystal dendritic structures}, journal = {Acta Materialia}, volume = {58}, number = {8}, year = {2010}, pages = {2864{\textendash}2875}, publisher = {Elsevier}, author = {Madison, J and Spowart, J and Rowenhorst, D and Aagesen, LK and Thornton, K and Pollock, TM} } @article {pollock2010new, title = {New Co-based g-g' high-temperature alloys}, journal = {JOM}, volume = {62}, number = {1}, year = {2010}, pages = {58{\textendash}63}, publisher = {Springer}, author = {Pollock, TM and Dibbern, J and Tsunekane, M and Zhu, J and Suzuki, A} } @article {terbush2010partitioning, title = {Partitioning of Solute to the Primary $\alpha$-Mg Phase in Creep-Resistant Mg-Al-Ca{\textendash}Based Cast Alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {41}, number = {9}, year = {2010}, pages = {2435{\textendash}2442}, publisher = {Springer}, author = {TerBush, Jessica R and Saddock, Nicholas D and Jones, J Wayne and Pollock, Tresa M} } @booklet {madison2010permeability, title = {Permeability Determination via 3 D Reconstruction of the Mushy Zone of Nickel-Base Single Cyrstals}, howpublished = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA.[np]. 14-18 Feb}, year = {2010}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA}, author = {Madison, Jonathan and Spowart, Jonathan and Rowenhorst, Dave and Thornton, Katsuyo and Pollock, Tresa} } @article {chen2010pulsed, title = {Pulsed-terahertz reflectometry for health monitoring of ceramic thermal barrier coatings}, journal = {Optics express}, volume = {18}, number = {4}, year = {2010}, pages = {3477{\textendash}3486}, publisher = {Optical Society of America}, author = {Chen, Chia-Chu and Lee, Dong-Joon and Pollock, Tresa and Whitaker, John F} } @booklet {brundidge2010real, title = {Real Time Synchrotron Radiography of High Temperature High Cycle Fatigue Crack Growth in Single-Crystal Nickel-Base Superalloys}, howpublished = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA.[np]. 14-18 Feb}, year = {2010}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA}, author = {Brundidge, Clinique L and Husseini, Naji and Hanson, Erik and Torbet, Chris and Clarke, Roy and Jones, JWayne and Pollock, Tresa} } @article {pollock2010weight, title = {Weight loss with magnesium alloys}, journal = {Science}, volume = {328}, number = {5981}, year = {2010}, pages = {986{\textendash}987}, publisher = {American Association for the Advancement of Science}, author = {Pollock, Tresa M} } @article {miao2009crystallographic, title = {Crystallographic fatigue crack initiation in nickel-based superalloy Ren{\'e} 88DT at elevated temperature}, journal = {Acta Materialia}, volume = {57}, number = {20}, year = {2009}, pages = {5964{\textendash}5974}, publisher = {Pergamon}, author = {Miao, Jiashi and Pollock, Tresa M and Jones, J Wayne} } @article {das2009femtosecond, title = {Femtosecond laser machining of cooling holes in thermal barrier coated CMSX4 superalloy}, journal = {Journal of Materials Processing Technology}, volume = {209}, number = {15}, year = {2009}, pages = {5661{\textendash}5668}, publisher = {Elsevier}, author = {Das, Dipak K and Pollock, Tresa M} } @article {das2009formation, title = {Formation of secondary reaction zone in ruthenium bearing nickel based single crystal superalloys with diffusion aluminide coatings}, journal = {Materials Science and Technology}, volume = {25}, number = {2}, year = {2009}, pages = {300{\textendash}308}, publisher = {Taylor \& Francis}, author = {Das, DK and Gleeson, B and Murphy, KS and Ma, S and Pollock, TM} } @article {zhou2009gamma, title = {g' rafting in single crystal blade alloys: a simulation study}, journal = {Materials Science and Technology}, volume = {25}, number = {2}, year = {2009}, pages = {205{\textendash}212}, publisher = {Taylor \& Francis}, author = {Zhou, N and Shen, C and Sarosi, PM and Mills, MJ and Pollock, T and Wang, Y} } @conference {miller2009heat, title = {HEAT EXTRACTION AND DENDRITIC GROWTH IN THE LIQUID-METAL-COOLING (LMC) DIRECTIONAL-SOLIDIFICATION PROCESS}, booktitle = {International Symposium on Liquid Metal Processing and Casting (LMPC 2009)}, year = {2009}, author = {Miller, JD and Pollock, TM} } @article {evans2009mechanism, title = {A mechanism governing oxidation-assisted low-cycle fatigue of superalloys}, journal = {Acta Materialia}, volume = {57}, number = {10}, year = {2009}, pages = {2969{\textendash}2983}, publisher = {Elsevier}, author = {Evans, AG and He, MY and Suzuki, A and Gigliotti, M and Hazel, B and Pollock, TM} } @article {cao2009microstructural, title = {Microstructural evolution and failure characteristics of a NiCoCrAlY bond coat in {\textquotedblleft}hot spot{\textquotedblright} cyclic oxidation}, journal = {Acta Materialia}, volume = {57}, number = {13}, year = {2009}, pages = {3885{\textendash}3894}, publisher = {Elsevier}, author = {Cao, F and Tryon, B and Torbet, CJ and Pollock, TM} } @article {kumar2009nonlinear, title = {Nonlinear ultrasonics for in situ damage detection during high frequency fatigue}, journal = {Journal of Applied Physics}, volume = {106}, number = {2}, year = {2009}, pages = {024904}, publisher = {AIP Publishing}, author = {Kumar, Anish and Torbet, Christopher J and Jones, J Wayne and Pollock, Tresa M} } @article {kozar2009strengthening, title = {Strengthening mechanisms in polycrystalline multimodal nickel-base superalloys}, journal = {Metallurgical and Materials Transactions A}, volume = {40}, number = {7}, year = {2009}, pages = {1588{\textendash}1603}, publisher = {Springer}, author = {Kozar, RW and Suzuki, A and Milligan, WW and Schirra, JJ and Savage, MF and Pollock, TM} } @article {heidloff2009structural, title = {Structural stability of platinum-group-metal-modified $\gamma$+ $\gamma$' Ni-base alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {40}, number = {7}, year = {2009}, pages = {1529{\textendash}1540}, publisher = {Springer US}, author = {Heidloff, AJ and Van Sluytman, J and Pollock, TM and Gleeson, B} } @conference {van2009structure, title = {STRUCTURE REFINEMENT BY A LIQUID METAL COOLING DIRECTIONAL SOLIDIFICATION PROCESS FOR SINGLE CRYSTAL NICKEL-BASE SUPERALLOYS}, booktitle = {International Symposium on Liquid Metal Processing and Casting 2009 (LMPC 2009)}, year = {2009}, author = {Van Drasek, Denar and Wang, Brian and Pollock, Tresa M} } @conference {white2009time, title = {TIME DOMAIN TERAHERTZ NON-DESTRUCTIVE EVALUATION OF AEROTURBINE BLADE THERMAL BARRIER COATINGS}, booktitle = {REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION: Proceedings of the 35th Annual Review of Progress in Quantitative Nondestructive Evaluation}, volume = {1096}, number = {1}, year = {2009}, pages = {434{\textendash}439}, publisher = {AIP Publishing}, organization = {AIP Publishing}, author = {White, Jeffrey and Fichter, G and Chernovsky, A and Whitaker, John F and Das, D and Pollock, Tresa M and Zimdars, David} } @article {mcdonald2008approaching, title = {Approaching non-destructive surface chemical analysis of CMSX-4 superalloy with double-pulsed laser induced breakdown spectroscopy}, journal = {Spectrochimica Acta Part B: Atomic Spectroscopy}, volume = {63}, number = {5}, year = {2008}, pages = {561{\textendash}565}, publisher = {Elsevier}, author = {McDonald, Joel P and Das, Dipak K and Nees, John A