@article {2386, title = {Design of an alumina forming coating for Nb-base refractory alloys}, journal = {Mater. Des.}, volume = {251}, year = {2025}, pages = {113652}, author = {Holgate, Collin S and Frey, Carolina and Endsley, Melina A and Suzuki, Akane and Levi, Carlos G and Pollock, Tresa M} } @article {2451, title = {High-throughput refractory alloy design for additive manufacturing}, journal = {Materials \& Design}, volume = {259}, year = {2025}, doi = {https://doi.org/10.1016/j.matdes.2025.114911}, author = {Kaitlyn M. Mullin and Ella C. Allgor and Collin S. Holgate and Kirmina Monir and Gareth G. E. Seward and Noah R. Philips and Tresa M. Pollock} } @article {2441, title = {High-throughput refractory alloy design for additive manufacturing}, journal = {Mater. Des.}, volume = {259}, year = {2025}, month = {11/2025}, pages = {114911}, author = {Mullin, Kaitlyn M and Allgor, Ella C and Holgate, Collin S and Monir, Kirmina and Seward, Gareth G E and Philips, Noah R and Pollock, Tresa M} } @article {2411, title = {Modeling the evolution of slip localization: Realization of link to material strength}, journal = {Acta Mater.}, volume = {299}, year = {2025}, pages = {121314}, author = {Ahmadikia, Behnam and Bean, Chris and Stinville, Jean-Charles and Pollock, Tresa M and Beyerlein, Irene J} } @article {2381, title = {Subsurface microstructure effects on surface resolved slip activity}, journal = {J. Mech. Phys. Solids}, volume = {196}, year = {2025}, pages = {106023}, author = {Hestroffer, Jonathan M and Stinville, Jean-Charles and Charpagne, Marie-agathe and Miller, Matthew P and Pollock, Tresa M and Beyerlein, Irene J} } @article {2261, title = {Antiphase boundaries in B2 intermetallics: Proximate structures, formation energies, and chemical stability}, journal = {Phys. Rev. Mater.}, volume = {8}, year = {2024}, month = {Jan}, pages = {013610}, doi = {10.1103/PhysRevMaterials.8.013610}, url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.8.013610}, author = {Mayer, Justin A. and Pollock, Tresa M. and Vamsi, K. V. and Seshadri, Ram} } @article {2361, title = {Machine learning based damage identification in SiC/SiC composites from acoustic emissions using autoencoders}, journal = {Compos. B Eng.}, volume = {287}, year = {2024}, pages = {111802}, author = {Muir, C and Gibson, T and Hilmas, A and Almansour, A S and Sevener, K and Kiser, J D and Pollock, T M and Daly, S and Smith, C} } @article {2296, title = {Quantification of melt pool dynamics and microstructure during simulated additive manufacturing}, journal = {Scr. Mater.}, volume = {245}, year = {2024}, pages = {116036}, author = {Lamb, James and Ochoa, Ruben and Eres-Castellanos, Adriana and Klemm-Toole, Jonah and Echlin, McLean P and Sun, Tao and Fezzaa, Kamel and Clarke, Amy and Pollock, Tresa M} } @article {2351, title = {Role of microstructure on the development of local orientation gradients in polycrystals}, journal = {J. Mater. Res. Technol.}, volume = {33}, year = {2024}, pages = {168{\textendash}179}, author = {Ahmadikia, Behnam and Shadle, Dalton and Stinville, Jean-Charles and Nygren, Kelly E and Kumar, M Arul and Pollock, Tresa M and Miller, Matthew P and Beyerlein, Irene J} } @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 {2281, title = {Surface{\textendash}-subsurface grain structure relationships}, journal = {Acta Mater.}, volume = {266}, year = {2024}, pages = {119660}, author = {Hestroffer, Jonathan M and Stinville, Jean-Charles and Charpagne, Marie-agathe and Miller, Matthew P and Pollock, Tresa M and Beyerlein, Irene J} } @article {2326, title = {Thermal and elastic properties of an A2/B2 refractory high entropy superalloy and its constituent phases}, journal = {Metall. Mater. Trans. A}, volume = {55}, year = {2024}, pages = {2704{\textendash}2717}, author = {Senkov, Oleg N and Kube, Sebastian A and Drazin, John W and Soni, Vishal and Miracle, Daniel B and Butler, Todd M and Pollock, Tresa M and Banerjee, Rajarshi} } @article {1871, title = {Decoupling build orientation-induced geometric and texture effects on the mechanical response of additively manufactured IN625 thin-walled elements}, journal = {Materials Science and Engineering: A}, volume = {870}, year = {2023}, month = {02}, pages = {144826}, doi = {10.1016/j.msea.2023.144826}, author = {Banerjee, Arunima and Rossin, Jeff and He, Mo-Rigen and Musinski, William and Shade, Paul and Cox, Marie and Schwalbach, Edwin and Pollock, Tresa and Hemker, K.} } @article {1866, title = {Dislocation cells in additively manufactured metallic alloys characterized by electron backscatter diffraction pattern sharpness}, journal = {Materials Characterization}, volume = {197}, year = {2023}, month = {03}, pages = {112673}, doi = {10.1016/j.matchar.2023.112673}, author = {Wang, Fulin and Stinville, Jean-Charles and Charpagne, Marie-agathe and Echlin, Mclean and Agnew, Sean and Pollock, Tresa and Graef, Marc and Gianola, Daniel} } @article {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 {1901, title = {Nondestructive quantification of single crystal elasticity for additively manufactured SB-CoNi-10C, IN625, and Ti64}, journal = {NDT \& E International}, volume = {135}, year = {2023}, month = {02}, pages = {102803}, doi = {10.1016/j.ndteint.2023.102803}, author = {Rossin, Jeff and Leser, Patrick and Benzing, Jake and Torbet, Chris and Dillon, Robert and Smith, Stephen and Daly, Samantha and Pollock, Tresa} } @article {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} } @article {1946, title = {Damage Nucleation During Transverse Creep of a Directionally Solidified Ni-based Superalloy}, journal = {Materials Science and Engineering A}, volume = {858}, year = {2022}, month = {09}, pages = {144089}, doi = {10.1016/j.msea.2022.144089}, author = {Cormier, Jonathan and Stinville, Jean-Charles and Mataveli Suave, Lorena and Mauget, Florent and Patrick, Villechaise and Marcin, Lionel and Pollock, Tresa} } @article {1921, title = {Data-driven Bayesian model-based prediction of fatigue crack nucleation in Ni-based superalloys}, journal = {npj Computational Materials}, volume = {8}, year = {2022}, month = {12}, doi = {10.1038/s41524-022-00727-5}, author = {Pinz, Maxwell and Weber, George and Stinville, Jean-Charles and Pollock, Tresa and Ghosh, Somnath} } @article {2026, title = {Development of grain-scale slip activity and lattice rotation fields in Inconel 718}, journal = {Acta Materialia}, volume = {226}, year = {2022}, month = {01}, pages = {117627}, doi = {10.1016/j.actamat.2022.117627}, author = {Hestroffer, Jonathan and Latypov, Marat and Stinville, Jean-Charles and Charpagne, Marie-agathe and Valle, Valery and Miller, Matthew and Pollock, Tresa and Beyerlein, Irene} } @article {2021, title = {Experimental investigation and thermodynamic modelling of the Mg{\textendash}Al-rich region of the Mg{\textendash}Al{\textendash}Sr System}, journal = {International Journal of Materials Research}, volume = {97}, year = {2022}, month = {01}, pages = {422-428}, doi = {10.1515/ijmr-2006-0070}, author = {Cao, Hongbo and Zhu, Jun and Zhang, Chuan and Wu, Kaisheng and Saddock, Nicholas and Jones, J. and Pollock, Tresa and Schmid-Fetzer, Rainer and Chang, Y.} } @article {1956, title = {Heterogeneous slip localization in an additively manufactured 316L stainless steel}, journal = {International Journal of Plasticity}, volume = {159}, year = {2022}, month = {09}, pages = {103436}, doi = {10.1016/j.ijplas.2022.103436}, author = {Bean, Christopher and Wang, Fulin and Charpagne, Marie-agathe and Villechaise, P. and Valle, Valery and Agnew, S.R. and Gianola, D.S. and Pollock, T.m. and Stinville, Jean-Charles} } @article {2011, title = {A high stability B2-containing refractory multi-principal element alloy}, journal = {Acta Materialia}, volume = {229}, year = {2022}, month = {03}, pages = {117767}, doi = {10.1016/j.actamat.2022.117767}, author = {Frey, Carolina and Silverstein, Ravit and Pollock, Tresa} } @article {1981, title = {In Situ X-ray Radiography and Computational Modeling to Predict Grain Morphology in β-Titanium during Simulated Additive Manufacturing}, journal = {Metals}, volume = {12}, year = {2022}, month = {07}, pages = {1217}, doi = {10.3390/met12071217}, author = {Jasien, Chris and Saville, Alec and Becker, Chandler and Klemm-Toole, Jonah and Fezzaa, Kamel and Sun, Tao and Pollock, Tresa and Clarke, Amy} } @article {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 {2006, title = {Observation of bulk plasticity in a polycrystalline titanium alloy by diffraction contrast tomography and topotomography}, journal = {Materials Characterization}, volume = {188}, year = {2022}, month = {04}, pages = {111891}, doi = {10.1016/j.matchar.2022.111891}, author = {Stinville, Jean-Charles and Ludwig, Wolfgang and Callahan, P.G. and Echlin, M.P. and Valle, Valery and Pollock, T.m. and Proudhon, Henry} } @article {1976, title = {Observations of Damage, Defects, and Structuring in Femtosecond Laser Ablated Surfaces}, journal = {Microscopy and Microanalysis}, volume = {28}, year = {2022}, month = {08}, pages = {872-873}, doi = {10.1017/S1431927622003865}, author = {Echlin, Mclean and Polonsky, Andrew and Lenthe, Will and Titus, Mike and Geurts, Remco and Botman, Aurelien and Straw, Marcus and Gumbsch, Peter and Pollock, Tresa} } @article {2001, title = {Orientation dependent plastic localization in the refractory high entropy alloy HfNbTaTiZr at room temperature}, journal = {Materials Science and Engineering: A}, volume = {848}, year = {2022}, month = {05}, pages = {143291}, doi = {10.1016/j.msea.2022.143291}, author = {Charpagne, Marie-agathe and Stinville, Jean-Charles and Wang, Fulin and Philips, Noah and Pollock, T.m.} } @article {1951, title = {On the origins of fatigue strength in crystalline metallic materials}, journal = {Science}, volume = {377}, year = {2022}, month = {09}, pages = {1065-1071}, doi = {10.1126/science.abn0392}, author = {Stinville, Jean-Charles and Charpagne, Marie-agathe and Cervellon, Alice and H{\'e}mery, Samuel and Wang, Fulin and Callahan, P. and Valle, Valery and Pollock, T.} } @article {1811, title = {Single crystal elastic constants of additively manufactured components determined by resonant ultrasound spectroscopy}, journal = {Materials Characterization}, volume = {192}, year = {2022}, pages = {112244}, abstract = {

