@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 {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 {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 {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 {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 {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 {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 {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 {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} } @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 {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 {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 {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 {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.} } @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.} } @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} } @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 {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 {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 {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 {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.} } @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 {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} } @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} } @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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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} } @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 {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 {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} } @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 {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 {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} } @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 {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 {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 {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 {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 {beyerlein2013interface, title = {Interface-driven microstructure development and ultra high strength of bulk nanostructured Cu-Nb multilayers fabricated by severe plastic deformation}, journal = {Journal of materials research}, volume = {28}, number = {13}, year = {2013}, pages = {1799{\textendash}1812}, publisher = {Cambridge University Press}, author = {Beyerlein, Irene J and Mara, Nathan A and Carpenter, John S and Nizolek, Thomas and Mook, William M and Wynn, Thomas A and McCabe, Rodney J and Mayeur, Jason R and Kang, Keonwook and Zheng, Shijian and others} } @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 {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 {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 {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 {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 {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 {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 {birkel2012rapid, title = {rapid microwave preparation of thermoelectric TiNiSn and TiCoSb half-heusler compounds}, journal = {Chemistry of Materials}, volume = {24}, number = {13}, year = {2012}, pages = {2558{\textendash}2565}, publisher = {American Chemical Society}, author = {Birkel, Christina S and Zeier, Wolfgang G and Douglas, Jason E and Lettiere, Bethany R and Mills, Carolyn E and Seward, Gareth and Birkel, Alexander and Snedaker, Matthew L and Zhang, Yichi and Snyder, G Jeffrey and others} } @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 {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} } @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 {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 {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 {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} } @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} } @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 {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 {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 {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 {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} } @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 {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 {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} } @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 {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 {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 {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 {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 {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} } @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} } @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 {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 {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} } @article {walston2004joint, title = {Joint development of a fourth generation single crystal superalloy}, year = {2004}, author = {Walston, S and Cetel, A and MacKay, R and OHara, K and Duhl, D and Dreshfield, R} } @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 {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 {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} } @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 {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 {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 {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 {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} } @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 {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} }