and Pollock, Tresa M and Yalisove, Steven M} } @conference {terbush2008comparative, title = {A comparative examination of aging and creep behavior of die-cast MRI230D and AXJ530}, booktitle = {Symposium on Magnesium Technology 2008 (TMS 9 March 2008 to 13 March 2008)}, year = {2008}, pages = {117{\textendash}122}, publisher = {The Minerals, Metals \& Materials Society (TMS)}, organization = {The Minerals, Metals \& Materials Society (TMS)}, author = {TerBush, Jessica and Jones, J and Pollock, Tresa} } @article {cao2008creep, title = {Creep deformation mechanisms in Ru-Ni-Al ternary B2 alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {39}, number = {1}, year = {2008}, pages = {39{\textendash}49}, publisher = {Springer}, author = {Cao, F and Pollock, TM} } @article {das2008depth, title = {Depth-profiling study of a thermal barrier coated superalloy using femtosecond laser-induced breakdown spectroscopy}, journal = {Spectrochimica Acta Part B: Atomic Spectroscopy}, volume = {63}, number = {1}, year = {2008}, pages = {27{\textendash}36}, publisher = {Elsevier}, author = {Das, DK and McDonald, JP and Yalisove, SM and Pollock, TM} } @article {das2008detection, title = {Detection of a marker layer in a 7YSZ thermal barrier coating by femtosecond laser-induced breakdown spectroscopy}, journal = {Surface and Coatings Technology}, volume = {202}, number = {16}, year = {2008}, pages = {3940{\textendash}3946}, publisher = {Elsevier}, author = {Das, Dipak K and McDonald, Joel P and Levi, Carlos G and Yalisove, Steve M and Pollock, Tresa M} } @article {terbush2008dislocation, title = {Dislocation substructures of three die-cast Mg{\textendash}Al{\textendash}Ca-based alloys}, journal = {Scripta Materialia}, volume = {58}, number = {10}, year = {2008}, pages = {914{\textendash}917}, publisher = {Pergamon}, author = {TerBush, JR and Suzuki, Akane and Saddock, ND and Jones, JW and Pollock, TM} } @article {mcdonald2008femtosecond, title = {Femtosecond pulsed laser ablation dynamics and ablation morphology of nickel based superalloy CMSX-4}, journal = {Journal of Applied Physics}, volume = {103}, number = {9}, year = {2008}, pages = {093111}, publisher = {AIP Publishing}, author = {McDonald, Joel P and Ma, Shuwei and Pollock, Tresa M and Yalisove, Steven M and Nees, John A} } @article {das2008femtosecond, title = {Femtosecond pulsed laser damage characteristics of 7\% Y2O3-ZrO2 thermal barrier coating}, journal = {Applied Physics A}, volume = {91}, number = {3}, year = {2008}, pages = {421{\textendash}428}, publisher = {Springer}, author = {Das, DK and McDonald, JP and Yalisove, SM and Pollock, TM} } @article {das2008formation, title = {Formation of secondary reaction zones in diffusion aluminide-coated Ni-base single-crystal superalloys containing ruthenium}, journal = {Metallurgical and Materials Transactions A}, volume = {39}, number = {7}, year = {2008}, pages = {1647{\textendash}1657}, publisher = {Springer}, author = {Das, Dipak K and Murphy, Kenneth S and Ma, Shuwei and Pollock, Tresa M} } @article {suzuki2008high, title = {High-temperature strength and deformation of $\gamma$/$\gamma$' two-phase Co{\textendash}Al{\textendash}W-base alloys}, journal = {Acta Materialia}, volume = {56}, number = {6}, year = {2008}, pages = {1288{\textendash}1297}, publisher = {Elsevier}, author = {Suzuki, Akane and Pollock, Tresa M} } @article {kumah2008situ, title = {In Situ Imaging of High Cycle Fatigue Crack Growth in Single Crystal Nickel-Base Superalloys by Synchrotron X-Radiation}, journal = {Ann Arbor}, volume = {1001}, year = {2008}, pages = {48109}, author = {Kumah, Divine P and Clarke, Roy and Pollock, Tresa M and Jones, J Wayne} } @article {liu2008situ, title = {In situ imaging of high cycle fatigue crack growth in single crystal nickel-base superalloys by synchrotron X-radiation}, journal = {Journal of Engineering Materials and Technology}, volume = {130}, number = {2}, year = {2008}, pages = {021008}, publisher = {American Society of Mechanical Engineers}, author = {Liu, Liu and Husseini, Naji S and Torbet, Christopher J and Kumah, Divine P and Clarke, Roy and Pollock, Tresa M and Jones, J Wayne} } @article {carroll2008interfacial, title = {Interfacial Dislocation Networks and creep in directional coarsened Ru-containing nickel-base single-crystal superalloys}, journal = {Metallurgical and Materials Transactions A}, volume = {39}, number = {6}, year = {2008}, pages = {1290{\textendash}1307}, publisher = {Springer US}, author = {Carroll, LJ and Feng, Q and Pollock, TM} } @conference {pollock2008intermetallic, title = {Intermetallic Bond Coats: Systems Compatibility and Platinum-Group Metal Additions}, booktitle = {MRS Proceedings}, volume = {1128}, year = {2008}, pages = {1128{\textendash}U06}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, author = {Pollock, Tresa and Widrevitz, Dan and Pong, Russell and Cao, Fang and Tryon, Bryan} } @article {husseini2008mapping, title = {Mapping single-crystal dendritic microstructure and defects in nickel-base superalloys with synchrotron radiation}, journal = {Acta Materialia}, volume = {56}, number = {17}, year = {2008}, pages = {4715{\textendash}4723}, publisher = {Pergamon}, author = {Husseini, Naji S and Kumah, Divine P and Jian, Z Yi and Torbet, Christopher J and Arms, Dohn A and Dufresne, Eric M and Pollock, Tresa M and Jones, J Wayne and Clarke, Roy} } @article {johnson2008post, title = {Post-fabrication vapor phase strengthening of nickel-based sheet alloys for thermostructural panels}, journal = {Acta Materialia}, volume = {56}, number = {17}, year = {2008}, pages = {4577{\textendash}4584}, publisher = {Elsevier}, author = {Johnson, SJ and Tryon, B and Pollock, TM} } @article {suzuki2008precipitation, title = {Precipitation strengthening of a Mg-Al-Ca{\textendash}based AXJ530 die-cast alloy}, journal = {Metallurgical and Materials Transactions A}, volume = {39}, number = {3}, year = {2008}, pages = {696{\textendash}702}, publisher = {Springer US}, author = {Suzuki, Akane and Saddock, ND and TerBush, JR and Powell, BR and Jones, JW and Pollock, TM} } @conference {chen2008terahertz, title = {Terahertz characterization of interfacial oxide layers and voids for health monitoring of ceramic coatings}, booktitle = {2009 34th International Conference on Infrared, Millimeter, and Terahertz Waves}, year = {2008}, author = {Chen, Chia-Chu and Lee, Dong-Joon and Pollock, Tresa and Whitaker, John F} } @article {madison2008three, title = {The three-dimensional reconstruction of the dendritic structure at the solid-liquid interface of a Ni-based single crystal}, journal = {JOM}, volume = {60}, number = {7}, year = {2008}, pages = {26{\textendash}30}, publisher = {Springer}, author = {Madison, J and Spowart, JE and Rowenhorst, DJ and Pollock, TM} } @conference {white2008time, title = {Time-domain terahertz mapping of thickness and degradation of aircraft turbine blade thermal barrier coatings}, booktitle = {Conference on Lasers and Electro-Optics}, year = {2008}, pages = {CThN7}, publisher = {Optical Society of America}, organization = {Optical Society of America}, author = {White, Jeffrey and Fichter, G and Chernovsky, A and Zimdars, David A and Whitaker, John F and Das, D and Pollock, Tresa M} } @article {godlewski20072006, title = {2006-01-0319 A Test Method for Quantifying Residual Stress Due to Heat Treatment in Metals}, journal = {SAE TRANSACTIONS}, volume = {115}, number = {5}, year = {2007}, pages = {273}, publisher = {AMERICAN TECHNICAL PUBLISHERS LTD}, author = {Godlewski, LA and Su, X and Allison, JE and Gustafson, P and Pollock, TM} } @conference {cao2007compression, title = {COMPRESSION CREEP BEHAVIOR OF B 2 AL-NI-RU TERNARY ALLOYS}, booktitle = {Advanced Intermetallic-Based Alloys(MRS Symposium Proceedings Series Volume 980)}, volume = {980}, year = {2007}, pages = {45{\textendash}50}, author = {Cao, Fang and Pollock, Tresa M} } @article {feng2007cyclic, title = {Cyclic oxidation of Ru-containing single crystal superalloys at 1100 C}, journal = {Materials Science and Engineering: A}, volume = {458}, number = {1}, year = {2007}, pages = {184{\textendash}194}, publisher = {Elsevier}, author = {Feng, Q and Tryon, B and Carroll, LJ and Pollock, TM} } @article {cao2007deformation, title = {Deformation mechanisms in a Ru{\textendash}Ni{\textendash}Al ternary B2 intermetallic alloy}, journal = {Acta materialia}, volume = {55}, number = {8}, year = {2007}, pages = {2715{\textendash}2727}, publisher = {Elsevier}, author = {Cao, F and Pollock, TM} } @article {ma2007development, title = {Development of $\gamma$ phase stacking faults during high temperature creep of Ru-containing single crystal superalloys}, journal = {Acta Materialia}, volume = {55}, number = {17}, year = {2007}, pages = {5802{\textendash}5812}, publisher = {Pergamon}, author = {Ma, S and Carroll, L and Pollock, TM} } @conference {mcdonald2007dynamics, title = {Dynamics of Ultrafast Laser Induced Damage in Single Crystal Ni-Based Superalloy During Machining}, booktitle = {Advanced Intermetallic-Based Alloys(MRS Symposium Proceedings Series Volume 980)}, volume = {980}, year = {2007}, pages = {571{\textendash}576}, author = {McDonald, Joel P and Ma, Shuwei and Nees, John A and Pollock, Tresa M and Yalisove, Steven M} } @article {suzuki2007effect, title = {Effect of Sr additions on the microstructure and strength of a Mg-Al-Ca ternary alloy}, journal = {Metallurgical and Materials Transactions A}, volume = {38}, number = {2}, year = {2007}, pages = {420{\textendash}427}, publisher = {Springer US}, author = {Suzuki, Akane and Saddock, ND and Riester, L and Lara-Curzio, E and Jones, JW and Pollock, TM} } @article {carroll2007elemental, title = {Elemental partitioning in Ru-containing nickel-base single crystal superalloys}, journal = {Materials Science and Engineering: A}, volume = {457}, number = {1}, year = {2007}, pages = {292{\textendash}299}, publisher = {Elsevier}, author = {Carroll, LJ and Feng, Q and Mansfield, JF and Pollock, TM} } @article {ma2007femtosecond, title = {Femtosecond laser ablation regimes in a single-crystal superalloy}, journal = {Metallurgical and Materials Transactions A}, volume = {38}, number = {13}, year = {2007}, pages = {2349{\textendash}2357}, publisher = {Springer}, author = {Ma, S and McDonald, JP and Tryon, B and Yalisove, SM and Pollock, TM} } @article {suzuki2007flow, title = {Flow stress anomalies in $\gamma$/$\gamma$' two-phase Co{\textendash}Al{\textendash}W-base alloys}, journal = {Scripta Materialia}, volume = {56}, number = {5}, year = {2007}, pages = {385{\textendash}388}, publisher = {Elsevier}, author = {Suzuki, Akane and DeNolf, Garret C and Pollock, Tresa M} } @conference {suzuki2007high, title = {High Temperature Strength of Co-based gamma/gamma{\textquoteright} Superalloys}, booktitle = {Advanced Intermetallic-Based Alloys(MRS Symposium Proceedings Series Volume 980)}, volume = {980}, year = {2007}, pages = {499{\textendash}504}, author = {Suzuki, Akane and DeNolf, Garret C and Pollock, Tresa M} } @article {tryon2007hybrid, title = {Hybrid intermetallic Ru/Pt-modified bond coatings for thermal barrier systems}, journal = {Surface and Coatings Technology}, volume = {202}, number = {2}, year = {2007}, pages = {349{\textendash}361}, publisher = {Elsevier}, author = {Tryon, B and Murphy, KS and Yang, JY and Levi, CG and Pollock, TM} } @conference {wang2007influence, title = {Influence of Ru and Cr on the heat-treated microstructure of Ni-based superalloys}, booktitle = {Materials science forum}, volume = {546}, year = {2007}, pages = {1207{\textendash}1210}, publisher = {Trans Tech Publications}, organization = {Trans Tech Publications}, author = {Wang, WB and Feng, Qiang and Carroll, LJ and Wang, YL and Chen, Guo Liang and Pollock, TM} } @article {cao2007oxidation, title = {Oxidation of ruthenium aluminide-based alloys: The role of microstructure and platinum additions}, journal = {Intermetallics}, volume = {15}, number = {1}, year = {2007}, pages = {34{\textendash}43}, publisher = {Elsevier}, author = {Cao, F and Nandy, TK and Stobbe, D and Pollock, TM} } @booklet {saddock2007permanent, title = {Permanent Mold Casting and Creep Behavior of Mg-4 Al-4 X:(Ca, Ce, La, Sr) Alloys}, year = {2007}, publisher = {SAE Technical Paper}, author = {Saddock, Nicholas D and Suzuki, Akane and TerBush, Jessica R and Jones, J Wayne and Pollock, Tresa M and Zindel, Jake and Allison, John E} } @article {shyam2007small, title = {Small fatigue crack growth in metallic materials: a model and its application to engineering alloys}, journal = {Acta Materialia}, volume = {55}, number = {19}, year = {2007}, pages = {6606{\textendash}6616}, publisher = {Elsevier}, author = {Shyam, Amit and Allison, John E and Szczepanski, Christopher J and Pollock, Tresa M and Jones, J Wayne} } @article {kulkarni2007ternary, title = {Ternary diffusion in a RuAl-NiAl couple}, journal = {Journal of Phase Equilibria and Diffusion}, volume = {28}, number = {6}, year = {2007}, pages = {503{\textendash}509}, publisher = {Springer US}, author = {Kulkarni, KN and Tryon, B and Pollock, TM and Dayananda, MA} } @article {elliott2007thermal, title = {Thermal analysis of the Bridgman and liquid-metal-cooled directional solidification investment casting processes}, journal = {Metallurgical and Materials Transactions A}, volume = {38}, number = {4}, year = {2007}, pages = {871{\textendash}882}, publisher = {Springer US}, author = {Elliott, AJ and Pollock, TM} } @article {yi2007ultrasonic, title = {Ultrasonic fatigue of a single crystal Ni-base superalloy at 1000 C}, journal = {Materials Science and Engineering: A}, volume = {443}, number = {1}, year = {2007}, pages = {142{\textendash}149}, publisher = {Elsevier}, author = {Yi, JZ and Torbet, CJ and Feng, Q and Pollock, TM and Jones, JW} } @conference {cao2006compression, title = {Compression Creep Behavior of B2 AL-Ni-Ru Ternary Alloys}, booktitle = {MRS Proceedings}, volume = {980}, year = {2006}, pages = {0980{\textendash}II01}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, author = {Cao, Fang and Pollock, Tresa M} } @conference {mcdonald2006dynamics, title = {Dynamics of Ultrafast Laser Induced Damage in Single Crystal Ni-Based Superalloy During Machining}, booktitle = {MRS Proceedings}, volume = {980}, year = {2006}, pages = {0980{\textendash}II05}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, author = {McDonald, Joel P and Ma, Shuwei and Nees, John A and Pollock, Tresa M and Yalisove, Steven M} } @article {tryon2006experimental, title = {Experimental assessment