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

}, issn = {1044-5803}, doi = {https://doi.org/10.1016/j.matchar.2022.112244}, url = {https://www.sciencedirect.com/science/article/pii/S1044580322005265}, author = {Jeff Rossin and Patrick Leser and Kira Pusch and Carolina Frey and Sven C. Vogel and Alec I. Saville and Chris Torbet and Amy J. Clarke and Samantha Daly and Tresa M. Pollock} } @article {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 {2121, title = {Crystallography and elastic anisotropy in fatigue crack nucleation at nickel alloy twin boundaries}, journal = {Journal of the Mechanics and Physics of Solids}, volume = {155}, year = {2021}, month = {06}, pages = {104538}, doi = {10.1016/j.jmps.2021.104538}, author = {Zhang, Xiaoxian and Stinville, Jean-Charles and Pollock, Tresa and Dunne, Fionn} } @article {2111, title = {Damage mechanism identification in composites via machine learning and acoustic emission}, journal = {npj Computational Materials}, volume = {7}, year = {2021}, month = {06}, pages = {95}, doi = {10.1038/s41524-021-00565-x}, author = {Muir, C. and Swaminathan, B. and Almansour, Amjad and Sevener, Kathleen and Smith, C. and Presby, Michael and Kiser, J. and Pollock, T. and Daly, S.} } @article {2186, title = {A Data-Driven Bayesian Model for Predicting Fatigue Crack Nucleation in Polycrystalline Ni-Based Superalloys}, journal = {SSRN Electronic Journal}, year = {2021}, month = {01}, doi = {10.2139/ssrn.3878357}, author = {Pinz, Maxwell and Weber, George and Stinville, Jean-Charles and Pollock, Tresa and Ghosh, Somnath} } @article {1686, title = {Electron backscattered diffraction using a new monolithic direct detector: High resolution and fast acquisition}, journal = {Ultramicroscopy}, volume = {220}, year = {2021}, pages = {113160}, abstract = {