of the Ru{\textendash}Al{\textendash}Ni ternary phase diagram at 1000 and 1100{\textdegree} C}, journal = {Materials Science and Engineering: A}, volume = {430}, number = {1}, year = {2006}, pages = {266{\textendash}276}, publisher = {Elsevier}, author = {Tryon, B and Pollock, TM} } @article {cao2006experimental, title = {Experimental investigation and thermodynamic modelling of the Mg{\textendash}Al-rich region of the Mg{\textendash}Al{\textendash}Sr System}, journal = {Zeitschrift f{\"u}r Metallkunde}, volume = {97}, number = {4}, year = {2006}, pages = {422{\textendash}428}, publisher = {Carl Hanser Verlag}, author = {Cao, Hongbo and Zhu, Jun and Zhang, Chuan and Wu, Kaisheng and Saddock, Nicholas D and Jones, J Wayne and Pollock, Tresa M and Schmid-Fetzer, Rainer and Chang, Y Austin} } @article {feng2006femtosecond, title = {Femtosecond laser machining of single-crystal superalloys through thermal barrier coatings}, journal = {Materials Science and Engineering: A}, volume = {430}, number = {1}, year = {2006}, pages = {203{\textendash}207}, publisher = {Elsevier}, author = {Feng, Q and Picard, YN and McDonald, JP and Van Rompay, PA and Yalisove, SM and Pollock, TM} } @article {wu2006grain, title = {Grain-scale strain mapping for analysis of slip activity in polycrystalline B2 RuAl}, journal = {Philosophical Magazine}, volume = {86}, number = {25-26}, year = {2006}, pages = {3995{\textendash}4008}, publisher = {Taylor \& Francis}, author = {Wu, A and De Graef, M and Pollock, TM} } @article {carroll2006high, title = {High refractory, low misfit Ru-containing single-crystal superalloys}, journal = {Metallurgical and Materials Transactions A}, volume = {37}, number = {10}, year = {2006}, pages = {2927{\textendash}2938}, publisher = {Springer}, author = {Carroll, LJ and Feng, Q and Mansfield, JF and Pollock, TM} } @conference {suzuki2006high, title = {High Temperature Strength of Co-based $\gamma$/$\gamma${\textquoteright}Superalloys}, booktitle = {MRS Proceedings}, volume = {980}, year = {2006}, pages = {0980{\textendash}II08}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, author = {Suzuki, Akane and DeNolf, Garret C and Pollock, Tresa M} } @booklet {srolovitz2006knowledge, title = {Knowledge Oriented Materials Engineering of Layered Thermal Barrier Systems (NOMELT)}, year = {2006}, publisher = {DTIC Document}, author = {Srolovitz, David and Hemker, Kevin and Evans, Anthony and Hutchinson, John and Pollock, Tresa and Smith, John} } @article {mendis2006microstructural, title = {Microstructural observations of as-prepared and thermal cycled NiCoCrAlY bond coats}, journal = {Surface and Coatings Technology}, volume = {201}, number = {7}, year = {2006}, pages = {3918{\textendash}3925}, publisher = {Elsevier}, author = {Mendis, BG and Tryon, B and Pollock, TM and Hemker, KJ} } @conference {saddock2006microstructure, title = {Microstructure and mechanical properties of permanent mold cast Mg-4 A1-4 (Ca, Ce, La, or Sr) ternary alloys}, booktitle = {Symposium on Magnesium Technology 2006 (TMS 12 March 2006 to 16 March 2006)}, year = {2006}, pages = {77{\textendash}82}, publisher = {The Minerals, Metals \& Materials Society (TMS)}, organization = {The Minerals, Metals \& Materials Society (TMS)}, author = {Saddock, Nicholas and Suzuki, Akane and TerBush, Jessica and Heininger, Eric and Zindel, Jacob and Allison, John and Pollock, Tresa and Jones, J} } @article {nandy2006microstructure, title = {Microstructure and properties of blended Mg- Al alloys fabricated by semisolid processing}, journal = {Metallurgical and Materials Transactions A}, volume = {37}, number = {12}, year = {2006}, pages = {3725{\textendash}3736}, publisher = {Springer}, author = {Nandy, TK and Messing, Rebecca M and Jones, J Wayne and Pollock, Tresa M and Walukas, DM and Decker, RF} } @article {tryon2006multilayered, title = {Multilayered ruthenium-modified bond coats for thermal barrier coatings}, journal = {Metallurgical and Materials Transactions A}, volume = {37}, number = {11}, year = {2006}, pages = {3347{\textendash}3358}, publisher = {Springer}, author = {Tryon, B and Feng, Q and Pollock, TM and Wellman, RG and Nicholls, JR and Murphy, KS and Yang, J and Levi, CG} } @article {pollock2006nickel, title = {Nickel-based superalloys for advanced turbine engines: chemistry, microstructure and properties}, journal = {Journal of propulsion and power}, volume = {22}, number = {2}, year = {2006}, pages = {361{\textendash}374}, author = {Pollock, Tresa M and Tin, Sammy} } @article {suzuki2006phase, title = {Phase equilibria in the Mg-Al-Ca ternary system at 773 and 673 K}, journal = {Metallurgical and Materials Transactions A}, volume = {37}, number = {3}, year = {2006}, pages = {975{\textendash}983}, publisher = {Springer}, author = {Suzuki, Akane and Saddock, Nicholas D and Jones, J Wayne and Pollock, Tresa M} } @article {das2006qualitative, title = {Qualitative Characterization of a Thermal Barrier Coating System Using Femtosecond Laser-Induced Breakdown Spectroscopy}, journal = {MATERIALS SCIENCE AND TECHNOLOGY-ASSOCIATION FOR IRON AND STEEL TECHNOLOGY-}, volume = {5}, year = {2006}, pages = {621}, publisher = {ASSOCIATION FO IRON AND STEEL INDUSTRY}, author = {Das, DK and McDonald, JP and Yalisove, SM and Pollock, TM} } @article {tryon2006ruthenium, title = {Ruthenium-containing bond coats for thermal barrier coating systems}, journal = {JoM}, volume = {58}, number = {1}, year = {2006}, pages = {53{\textendash}59}, publisher = {Springer}, author = {Tryon, B and Cao, F and Murphy, KS and Levi, CG and Pollock, TM} } @article {feng2006soldification, title = {Soldification segregation in ruthenium-containing nickel-base superalloys}, journal = {Metallurgical and Materials Transactions A}, volume = {37}, number = {6}, year = {2006}, pages = {1949{\textendash}1962}, publisher = {Springer-Verlag}, author = {Feng, Q and Carroll, LJ and Pollock, TM} } @booklet {godlewski2006test, title = {A test method for quantifying residual stress due to heat treatment in metals}, year = {2006}, publisher = {SAE Technical Paper}, author = {Godlewski, Larry A and Su, Xuming and Allison, John E and Gustafson, Peter and Pollock, Tresa M} } @article {feng2005femtosecond, title = {Femtosecond laser micromachining of a single-crystal superalloy}, journal = {Scripta materialia}, volume = {53}, number = {5}, year = {2005}, pages = {511{\textendash}516}, publisher = {Elsevier}, author = {Feng, Q and Picard, YN and Liu, H and Yalisove, SM and Mourou, G and Pollock, TM} } @conference {feng2005new, title = {New phases in a multicomponent high ruthenium single crystal superalloy}, booktitle = {Materials Science Forum}, volume = {475}, year = {2005}, pages = {655{\textendash}660}, publisher = {Trans Tech Publications}, organization = {Trans Tech Publications}, author = {Feng, Q and Rowland, LJ and Pollock, TM} } @article {suzuki2005phase, title = {Phase Transformation and Creep of Mg-Al-Ca Based Die-Cast Alloys}, journal = {Essential Readings in Magnesium Technology}, year = {2005}, pages = {291{\textendash}296}, publisher = {John Wiley \& Sons, Inc.