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

}, keywords = {Direct detection, EBSD, Indexing, Inpainting, SEM, Sparse sampling}, issn = {18792723}, doi = {10.1016/j.ultramic.2020.113160}, url = {https://doi.org/10.1016/j.ultramic.2020.113160}, author = {Wang, Fulin and Echlin, Mclean P. and Taylor, Aidan A. and Shin, Jungho and Bammes, Benjamin and Levin, Barnaby D.A. and De Graef, Marc and Pollock, Tresa M. and Gianola, Daniel S.} } @article {2181, title = {A High Stability B2-Containing Refractory Multi-Principal Element Alloy}, journal = {SSRN Electronic Journal}, year = {2021}, month = {01}, doi = {10.2139/ssrn.3965527}, author = {Frey, Carolina and Silverstein, Ravit and Pollock, Tresa} } @article {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 {2156, title = {On the Localization of Plastic Strain in Microtextured Regions of Ti-6Al-4V}, journal = {Acta Materialia}, volume = {204}, year = {2021}, month = {02}, pages = {116492}, doi = {10.1016/j.actamat.2020.116492}, author = {Cappola, Jonathan and Stinville, Jean-Charles and Charpagne, Marie-agathe and Callahan, Patrick and Echlin, Mclean and Pollock, Tresa and Pilchak, Adam and Kasemer, Matthew} } @article {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 {2051, title = {A Multi-modal Data Merging Framework for Correlative Investigation of Strain Localization in Three Dimensions}, journal = {JOM}, volume = {73}, year = {2021}, month = {09}, doi = {10.1007/s11837-021-04894-6}, author = {Charpagne, Marie-agathe and Stinville, Jean-Charles and Polonsky, Andrew and Echlin, M. and Pollock, T.} } @article {2106, title = {Slip localization in Inconel 718: A three-dimensional and statistical perspective}, journal = {Acta Materialia}, volume = {215}, year = {2021}, month = {06}, pages = {117037}, doi = {10.1016/j.actamat.2021.117037}, author = {Charpagne, Marie-agathe and Hestroffer, Jonathan and Polonsky, Andrew and Echlin, M.P. and Texier, Damien and Valle, Valery and Beyerlein, I.J. and Pollock, T.m. and Stinville, Jean-Charles} } @article {2071, title = {Strain Localization and Fatigue Crack Formation at ( 0001 ) Twist Boundaries in Titanium Alloys}, journal = {Acta Materialia}, volume = {219}, year = {2021}, month = {08}, pages = {117227}, doi = {10.1016/j.actamat.2021.117227}, author = {H{\'e}mery, Samuel and Stinville, Jean-Charles and Wang, Fulin and Charpagne, Marie-agathe and Emigh, M.G. and Pollock, T.m. and Valle, Valery} } @conference {1596, title = {3D Characterization of the Columnar-to-Equiaxed Transition in Additively Manufactured Inconel 718}, booktitle = {Superalloys 2020}, year = {2020}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {

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

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

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

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

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

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

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

}, keywords = {Additive manufacturing, Bayesian inference, Elastic constant inversion, Finite element modeling, Recrystallization, Resonance ultrasound spectroscopy}, issn = {1044-5803}, doi = {https://doi.org/10.1016/j.matchar.2020.110501}, url = {https://www.sciencedirect.com/science/article/pii/S1044580320319720}, author = {Jeff Rossin and Brent Goodlet and Chris Torbet and William Musinski and Marie Cox and Jonathan Miller and Michael Groeber and Alexander Mayes and Eric Biedermann and Stephen Smith and Samantha Daly and Tresa Pollock} } @article {1416, title = {Automated and quantitative analysis of plastic strain localization via multi-modal data recombination}, journal = {Materials Characterization}, volume = {163}, year = {2020}, pages = {110245}, issn = {10445803}, doi = {10.1016/j.matchar.2020.110245}, url = {https://linkinghub.elsevier.com/retrieve/pii/S1044580319335569}, author = {Charpagne, M.A. and Stinville, J.C. and Callahan, P.G. and Texier, D. and Chen, Z. and Villechaise, P. and Valle, V. and Pollock, T.m.} } @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 {1411, title = {Direct measurements of slip irreversibility in a nickel-based superalloy using high resolution digital image correlation}, journal = {Acta Materialia}, volume = {186}, year = {2020}, pages = {172{\textendash}189}, abstract = {

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

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

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

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

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

}, keywords = {Additive manufacturing, Crystallography, Grain refinement, Nucleation, Solidification}, issn = {13596454}, doi = {10.1016/j.actamat.2020.09.043}, url = {https://doi.org/10.1016/j.actamat.2020.09.043}, author = {Martin, J. Hunter and Yahata, Brennan and Mayer, Justin and Mone, Robert and Stonkevitch, Ekaterina and Miller, Julie and O{\textquoteright}Masta, Mark R. and Schaedler, Tobias and Hundley, Jacob and Callahan, Patrick and Pollock, Tresa} } @article {1341, title = {Low Cycle Fatigue of Single Crystal γ'-containing Co-based Superalloys at 750 {\textdegree}C}, journal = {Metallurgical and Materials Transactions A}, volume = {51}, year = {2020}, pages = {200{\textendash}213}, abstract = {

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

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

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

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

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

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

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

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

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

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

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

}, isbn = {978-3-030-40562-5}, doi = {10.1007/978-3-030-40562-5_3}, url = {https://doi.org/10.1007/978-3-030-40562-5_3}, author = {Ghosh, Somnath and Weber, George and Pinz, Maxwell and Bagri, Akbar and Pollock, Tresa M. and Lenthe, Will and Stinville, Jean-Charles and Uchic, Michael D. and Woodward, Christopher}, editor = {Ghosh, Somnath and Woodward, Christopher and Przybyla, Craig} } @article {1526, title = {Non-destructive evaluation of 3D microstructure evolution in strontium titanate}, journal = {Journal of Applied Crystallography}, volume = {53}, year = {2020}, pages = {1{\textendash}11}, abstract = {