}, author = {Suzuki, Akane and Saddock, Nicholas D and Jones, J Wayne and Pollock, Tresa M} } @article {saddock2005solidification, title = {Solidification and Microstructure of Mg-Al-(Ca, Sr, Ce, La) Ternary Alloys}, journal = {Essential Readings in Magnesium Technology}, year = {2005}, pages = {199{\textendash}204}, publisher = {John Wiley \& Sons, Inc.}, author = {Saddock, ND and Suzuki, A and Wu, K and Wildy, SC and Chang, YA and Pollock, TM and Jones, JW} } @article {suzuki2005solidification, title = {Solidification paths and eutectic intermetallic phases in Mg{\textendash}Al{\textendash}Ca ternary alloys}, journal = {Acta Materialia}, volume = {53}, number = {9}, year = {2005}, pages = {2823{\textendash}2834}, publisher = {Elsevier}, author = {Suzuki, A and Saddock, ND and Jones, JW and Pollock, TM} } @article {feng2004deformation, title = {Deformation of Ru{\textendash}Al{\textendash}Ta ternary alloys}, journal = {Intermetallics}, volume = {12}, number = {7}, year = {2004}, pages = {755{\textendash}762}, publisher = {Elsevier}, author = {Feng, Q and Nandy, TK and Tryon, B and Pollock, TM} } @conference {shyam2004development, title = {Development of ultrasonic fatigue for rapid, high temperature fatigue studies in turbine engine materials}, booktitle = {10th International Symposium on Superalloys, Champion, PA, September}, year = {2004}, pages = {19{\textendash}23}, author = {Shyam, A and Torbet, CJ and Jha, SK and Larsen, JM and Caton, MJ and Szczepanski, CJ and Pollock, TM and Jones, JW} } @article {elliott2004directional, title = {Directional solidification of large superalloy castings with radiation and liquid-metal cooling: a comparative assessment}, journal = {Metallurgical and Materials Transactions A}, volume = {35}, number = {10}, year = {2004}, pages = {3221{\textendash}3231}, publisher = {Springer-Verlag}, author = {Elliott, AJ and Pollock, TM and Tin, S and King, WT and Huang, S-C and Gigliotti, MFX} } @article {cerreta2004dynamic, title = {Dynamic deformation and damage in cast $\gamma$-TiAl during taylor cylinder impact: Experiments and model validation}, journal = {Metallurgical and Materials Transactions A}, volume = {35}, number = {9}, year = {2004}, pages = {2557{\textendash}2566}, publisher = {Springer}, author = {Cerreta, E and Chen, SR and Gray III, GT and Pollock, TM} } @article {tryon2004intermetallic, title = {Intermetallic phases formed by ruthenium{\textendash}nickel alloy interdiffusion}, journal = {Intermetallics}, volume = {12}, number = {7}, year = {2004}, pages = {957{\textendash}962}, publisher = {Elsevier}, author = {Tryon, B and Feng, Q and Pollock, T} } @conference {feng2004new, title = {New Phases in Ruthenium-Containing Single-Crystal Superalloys}, booktitle = {Superalloys 2004: The Tenth International Symposium on Superalloys}, year = {2004}, pages = {769{\textendash}778}, author = {Feng, Q and Nandy, TK and Rowland, LJ and Tryon, B and Banerjee, D and Pollock, TM} } @article {feng2004observation, title = {Observation of a Ru-rich Heusler phase in a multicomponent Ni-base superalloy}, journal = {Scripta materialia}, volume = {50}, number = {6}, year = {2004}, pages = {849{\textendash}854}, publisher = {Elsevier}, author = {Feng, Q and Nandy, TK and Pollock, TM} } @article {tin2004predicting, title = {Predicting freckle formation in single crystal Ni-base superalloys}, journal = {Journal of materials science}, volume = {39}, number = {24}, year = {2004}, pages = {7199{\textendash}7205}, publisher = {Springer}, author = {Tin, S and Pollock, TM} } @article {feng2004re, title = {The Re (Ru)-rich $δ$-phase in Ru-containing superalloys}, journal = {Materials Science and Engineering: A}, volume = {373}, number = {1}, year = {2004}, pages = {239{\textendash}249}, publisher = {Elsevier}, author = {Feng, Q and Nandy, TK and Pollock, TM} } @article {suzuki2004structure, title = {Structure and transition of eutectic (Mg, Al) 2 Ca Laves phase in a die-cast Mg{\textendash}Al{\textendash}Ca base alloy}, journal = {Scripta Materialia}, volume = {51}, number = {10}, year = {2004}, pages = {1005{\textendash}1010}, publisher = {Pergamon}, author = {Suzuki, A and Saddock, ND and Jones, JW and Pollock, TM} } @article {cerreta2004symposium, title = {Symposium on Dynamic Deformation: Constitutive Modeling, Grain Size, and Other Effects{\textendash}In Honor of Prof. Ronald W. Armstrong-Dynamic Deformation and Damage in Cast g-TiAl during Taylor Cylinder}, journal = {Metallurgical and Materials Transactions-Series A}, volume = {35}, number = {9}, year = {2004}, pages = {2557{\textendash}2566}, publisher = {Warrendale, PA: Minerals, Metals \& Materials Society; Materials Park, OH: ASM International, c1994-}, author = {Cerreta, E and Gray, GT and Chen, SR and Pollock, TM} } @article {tryon2004thermal, title = {Thermal expansion behavior of ruthenium aluminides}, journal = {Scripta Materialia}, volume = {50}, number = {6}, year = {2004}, pages = {845{\textendash}848}, publisher = {Pergamon}, author = {Tryon, B and Pollock, TM and Gigliotti, MFX and Hemker, K} } @article {lu2004transmission, title = {Transmission electron microscopy study of complex planar faults in Ru{\textendash}Al{\textendash}0.5 at.\% B}, journal = {Philosophical Magazine}, volume = {84}, number = {22}, year = {2004}, pages = {2317{\textendash}2329}, publisher = {Taylor \& Francis}, author = {Lu, D-C and De Graef, M and Pollock{\textdagger}, TM} } @conference {elliott2003defect, title = {Defect reduction in large superalloy castings by liquid-tin assisted solidification.}, booktitle = {PARSONS 2003: Sixth International Charles Parsons Turbine Conference}, year = {2003}, pages = {649{\textendash}661}, author = {Elliott, AJ and Pollock, TM and Tin, S and King, WT and Huang, S-C and Gigliotti, MFX} } @article {nandy2003deformation, title = {Deformation of a platinum-containing RuAl intermetallic by< 111> dislocations}, journal = {Scripta materialia}, volume = {48}, number = {8}, year = {2003}, pages = {1087{\textendash}1092}, publisher = {Elsevier}, author = {Nandy, TK and Feng, Q and Pollock, TM} } @article {nandy2003elevated, title = {Elevated temperature deformation and dynamic strain aging in polycrystalline RuAl alloys}, journal = {Intermetallics}, volume = {11}, number = {10}, year = {2003}, pages = {1029{\textendash}1038}, publisher = {Elsevier}, author = {Nandy, TK and Feng, Q and Pollock, TM} } @conference {nandy2003mechanical, title = {Mechanical Behavior of Ternary and Quaternary RuAl Alloys}, booktitle = {MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS}, volume = {753}, year = {2003}, pages = {89{\textendash}96}, publisher = {Cambridge Univ Press}, organization = {Cambridge Univ Press}, author = {Nandy, TK and Feng, Q and Banerjee, D and Gigliotti, MFX and Pollock, TM} } @article {biery2003method, title = {A method for measuring microstructural-scale strains using a scanning electron microscope: applications to $\gamma$-titanium aluminides}, journal = {Metallurgical and Materials Transactions A}, volume = {34}, number = {10}, year = {2003}, pages = {2301{\textendash}2313}, publisher = {Springer-Verlag}, author = {Biery, Nicholas and De Graef, Marc and Pollock, Tresa M} } @article {moreno2003microstructural, title = {Microstructural stability and creep of rare-earth containing magnesium alloys}, journal = {Scripta Materialia}, volume = {48}, number = {8}, year = {2003}, pages = {1029{\textendash}1034}, publisher = {Elsevier}, author = {Moreno, IP and Nandy, TK and Jones, JW and Allison, JE and Pollock, TM} } @article {tin2003phase, title = {Phase instabilities and carbon additions in single-crystal nickel-base superalloys}, journal = {Materials Science and Engineering: A}, volume = {348}, number = {1}, year = {2003}, pages = {111{\textendash}121}, publisher = {Elsevier}, author = {Tin, S and Pollock, TM} } @article {feng2003solidification, title = {Solidification of high-refractory ruthenium-containing superalloys}, journal = {Acta Materialia}, volume = {51}, number = {1}, year = {2003}, pages = {269{\textendash}284}, publisher = {Elsevier}, author = {Feng, Q and Nandy, TK and Tin, S and Pollock, TM} } @article {tin2003stabilization, title = {Stabilization of thermosolutal convective instabilities in Ni-based single-crystal superalloys: Carbide precipitation and Rayleigh numbers}, journal = {Metallurgical and Materials Transactions A}, volume = {34}, number = {9}, year = {2003}, pages = {1953{\textendash}1967}, publisher = {Springer-Verlag}, author = {Tin, S and Pollock, TM} } @article {pollock2002dislocations, title = {Dislocations and high-temperature plastic deformation of superalloy single crystals}, journal = {Dislocations in solids}, volume = {11}, year = {2002}, pages = {547{\textendash}618}, publisher = {Elsevier}, author = {Pollock, TM and Field, RD} } @conference {nandy2002mechanical, title = {Mechanical Behavior of Ternary and Quaternary Rual Alloys}, booktitle = {MRS Proceedings}, volume = {753}, year = {2002}, pages = {BB2{\textendash}11}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, author = {Nandy, TK and Feng, Q and Banerjee, D and Gigliotti, MFX and Pollock, TM} } @article {gray2002strain, title = {Strain hardening}, journal = {Intermetallic Compounds-Principles and Practice: Progress, Volume 3}, year = {2002}, pages = {361{\textendash}377}, publisher = {John Wiley \& Sons, Ltd}, author = {Gray, George T and Pollock, Tresa M} } @article {biery2002use, title = {Use of Weibull statistics to quantify property variability in TiAl alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {33}, number = {10}, year = {2002}, pages = {3127{\textendash}3136}, publisher = {Springer}, author = {Biery, Nicholas and De Graef, Marc and Beuth, Jack and Raban, Rafel and Elliott, Andrew and Pollock, Tresa M and AUSTIN, CURT} } @article {gilchrist2001cast, title = {Cast gamma titanium aluminides for low pressure turbine blades: a design case study for intermetallics}, journal = {Minerals, Metals and Materials Society/AIME, Structural Intermetallics 2001(USA),}, year = {2001}, pages = {3{\textendash}12}, author = {Gilchrist, Alan and Pollock, Tresa M} } @article {pollock2001comparative, title = {A comparative analysis of low temperature deformation in B2 aluminides}, journal = {Materials Science and Engineering: A}, volume = {317}, number = {1}, year = {2001}, pages = {241{\textendash}248}, publisher = {Elsevier}, author = {Pollock, TM and Lu, DC and Shi, X and Eow, K} } @conference {steif2001dynamic, title = {DYNAMIC DEFORMATION AND DAMAGE IN CAST Y-TIAL DURING TAYLOR CYLINDER IMPACT: EXPERIMENTS AND MODEL VALIDATION}, booktitle = {Structural Intermetallics, 2001: ISSI: Proceedings of the Third International Symposium on Structural Intermetallics}, volume = {1}, year = {2001}, pages = {269}, publisher = {Tms}, organization = {Tms}, author = {Steif, PS and Pollock, TM} } @article {li2001effect, title = {On the effect of low and high pressure hydrogen charging on the oxidation of a Ti{\textendash}48Al{\textendash}2Cr{\textendash}2Nb alloy}, journal = {Materials Science and Engineering: A}, volume = {318}, number = {1}, year = {2001}, pages = {224{\textendash}234}, publisher = {Elsevier}, author = {Li, K and Pollock, TM and De Graef, M and Habel, U and Thompson, AW} } @article {biery2001influence, title = {Influence of microstructure and strain distribution on failure properties in intermetallic TiAl-based alloys}, journal = {Materials Science and Engineering: A}, volume = {319}, year = {2001}, pages = {613{\textendash}617}, publisher = {Elsevier}, author = {Biery, NE and De Graef, M and Pollock, TM} } @article {moreno2001microstructural, title = {Microstructural characterization of a die-cast magnesium-rare earth alloy}, journal = {Scripta Materialia}, volume = {45}, number = {12}, year = {2001}, pages = {1423{\textendash}1429}, publisher = {Elsevier}, author = {Moreno, IP and Nandy, TK and Jones, JW and Allison, JE and Pollock, TM} } @article {smith2001role, title = {The role of impact damage and fatigue strength reduction in gamma titanium aluminide alloys}, journal = {Structural Intermetallics}, year = {2001}, pages = {259{\textendash}268}, author = {Smith, R and Harding, T and Jones, JW and Steif, P and Pollock, TM} } @booklet {boyce2001special, title = {Special issue-Micromechanics and micromechanisms of deformation and fracture: A special issue in honor of professor Ali S. Argon-Preface}, year = {2001}, publisher = {ELSEVIER SCIENCE SA PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, author = {Boyce, MC and Pollock, TM and Hsia, KJ} } @article {tin2001stabilization, title = {Stabilization of thermosolutal convective instabilities in Ni-based single-crystal superalloys: Carbon additions and freckle formation}, journal = {Metallurgical and Materials Transactions A}, volume = {32}, number = {7}, year = {2001}, pages = {1743{\textendash}1753}, publisher = {Springer-Verlag}, author = {Tin, S and Pollock, TM and Murphy, W} } @conference {tin2000carbides, title = {Carbides and grain defect formation in directionally solidified nickel-base superalloys}, booktitle = {Advanced Technologies for Superalloy Affordability as held at the 2000 TMS Annual Meeting}, year = {2000}, pages = {2000}, author = {Tin, S and Pollock, T and Murphy, W} } @booklet {king2000nickel, title = {Nickel-based superalloys exhibiting minimal grain defects}, year = {2000}, note = {US Patent 6,096,141}, author = {King, Warren Tan and Pollock, Tresa M and Zemsky, Christine Louise and Murphy, Wendy Howard} } @conference {pollock2000superalloys, title = {Superalloys 2000}, booktitle = {Ninth International Symposium on Superalloys}, year = {2000}, pages = {2000}, author = {Pollock, TM and Kissinger, RD and Bowman, RR and Green, K} } @article {shi1999deformation, title = {Deformation-induced point defects in NiAl single crystals}, journal = {Intermetallics}, volume = {7}, number = {11}, year = {1999}, pages = {1255{\textendash}1260}, publisher = {Elsevier}, author = {Shi, X and Mahajan, S and Pollock, TM and Arunachalam, VS} } @article {fahrmann1999determination, title = {Determination of matrix and precipitate elastic constants in ($\gamma${\textendash}$\gamma$') Ni-base model alloys, and their relevance to rafting}, journal = {Materials Science and Engineering: A}, volume = {260}, number = {1}, year = {1999}, pages = {212{\textendash}221}, publisher = {Elsevier}, author = {F{\"a}hrmann, M and Hermann, W and F{\"a}hrmann, E and Boegli, A and Pollock, TM and Sockel, HG} } @article {ott1999development, title = {Development and structure of $\alpha$ 2 plates in $\gamma$-based titanium aluminides due to the $\gamma$ to $\alpha$ transformation on heating}, journal = {Scripta materialia}, volume = {40}, number = {8}, year = {1999}, pages = {899{\textendash}904}, publisher = {Pergamon}, author = {Ott, Eric A and Pollock, Tresa M} } @article {biery1999displacement, title = {Displacement Mapping During In-Situ Straining In The SEM}, journal = {MICROSCOPY AND MICROANALYSIS-NEW YORK-}, volume = {5}, number = {2}, year = {1999}, pages = {334{\textendash}335}, publisher = {Springer Science and Media}, author = {Biery, NE and Pollock, TM and Nuhfer, NT and De Graef, M} } @article {shi1999evolution, title = {Evolution of substructures in deformed NiAl single crystals oriented for single slip}, journal = {Philosophical Magazine A}, volume = {79}, number = {7}, year = {1999}, pages = {1555{\textendash}1566}, publisher = {Taylor \& Francis}, author = {Shi, Xiaoli and Mahajan, S and Pollock, TM and Arunachalam, VS} } @article {lu1999low, title = {Low temperature deformation and dislocation substructure of ruthenium aluminide polycrystals}, journal = {Acta materialia}, volume = {47}, number = {3}, year = {1999}, pages = {1035{\textendash}1042}, publisher = {Elsevier}, author = {Lu, DC and Pollock, TM} } @article {harding1999room, title = {Room temperature fatigue response of $\gamma$-TiAl to impact damage}, journal = {Scripta materialia}, volume = {40}, number = {4}, year = {1999}, pages = {445{\textendash}449}, publisher = {Pergamon}, author = {Harding, Trevor S and Jones, J Wayne and Steif, PS and Pollock, TM} } @article {rishel1998cast, title = {Cast structure and property variability in gamma titanium aluminides}, journal = {Intermetallics}, volume = {6}, number = {7}, year = {1998}, pages = {629{\textendash}636}, publisher = {Elsevier}, author = {Rishel, LL and Biery, NE and Raban, R and Gandelsman, VZ and Pollock, TM and Cramb, AW} } @article {pollock1998creep, title = {Creep deformation and the evolution of precipitate morphology in nickel-based single crystals}, journal = {Modelling of Microstructural Evolution in Creep Resistant Materials}, year = {1998}, pages = {1998}, author = {Pollock, TM} } @conference {lu1998low, title = {Low temperature deformation kinetics of ruthenium aluminide alloys}, booktitle = {MRS Proceedings}, volume = {552}, year = {1998}, pages = {KK7{\textendash}11}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, author = {Lu, DC and Pollock, TM} } @article {ott1998microstructural, title = {Microstructural development and creep deformation in equiaxed $\gamma$, $\gamma$+ $\alpha$ 2, and $\gamma$+ $\alpha$ 2+ B2 titanium aluminides}, journal = {Metallurgical and Materials Transactions A}, volume = {29}, number = {3}, year = {1998}, pages = {965{\textendash}978}, publisher = {Springer}, author = {Ott, Eric A and Pollock, Tresa M} } @article {kolluru1998numerical, title = {Numerical modeling of the creep behavior of unidirectional eutectic composites}, journal = {Acta materialia}, volume = {46}, number = {8}, year = {1998}, pages = {2859{\textendash}2876}, publisher = {Elsevier}, author = {Kolluru, Dakshinamurthy V and Pollock, Tresa M} } @article {eow1998rate, title = {Rate sensitivities for low temperature deformation in ruthenium aluminide alloys}, journal = {Scripta materialia}, volume = {38}, number = {7}, year = {1998}, pages = {1065{\textendash}1069}, publisher = {Pergamon}, author = {Eow, K and Lu, D and Pollock, TM} } @article {nystrom1997discontinuous, title = {Discontinuous cellular precipitation in a high-refractory nickel-base superalloy}, journal = {Metallurgical and Materials Transactions A}, volume = {28}, number = {12}, year = {1997}, pages = {2443{\textendash}2452}, publisher = {Springer}, author = {Nystrom, JD and Pollock, TM and Murphy, WH and Garg, A} } @article {paris1997early, title = {Early stages of precipitate rafting in a single crystal Ni Al Mo model alloy investigated by small-angle X-ray scattering and TEM}, journal = {Acta materialia}, volume = {45}, number = {3}, year = {1997}, pages = {1085{\textendash}1097}, publisher = {Pergamon}, author = {Paris, O and Fa, M and Fa, E and Pollock, TM and Fratzl, P and others} } @article {fahrmann1997element, title = {Element partitioning during coarsening of ($\gamma$- $\gamma$') Ni-Al-Mo alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {28}, number = {9}, year = {1997}, pages = {1943{\textendash}1945}, publisher = {Springer}, author = {F{\"a}hrmann, M and F{\"a}hrmann, E and Pollock, TM and Johnson, WC} } @article {faehrmann1997element, title = {Element partitioning during coarsening of ($\{$gamma$\}$$\{$minus$\}$$\{$gamma$\}$$\{$prime$\}$) Ni-Al-Mo alloys}, journal = {Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science}, volume = {28}, number = {9}, year = {1997}, author = {Faehrmann, M and Faehrmann, E and Pollock, TM and Johnson, WC} } @booklet {harding1997impact, title = {Impact damage and fatigue behavior of gamma TiAl}, year = {1997}, publisher = {The Minerals, Metals and Materials Society, Warrendale, PA (United States)}, author = {Harding, TS and Jones, JW and Pollock, TM and Steif, PS and Rubal, MP} } @article {steif1997surface, title = {Surface damage due to impact and fatigue strength reduction in gamma titanium aluminides}, journal = {Minerals, Metals and Materials Society/AIME(USA),}, year = {1997}, pages = {435{\textendash}442}, author = {Steif, PS and Jones, JW and Harding, T and Rubal, MP and Gandelsman, VZ and Biery, N and Pollock, TM} } @article {pollock1996breakdown, title = {The breakdown of single-crystal solidification in high refractory nickel-base alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {27}, number = {4}, year = {1996}, pages = {1081{\textendash}1094}, publisher = {Springer}, author = {Pollock, TM and Murphy, WH} } @conference {shi1996dislocation, title = {Dislocation substructure in NiAl single crystals deformed at ambient temperature}, booktitle = {MRS Proceedings}, volume = {460}, year = {1996}, pages = {493}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, author = {Shi, X and Pollock, TM and Mahajan, S and Arunachalam, VS} } @article {dary1996effects, title = {Effects of environment on the tensile and creep behavior of a low-oxygen orthorhombic-based titanium aluminide, Ti-22 Al-23 Nb}, journal = {Titanium{\textquoteright}95- Science and technology}, year = {1996}, pages = {396{\textendash}403}, author = {Dary, Francois-Charles and Woodard, Shiela A and Pollock, Tresa M} } @article {dary1996effects, title = {Effects of high temperature air and vacuum exposures on the room temperature tensile behavior of the (O+ B2) titanium aluminide Ti-22Al-23Nb}, journal = {Materials Science and Engineering: A}, volume = {208}, number = {2}, year = {1996}, pages = {188{\textendash}202}, publisher = {Elsevier}, author = {Dary, Francois-Charles and Pollock, Tresa M} } @article {fahrmann1996experimental, title = {An experimental study of the role of plasticity in the rafting kinetics of a single crystal Ni-base superalloy}, year = {1996}, author = {F{\"a}hrmann, M and F{\"a}hrmann, E and Paris, O and Fratzl, P and Pollock, TM} } @article {fahrmann1996influence, title = {The influence of microstructure on the measurement of $\gamma$-$\gamma$' lattice mismatch in single-crystal Ni-base superalloys}, journal = {Materials Science and Engineering: A}, volume = {210}, number = {1}, year = {1996}, pages = {8{\textendash}15}, publisher = {Elsevier}, author = {F{\"a}hrmann, M and Wolf, JG and Pollock, TM} } @article {fahrmann1996influence, title = {The influence of microstructure on the measurement of yy{\textquoteright}lattice mismatch in single-crystal Ni-base superalloys}, journal = {Materials Science \& Engineering A}, volume = {1}, number = {210}, year = {1996}, pages = {8{\textendash}15}, author = {F{\"a}hrmann, M and Wolf, JG and Pollock, TM} } @article {pollock1996situ, title = {In-situ observations of crack initiation and growth at notches in cast Ti-48Al-2Cr-2Nb}, journal = {Scripta materialia}, volume = {35}, number = {11}, year = {1996}, pages = {1311{\textendash}1316}, publisher = {Pergamon}, author = {Pollock, TM and Mumm, DR and Muraleedharan, K and Martin, PL} } @article {walston1996renfi, title = {RENfi N6: THIRD GENERATION SINGLE CRYSTAL SUPERALLOY}, year = {1996}, author = {Walston, WS and O{\textquoteright}hara, KS and Ross, EW and Pollock, TM and Murphy, WH} } @conference {pollock1995deformation, title = {DEFORMATION OF NiAl-BASED INTERMETALLICS}, booktitle = {Micromechanics of Advanced Materials: A Symposium in Honor of Professor James CM Li{\textquoteright}s 70th Birthday: Proceedings of a Symposium}, year = {1995}, pages = {205}, publisher = {Minerals, Metals, \& Materials Society}, organization = {Minerals, Metals, \& Materials Society}, author = {Pollock, TM and Kolluru, D} } @article {pollock1995growth, title = {The growth and elevated temperature stability of high refractory nickel-base single crystals}, journal = {Materials Science and Engineering: B}, volume = {32}, number = {3}, year = {1995}, pages = {255{\textendash}266}, publisher = {Elsevier}, author = {Pollock, Tresa M} } @article {li1995new, title = {A new phase in hydrogen-charged Ti 48Al 2Cr 2Nb}, journal = {Scripta metallurgica et materialia}, volume = {32}, number = {7}, year = {1995}, pages = {1009{\textendash}1014}, publisher = {Pergamon}, author = {Li, K and Pollock, TM and Thompson, AW and De Graef, M} } @booklet {walston1995nickel, title = {Nickel-base superalloy and article with high temperature strength and improved stability}, year = {1995}, note = {US Patent 5,455,120}, author = {Walston, William S and Ross, Earl W and Pollock, Tresa M and O{\textquoteright}hara, Kevin S and Murphy, Wendy H} } @article {pollock1994directional, title = {Directional coarsening in nickel-base single crystals with high volume fractions of coherent precipitates}, journal = {Acta Metallurgica et Materialia}, volume = {42}, number = {6}, year = {1994}, pages = {1859{\textendash}1874}, publisher = {Pergamon}, author = {Pollock, TM and Argon, AS} } @article {kitano1994effect, title = {The effect of impurity content on thermally activated deformation in NiAl single crystals}, journal = {Scripta metallurgica et materialia}, volume = {31}, number = {4}, year = {1994}, pages = {397{\textendash}402}, publisher = {Pergamon}, author = {Kitano, K and Pollock, TM and Noebe, RD} } @conference {woodard1994microstructure, title = {Microstructure and Deformation of Ti-22Al-23Nb Orthorhombic-Based Monolithic and Composite Titanium Aluminides}, booktitle = {MRS Proceedings}, volume = {350}, year = {1994}, pages = {279}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, author = {Woodard, Shiela R and Pollock, Tresa M and others} } @article {pollock1993creep, title = {CREEP RESISTANCE OF CMSX-3 NICKEL-BASE SUPERALLOY SINGLE-CRYSTALS (VOL 40, PG 1, 1992)}, journal = {ACTA METALLURGICA ET MATERIALIA}, volume = {41}, number = {7}, year = {1993}, pages = {2253{\textendash}2253}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, author = {Pollock, TM and Argon, AS} } @conference {kitano1993kinetics, title = {The kinetics of low temperature deformation in NiAl single crystals}, booktitle = {Proc first int symp struct intermet, TMS, Warrendale, PA}, year = {1993}, pages = {591{\textendash}599}, author = {Kitano, K and Pollock, TM} } @article {pollock1992creep, title = {Creep resistance of CMSX-3 nickel base superalloy single crystals}, journal = {Acta Metallurgica et Materialia}, volume = {40}, number = {1}, year = {1992}, pages = {1{\textendash}30}, publisher = {Pergamon}, author = {Pollock, TM and Argon, AS} } @article {field1992development, title = {The Development of gamma/ gamma Interfacial Dislocation Networks During Creep in Nickel-Base Superalloys}, journal = {Superalloys 1992}, year = {1992}, pages = {557{\textendash}566}, author = {Field, RD and Pollock, TM and Murphy, WH} } @article {pollock1992grain, title = {Grain defect formation during directional solidification of nickel base single crystals}, journal = {Superalloys 1992}, year = {1992}, pages = {125{\textendash}134}, publisher = {The Minerals, Metals and Materials Society Warrendale, PA}, author = {Pollock, TM and Murphy, WH and Goldman, EH and Uram, DL and Tu, JS} } @article {pollock1992role, title = {The Role of Creep Deformation in Directional Coarsening of gamma{\textquoteright} in Nickel-Base Single Crystals}, journal = {Modeling of Coarsening and Grain Growth}, year = {1992}, pages = {35{\textendash}44}, author = {Pollock, TM and Argon, AS} } @article {thompson1991creep, title = {Creep of $\alpha$ 2+ $\beta$ Titanium Aluminide Alloys}, journal = {ISIJ International}, volume = {31}, number = {10}, year = {1991}, pages = {1139{\textendash}1146}, publisher = {社団法人 日本鉄鋼協会}, author = {THOMPSON, Anthony W and Pollock, Tresa M} } @booklet {pollock1990creep, title = {Creep Resistance of CMSX-3 Nickel Base Superalloy Single Crystals: Experimental Observations}, year = {1990}, publisher = {MIT}, author = {Pollock, TM and Argon, AS} } @booklet {pollock1990creep, title = {Creep Resistance of CMSX-3 Nickel Base Superalloy Single Crystals: Source of Resistance}, year = {1990}, publisher = {MIT}, author = {Pollock, TM and Argon, AS} } @article {pollock1990creep, title = {Creep resistance of nickel-base superalloy single crystals}, journal = {Creep and fracture of engineering materials and structures}, year = {1990}, pages = {287{\textendash}301}, author = {POLLOCK, TRESAM and ARGON, ALIS} } @inbook {pollock1988intermediate, title = {Intermediate temperature creep deformation in CMSX-3 single crystals}, booktitle = {Superalloys 1988}, year = {1988}, pages = {285}, publisher = {TMS Warrendale}, organization = {TMS Warrendale}, author = {Pollock, Tresa M and Argon, AS} } @conference {argon1987phenomenology, title = {Phenomenology and mechanisms of recovery creep}, booktitle = {Proc. 8th Int. Symp. on Metallurgy and Materials Science, RISO National Lab., Roskilde, Denmark}, year = {1987}, pages = {39{\textendash}54}, author = {Argon, AS and Bhattacharya, AK and Pollock, Tresa M} } @article {bird1986flow, title = {Flow localization during plane strain punch stretching of a ferrite-austenite steel}, journal = {Metallurgical Transactions A}, volume = {17}, number = {9}, year = {1986}, pages = {1537{\textendash}1546}, publisher = {Springer}, author = {Bird, JE and Pollock, T and Srivastava, SK} } @article {pollock1984failure, title = {Failure by shear during plane strain stretching of a duplex steel}, journal = {TMS (The Metallurgical Society) Paper Selection;(USA)}, volume = {56}, number = {CONF-840909{\textendash}}, year = {1984}, author = {Pollock, TM and Bird, JE and Srivastava, SK} }