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

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

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

}, keywords = {fatigue, High Resolution-Digital Image Correlation (HR-DIC), In-situ tensile testing, Non-metallic inclusions (NMIs), Twin boundary}, isbn = {9783030518349}, doi = {10.1007/978-3-030-51834-9}, url = {http://dx.doi.org/10.1007/978-3-030-51834-9_65}, author = {Texier, Damien and Stinville, Jean-Charles and Charpagne, Marie-agathe and Chen, Zhe and Valle, Valery and Villechaise, Patrick and Pollock, Tresa M. and Cormier, Jonathan}, editor = {Tin, Sammy and Hardy, Mark and Clews, Justin and Cormier, Jonathan and Feng, Qiang and Marcin, John and O{\textquoteright}Brien, Chris and Suzuki, Akane} } @article {1561, title = {Structural coupling and magnetic tuning in Mn$_{2}$$_{-}$ₓCoₓP magnetocalorics for thermomagnetic power generation}, journal = {APL Materials}, volume = {8}, year = {2020}, pages = {041106}, abstract = {

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

}, issn = {2166532X}, doi = {10.1063/1.5142000}, url = {https://doi.org/10.1063/1.5142000}, author = {Levin, Emily E. and Bocarsly, Joshua D. and Grebenkemper, Jason H. and Issa, Ramsey and Wilson, Stephen D. and Pollock, Tresa M. and Seshadri, Ram} } @conference {1616, title = {Tuning Strain Localization in Polycrystalline Nickel-Based Superalloys by Thermomechanical Processing}, booktitle = {Superalloys 2020}, year = {2020}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {

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

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

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

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

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

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

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

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

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

}, keywords = {CMA-ES, Distortions, EBSD, Image segmentation, Multi-modal data}, issn = {10445803}, doi = {10.1016/j.matchar.2019.01.033}, url = {https://doi.org/10.1016/j.matchar.2019.01.033}, author = {Charpagne, Marie Agathe and Strub, Florian and Pollock, Tresa M.} } @article {1386, title = {Computational homogenization for multiscale forward modeling of resonant ultrasound spectroscopy of heterogeneous materials}, journal = {Materials Characterization}, volume = {158}, year = {2019}, pages = {109945}, abstract = {

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

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

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

}, url = {http://arxiv.org/abs/1903.02982}, author = {Strub, Florian and Charpagne, Marie-agathe and Pollock, Tresa M.} } @article {1356, title = {Dislocation dynamics in a nickel-based superalloy via in-situ transmission scanning electron microscopy}, journal = {Acta Materialia}, volume = {168}, year = {2019}, pages = {152{\textendash}166}, abstract = {

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

}, keywords = {Dislocations dynamic, In-situ transmission scanning electron microscopy (TSEM), Nickel-based superalloy ren{\'e} 88DT, Plastic localization, STEM detector, Twin boundary}, issn = {13596454}, doi = {10.1016/j.actamat.2018.12.061}, url = {https://doi.org/10.1016/j.actamat.2018.12.061}, author = {Stinville, J. C. and Yao, Eric R. and Callahan, Patrick G. and Shin, Jungho and Wang, Fulin and Echlin, Mclean P. and Pollock, Tresa M. and Gianola, Daniel S.} } @article {1501, title = {In-plane and out-of-plane deformation at the sub-grain scale in polycrystalline materials assessed by confocal microscopy}, journal = {Acta Materialia}, volume = {169}, year = {2019}, pages = {260{\textendash}274}, abstract = {

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

}, keywords = {High Resolution-Digital Image Correlation (HR-DIC), In-situ tensile testing, Laser scanning confocal microscopy (LSCM), Nickel-based polycrystalline superalloy, Strain localization}, issn = {13596454}, doi = {10.1016/j.actamat.2019.03.001}, url = {https://doi.org/10.1016/j.actamat.2019.03.001}, author = {Liu, J. H. and Vanderesse, N. and Stinville, J. C. and Pollock, T. M. and Bocher, P. and Texier, D.} } @article {1521, title = {New frontiers for the materials genome initiative}, journal = {npj Computational Materials}, volume = {5}, year = {2019}, pages = {1{\textendash}23}, abstract = {

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

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

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

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

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

}, keywords = {Focus-ion-beam cross-section (FIB-cross section), Low cycle fatigue, Non-metallic inclusions, Short crack propagation, Superalloy 718DA}, issn = {13596454}, doi = {10.1016/j.actamat.2018.11.051}, author = {Texier, Damien and Stinville, Jean Charles and Echlin, Mclean P. and Pierret, St{\'e}phane and Villechaise, Patrick and Pollock, Tresa M. and Cormier, Jonathan} } @article {1431, title = {Advanced detector signal acquisition and electron beam scanning for high resolution SEM imaging}, journal = {Ultramicroscopy}, volume = {195}, year = {2018}, pages = {93{\textendash}100}, abstract = {

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

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

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

}, keywords = {Chord length distribution, EBSD, Grain size, Microstructure, Principal component analysis}, issn = {10445803}, doi = {10.1016/j.matchar.2018.09.020}, url = {https://doi.org/10.1016/j.matchar.2018.09.020}, author = {Latypov, Marat I. and K{\"u}hbach, Markus and Beyerlein, Irene J. and Stinville, Jean Charles and Toth, Laszlo S. and Pollock, Tresa M. and Kalidindi, Surya R.} } @article {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 {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 {1421, title = {Enhancing thermoelectric properties through control of Nickel Interstitials and phase separation in Heusler/Half-Heusler TiNi1.1Sn composites}, journal = {Materials}, volume = {11}, year = {2018}, pages = {1{\textendash}12}, abstract = {

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

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

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

}, keywords = {Coherent twin boundary, Elastic anisotropy, Fatigue crack initiation at intermediate and high temperature, High resolution digital image correlation, Microstructural effect, Polycrystalline microstructure, Ren{\'e} 88DT polycrystalline superalloy, Strain localization}, issn = {13596454}, doi = {10.1016/j.actamat.2018.03.035}, url = {https://doi.org/10.1016/j.actamat.2018.03.035}, author = {Stinville, Jean Charles and Martin, Etienne and Karadge, Mallikarjun and Ismonov, Shak and Soare, Monica and Hanlon, Tim and Sundaram, Sairam and Echlin, Mclean P. and Callahan, Patrick G. and Lenthe, William C. and Miller, V. M. and Miao, Jiashi and Wessman, Andrew E. and Finlay, Rebecca and Loghin, Adrian and Marte, Judson and Pollock, Tresa M.} } @article {1451, title = {Grain size effects on NiTi shape memory alloy fatigue crack growth}, journal = {Journal of Materials Research}, volume = {33}, year = {2018}, pages = {91{\textendash}107}, abstract = {

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

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

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

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

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

}, keywords = {Discontinuities measurements, High resolution digital image correlation, Ren{\'e} 88DT polycrystalline superalloy, Scanning electron microscopy, Slip band offset, Slip band shearing, Slip system identification, Strain localization}, issn = {13596454}, doi = {10.1016/j.actamat.2018.07.013}, url = {https://doi.org/10.1016/j.actamat.2018.07.013}, author = {Bourdin, F. and Stinville, J. C. and Echlin, M. P. and Callahan, P. G. and Lenthe, W. C. and Torbet, C. J. and Texier, D. and Bridier, F. and Cormier, J. and Villechaise, P. and Pollock, T. M. and Valle, V.} } @article {1491, title = {Microstructure and Property-Based Statistically Equivalent Representative Volume Elements for Polycrystalline Ni-Based Superalloys Containing Annealing Twins}, journal = {Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science}, volume = {49}, year = {2018}, pages = {5727{\textendash}5744}, abstract = {

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

}, issn = {10735623}, doi = {10.1007/s11661-018-4858-y}, url = {https://doi.org/10.1007/s11661-018-4858-y}, author = {Bagri, Akbar and Weber, George and Stinville, Jean Charles and Lenthe, William and Pollock, Tresa and Woodward, Christopher and Ghosh, Somnath} } @article {1321, title = {Rapid Assessment of Oxidation Behavior in Co-Based γ/γ' Alloys}, journal = {Oxidation of Metals}, volume = {90}, year = {2018}, pages = {485{\textendash}498}, keywords = {Cobalt-base superalloys, Combinatorial synthesis, Oxidation, Photostimulated luminescence spectroscopy}, isbn = {0030-770X}, issn = {0030770X}, doi = {10.1007/s11085-018-9849-2}, url = {https://doi.org/10.1007/s11085-018-9849-2}, author = {Stewart, Colin A. and Suzuki, Akane and Pollock, Tresa M. and Levi, Carlos G.} } @article {1176, title = {Transmission Scanning Electron Microscopy: Defect Observations and Image Simulations}, journal = {Ultramicroscopy }, volume = {186}, year = {2018}, chapter = {49}, doi = {https://doi.org/10.1016/j.ultramic.2017.11.004}, author = {Callahan, PG and Stinville, JC and Yao, ER and Echlin, MP and Titus, MS and De Graef, M and Pollock, TM and Gianola, DS} } @article {1211, title = {3D printing of high-strength aluminium alloys}, journal = {Nature}, volume = {549}, year = {2017}, pages = {365{\textendash}369}, doi = {10.1038/nature23894}, author = {Martin, John H. and Yahata, Brennan D. and Hundley, Jacob M. and Mayer, Justin A. and Schaedler, Tobias A. and Pollock, Tresa M.} } @article {1206, title = {Discrete dislocation plasticity analysis of the effect of interfacial diffusion on the creep response of Ni single-crystal superalloys}, journal = {Acta Materialia}, volume = {135}, year = {2017}, pages = {188{\textendash}200}, doi = {10.1016/j.actamat.2017.06.026}, author = {Shishvan, Siamak S. and Mcmeeking, Robert M. and Pollock, Tresa M. and Deshpande, Vikram S.} } @article {1446, title = {Electrically pumped continuous wave quantum dot lasers epitaxially grown on patterned, on-Axis (001) Si}, journal = {Optics Express}, volume = {25}, year = {2017}, pages = {3927{\textendash}3934}, keywords = {III-V on Silicon, Monolithic Integration, Quantum dot lasers, Silicon Photonics}, isbn = {9784885523069}, issn = {08999406}, doi = {10.1364/ol.42.000338}, author = {Norman, Justin and Kennedy, M.J. and Selvidge, Jennifer and Li, Quang and Wan, Yating and Liu, Alan Y. and Callahan, Patrick G. and Echlin, Mclean P. and Pollock, Tresa M. and Lau, Kei May and Gossard, Arthur C. and Bowers, John E.} } @article {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 {1236, title = {Microstructural Statistics for Fatigue Crack Initiation in Polycrystalline Nickel-base Superalloys}, journal = {International Journal of Fracture}, volume = {208}, year = {2017}, pages = {240}, chapter = {221}, doi = {https://doi.org/10.1007/s10704-017-0241-z}, url = {https://link.springer.com/article/10.1007/s10704-017-0241-z}, author = {Stinville, JC and Lenthe, William C and Echlin, MP and Callahan, PG and Texier, Damien and Pollock, TM} } @article {1256, title = {Modelling the elastic properties of bi-continuous composite microstructures captured with TriBeam serial-sectioning}, journal = {Computational Materials Science}, volume = {131}, year = {2017}, pages = {187{\textendash}195}, doi = {10.1016/j.commatsci.2017.01.026}, author = {Mignone, Paul J. and Echlin, Mclean P. and Pollock, Tresa M. and Finlayson, Trevor R. and Riley, Daniel P. and Sesso, Mitchell L. and Franks, George V.} } @article {1196, title = {On Slip Initiation in Equiaxed Alpha/Beta Ti-6Al-4V}, journal = {Acta Materialia}, volume = {136}, year = {2017}, chapter = {288}, doi = {https://doi.org/10.1016/j.actamat.2017.06.059}, url = {https://www.sciencedirect.com/science/article/pii/S1359645417305360?via\%3Dihub}, author = {Kasemer, M and Echlin, MP and Stinville, JC and Pollock, TM and Dawson, P} } @article {1181, title = {Thermoelectric performance and the role of anti-site disorder in the 24-electron Heusler TiFe2Sn}, journal = {Journal of Physics: Condensed Matter}, volume = {29}, year = {2017}, month = {Apr}, pages = {405702}, doi = {10.1088/1361-648x/aa81e7}, author = {Buffon, Malinda L C and Laurita, Geneva and Lamontagne, Leo and Levin, Emily E and Mooraj, Shahryar and Lloyd, Demetrious L and White, Natalie and Pollock, Tresa M and Seshadri, Ram} } @article {1241, title = {Three-dimensional texture visualization approaches: theoretical analysis and examples}, journal = {Journal of Applied Crystallography}, volume = {50}, year = {2017}, month = {Jul}, pages = {430{\textendash}440}, doi = {10.1107/s1600576717001157}, author = {Callahan, Patrick G. and Echlin, Mclean and Pollock, Tresa M. and Singh, Saransh and Graef, Marc De} } @article {1186, title = {Tuning the magnetocaloric response in half-Heusler/Heusler MnNi1 xSb solid solutions}, journal = {Physical Review Materials}, volume = {1}, year = {2017}, doi = {10.1103/physrevmaterials.1.075003}, author = {Levin, Emily E. and Bocarsly, Joshua D. and Wyckoff, Kira E. and Pollock, Tresa M. and Seshadri, Ram} } @article {jorgensen2016bond, title = {Bond coatings with high rumpling resistance: Design and characterization}, journal = {Surface and Coatings Technology}, volume = {300}, year = {2016}, pages = {25{\textendash}34}, publisher = {Elsevier}, author = {Jorgensen, David J and Suzuki, Akane and Lipkin, Don M and Pollock, Tresa M} } @article {stinville2016combined, title = {A combined grain scale elastic{\textendash}plastic criterion for identification of fatigue crack initiation sites in a twin containing polycrystalline nickel-base superalloy}, journal = {Acta Materialia}, volume = {103}, year = {2016}, pages = {461{\textendash}473}, publisher = {Pergamon}, author = {Stinville, JC and Lenthe, WC and Miao, J and Pollock, TM} } @article {buffon2016enhancement, title = {Enhancement of thermoelectric properties in the Nb{\textendash}Co{\textendash}Sn half-Heusler/Heusler system through spontaneous inclusion of a coherent second phase}, journal = {Journal of Applied Physics}, volume = {120}, number = {7}, year = {2016}, pages = {075104}, publisher = {AIP Publishing}, author = {Buffon, Malinda LC and Laurita, Geneva and Verma, Nisha and Lamontagne, Leo and Ghadbeigi, Leila and Lloyd, Demetrious L and Sparks, Taylor D and Pollock, Tresa M and Seshadri, Ram} } @article {echlin2016femtosecond, title = {Femtosecond Laser Damage in Metals and Semiconductors During TriBeam Tomography}, journal = {Microsc. Microanal}, volume = {22}, year = {2016}, pages = {3}, author = {Echlin, MP and Titus, M and Lenthe, WC and Straw, M and Gumbsch, P and Pollock, TM and Fraunhofer, IWM} } @article {echlin2016incipient, title = {Incipient slip and long range plastic strain localization in microtextured Ti-6Al-4V titanium}, journal = {Acta Materialia}, volume = {114}, year = {2016}, pages = {164{\textendash}175}, publisher = {Pergamon}, author = {Echlin, McLean P and Stinville, Jean Charles and Miller, Victoria M and Lenthe, William C and Pollock, Tresa M} } @article {shishvan2016interfacial, title = {Interfacial diffusion in high-temperature deformation of composites: a discrete dislocation plasticity investigation}, journal = {Journal of the Mechanics and Physics of Solids}, year = {2016}, publisher = {Pergamon}, author = {Shishvan, Siamak S and Pollock, Tresa M and McMeeking, Robert M and Deshpande, Vikram S} } @article {douglas2016magnetic, title = {Magnetic hardening and antiferromagnetic/ferromagnetic phase coexistence in Mn 1- x Fe x Ru 2 Sn Heusler solid solutions}, journal = {Physical Review B}, volume = {94}, number = {9}, year = {2016}, pages = {094412}, publisher = {American Physical Society}, author = {Douglas, Jason E and Levin, Emily E and Pollock, Tresa M and Castillo, Juan C and Adler, Peter and Felser, Claudia and Kr{\"a}mer, Stephan and Page, Katharine L and Seshadri, Ram} } @article {verma2016microstructure, title = {Microstructure Evolution of Biphasic TiNi1+ x Sn Thermoelectric Materials}, journal = {Metallurgical and Materials Transactions A}, year = {2016}, pages = {1{\textendash}12}, publisher = {Springer US}, author = {Verma, Nisha and Douglas, Jason E and Kr{\"a}mer, Stephan and Pollock, Tresa M and Seshadri, Ram and Levi, Carlos G} } @article {eggeler2016planar, title = {Planar defect formation in the g' phase during high temperature creep in single crystal CoNi-base superalloys}, journal = {Acta Materialia}, volume = {113}, year = {2016}, pages = {335{\textendash}349}, publisher = {Pergamon}, author = {Eggeler, YM and M{\"u}ller, J and Titus, MS and Suzuki, A and Pollock, TM and Spiecker, E} } @article {lenthe2016prediction, title = {Prediction of Fatigue-Initiating Twin Boundaries in Polycrystalline Nickel Superalloys Informed by TriBeam Tomography}, journal = {Microscopy and Microanalysis}, volume = {22}, number = {S3}, year = {2016}, pages = {1732{\textendash}1733}, publisher = {Cambridge University Press}, author = {Lenthe, William C and Stinville, Jean-Charles and Echlin, McLean P and Pollock, Tresa M} } @article {stinville2016sub, title = {Sub-grain scale digital image correlation by electron microscopy for polycrystalline materials during elastic and plastic deformation}, journal = {Experimental Mechanics}, volume = {56}, number = {2}, year = {2016}, pages = {197{\textendash}216}, publisher = {Springer US}, author = {Stinville, JC and Echlin, MP and Texier, D and Bridier, F and Bocher, P and Pollock, TM} } @article {steuer2015benefits, title = {Benefits of high gradient solidification for creep and low cycle fatigue of AM1 single crystal superalloy}, journal = {Materials Science and Engineering: A}, volume = {645}, year = {2015}, pages = {109{\textendash}115}, publisher = {Elsevier}, author = {Steuer, S and Villechaise, P and Pollock, TM and Cormier, J} } @article {carpenter2015bulk, title = {Bulk texture evolution of nanolamellar Zr{\textendash}Nb composites processed via accumulative roll bonding}, journal = {Acta Materialia}, volume = {92}, year = {2015}, pages = {97{\textendash}108}, publisher = {Pergamon}, author = {Carpenter, JS and Nizolek, T and McCabe, RJ and Knezevic, M and Zheng, SJ and Eftink, BP and Scott, JE and Vogel, SC and Pollock, TM and Mara, NA and others} } @article {titus2015creep, title = {Creep-induced planar defects in L1 2-containing Co-and CoNi-base single-crystal superalloys}, journal = {Acta Materialia}, volume = {82}, year = {2015}, pages = {530{\textendash}539}, publisher = {Pergamon}, author = {Titus, Michael S and Eggeler, Yolita M and Suzuki, Akane and Pollock, Tresa M} } @article {titus2015high, title = {High resolution energy dispersive spectroscopy mapping of planar defects in L1 2-containing co-base superalloys}, journal = {Acta Materialia}, volume = {89}, year = {2015}, pages = {423{\textendash}437}, publisher = {Pergamon}, author = {Titus, Michael S and Mottura, Alessandro and Viswanathan, G Babu and Suzuki, Akane and Mills, Michael J and Pollock, Tresa M} } @article {stinville2015high, title = {High resolution mapping of strain localization near twin boundaries in a nickel-based superalloy}, journal = {Acta Materialia}, volume = {98}, year = {2015}, pages = {29{\textendash}42}, publisher = {Pergamon}, author = {Stinville, JC and Vanderesse, N and Bridier, F and Bocher, P and Pollock, TM} } @booklet {nizolek2015high, title = {High strength bulk metallic nanolaminates}, year = {2015}, publisher = {ASM INT SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA}, author = {Nizolek, Thomas and Avallone, Jaclyn and Pollock, Tresa and Mara, Nathan and Beyerlein, Irene and Scott, Jeffrey} } @article {echlin2015situ, title = {In situ Femtosecond Laser and Argon Ion Beams for 3D Microanalysis using the TriBeam}, journal = {Microscopy and Microanalysis}, volume = {21}, number = {S3}, year = {2015}, pages = {1847{\textendash}1848}, publisher = {Cambridge University Press}, author = {Echlin, MP and Lenthe, WC and Douglas, J and Titus, M and Guerts, R and Straw, M and Pollock, TM} } @article {suzuki2015l12, title = {L12-Strengthened Cobalt-Base Superalloys}, journal = {Annual Review of Materials Research}, volume = {45}, year = {2015}, pages = {345{\textendash}368}, publisher = {Annual Reviews}, author = {Suzuki, Akane and Inui, Haruyuki and Pollock, Tresa M} } @article {lenthe2015quantitative, title = {Quantitative Analysis of Correlated 3D Strontium Titanate Datasets Collected by TriBeam and Diffraction Contrast Tomography}, journal = {Microscopy and Microanalysis}, volume = {21}, number = {S3}, year = {2015}, pages = {2043{\textendash}2044}, publisher = {Cambridge University Press}, author = {Lenthe, WC and Echlin, MP and Syha, M and Trenkle, A and Gumbsch, P and Pollock, TM} } @article {lenthe2015quantitative, title = {Quantitative voxel-to-voxel comparison of TriBeam and DCT strontium titanate three-dimensional data sets}, journal = {Journal of Applied Crystallography}, volume = {48}, number = {4}, year = {2015}, pages = {1034{\textendash}1046}, publisher = {International Union of Crystallography}, author = {Lenthe, William C and Echlin, MP and Trenkle, Andreas and Syha, Melanie and Gumbsch, Peter and Pollock, Tresa M} } @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 {douglas2015three, title = {Three-dimensional multimodal imaging and analysis of biphasic microstructure in a Ti{\textendash}Ni{\textendash}Sn thermoelectric material}, journal = {APL Materials}, volume = {3}, number = {9}, year = {2015}, pages = {096107}, publisher = {AIP Publishing}, author = {Douglas, Jason E and Echlin, McLean P and Lenthe, William C and Seshadri, Ram and Pollock, Tresa M} } @article {stinville2015transverse, title = {Transverse creep of nickel-base superalloy bicrystals}, journal = {Metallurgical and Materials Transactions A}, volume = {46}, number = {6}, year = {2015}, pages = {2516{\textendash}2529}, publisher = {Springer US}, author = {Stinville, JC and Gallup, K and Pollock, TM} } @article {echlin2015tribeam, title = {The TriBeam system: Femtosecond laser ablation in situ SEM}, journal = {Materials Characterization}, volume = {100}, year = {2015}, pages = {1{\textendash}12}, publisher = {Elsevier}, author = {Echlin, McLean P and Straw, Marcus and Randolph, Steven and Filevich, Jorge and Pollock, Tresa M} } @article {steuer2014creep, title = {Creep behavior under isothermal and non-isothermal conditions of AM3 single crystal superalloy for different solutioning cooling rates}, journal = {Materials Science and Engineering: A}, volume = {601}, year = {2014}, pages = {145{\textendash}152}, publisher = {Elsevier}, author = {Steuer, S and Hervier, Z and Thabart, S and Castaing, C and Pollock, TM and Cormier, J} } @article {eggeler2014creep, title = {Creep deformation-induced antiphase boundaries in L1 2-containing single-crystal cobalt-base superalloys}, journal = {Acta Materialia}, volume = {77}, year = {2014}, pages = {352{\textendash}359}, publisher = {Pergamon}, author = {Eggeler, Yolita M and Titus, Michael S and Suzuki, Akane and Pollock, Tresa M} } @article {pollock2014design, title = {Design constraints and higher temperature intermetallic bond coatings}, year = {2014}, author = {Pollock, TM and Jorgensen, D and Jackson, RW and He, M and Suzuki, A and Lipkin, D} } @article {douglas2014nanoscale, title = {Nanoscale structural heterogeneity in Ni-rich half-Heusler TiNiSn}, journal = {Journal of Applied Physics}, volume = {116}, number = {16}, year = {2014}, pages = {163514}, publisher = {AIP Publishing}, author = {Douglas, Jason E and Chater, Philip A and Brown, Craig M and Pollock, Tresa M and Seshadri, Ram} } @conference {suzuki2014oxide, title = {Oxide-assisted crack growth in hold-time low-cycle-fatigue of single-crystal superalloys}, booktitle = {MATEC Web of Conferences}, volume = {14}, year = {2014}, pages = {04004}, publisher = {EDP Sciences}, organization = {EDP Sciences}, author = {Suzuki, Akane and Gao, Yan and Lipkin, Don and Singhal, Anjali and Krug, Matthew and Konitzer, Douglas and Almer, Jonathan and Pollock, Tresa and Bewlay, Bernard} } @article {douglas2014phase, title = {Phase stability and property evolution of biphasic Ti{\textendash}Ni{\textendash}Sn alloys for use in thermoelectric applications}, journal = {Journal of Applied Physics}, volume = {115}, number = {4}, year = {2014}, pages = {043720}, publisher = {AIP Publishing}, author = {Douglas, Jason E and Birkel, Christina S and Verma, Nisha and Miller, Victoria M and Miao, Mao-Sheng and Stucky, Galen D and Pollock, Tresa M and Seshadri, Ram} } @article {nizolek2014processing, title = {Processing and deformation behavior of bulk Cu{\textendash}Nb nanolaminates}, journal = {Metallography, Microstructure, and Analysis}, volume = {3}, number = {6}, year = {2014}, pages = {470{\textendash}476}, publisher = {Springer US}, author = {Nizolek, T and Mara, NA and Beyerlein, IJ and Avallone, JT and Scott, JE and Pollock, TM} } @article {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 {godlewski2013effect, title = {The effect of aging on the relaxation of residual stress in cast aluminum}, journal = {Metallurgical and Materials Transactions A}, volume = {44}, number = {10}, year = {2013}, pages = {4809{\textendash}4818}, publisher = {Springer US}, author = {Godlewski, Larry A and Su, Xuming and Pollock, Tresa M and Allison, John E} } @article {birkel2013improving, title = {Improving the thermoelectric properties of half-Heusler TiNiSn through inclusion of a second full-Heusler phase: microwave preparation and spark plasma sintering of TiNi 1+ x Sn}, journal = {Physical Chemistry Chemical Physics}, volume = {15}, number = {18}, year = {2013}, pages = {6990{\textendash}6997}, publisher = {Royal Society of Chemistry}, author = {Birkel, Christina S and Douglas, Jason E and Lettiere, Bethany R and Seward, Gareth and Verma, Nisha and Zhang, Yichi and Pollock, Tresa M and Seshadri, Ram and Stucky, Galen D} } @article {birkel2013influence, title = {Influence of Ni nanoparticle addition and spark plasma sintering on the TiNiSn{\textendash}Ni system: structure, microstructure, and thermoelectric properties}, journal = {Solid State Sciences}, volume = {26}, year = {2013}, pages = {16{\textendash}22}, publisher = {Elsevier Masson}, author = {Birkel, Christina S and Douglas, Jason E and Lettiere, Bethany R and Seward, Gareth and Zhang, Yichi and Pollock, Tresa M and Seshadri, Ram and Stucky, Galen D} } @article {allison2013integrated, title = {Integrated Computational Materials Engineering (ICME): Implementing ICME in the Aerospace, Automotive, and Maritime Industries}, journal = {A Study Organized by The Minerals, Metals \& Materials Society. The Minerals, Metals \& Materials Society, Warrendale, PA}, volume = {15086}, year = {2013}, author = {Allison, John and Cowles, Brad and DeLoach, John and Pollock, Tresa and Spanos, George} } @article {lenaburg2013outcomes, title = {Outcomes from research collaborations: What are they and how long do they take?}, journal = {MRS bulletin}, volume = {38}, number = {07}, year = {2013}, pages = {526{\textendash}528}, publisher = {Cambridge Univ Press}, author = {Lenaburg, Lubella A and Sciaky, Elizabeth S and Pollock, Tresa M} } @article {titus2012creep, title = {Creep and directional coarsening in single crystals of new $\gamma${\textendash}$\gamma$' cobalt-base alloys}, journal = {Scripta Materialia}, volume = {66}, number = {8}, year = {2012}, pages = {574{\textendash}577}, publisher = {Elsevier}, author = {Titus, Michael S and Suzuki, Akane and Pollock, Tresa M} } @article {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} } @article {madison2012fluid, title = {Fluid flow and defect formation in the three-dimensional dendritic structure of nickel-based single crystals}, journal = {Metallurgical and Materials Transactions A}, volume = {43}, number = {1}, year = {2012}, pages = {369{\textendash}380}, publisher = {Springer}, author = {Madison, J and Spowart, JE and Rowenhorst, DJ and Aagesen, LK and Thornton, K and Pollock, TM} } @article {titus2012high, title = {High Temperature Creep of New L12 Containing Cobalt-Base Superalloys}, journal = {Superalloys 2012}, year = {2012}, pages = {823{\textendash}832}, publisher = {Wiley Online Library}, author = {Titus, Michael S and Suzuki, Akane and Pollock, Tresa M} } @article {saini2012high, title = {High-temperature materials increase efficiency of gas power plants}, journal = {MRS bulletin}, volume = {37}, number = {06}, year = {2012}, pages = {550{\textendash}551}, publisher = {Cambridge University Press}, author = {Saini, Angela and Pollock, Tresa} } @article {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} } @article {pollock2011oxide, title = {Oxide-Assisted Degradation of Ni-Base Single Crystals During Cyclic Loading: the Role of Coatings}, journal = {Journal of the American Ceramic Society}, volume = {94}, number = {s1}, year = {2011}, publisher = {Blackwell Publishing Inc}, author = {Pollock, Tresa M and Laux, Britta and Brundidge, Clinique L and Suzuki, Akane and He, Ming Y} } @article {tsunekane2011single, title = {Single-crystal solidification of new Co{\textendash}Al{\textendash}W-base alloys}, journal = {Intermetallics}, volume = {19}, number = {5}, year = {2011}, pages = {636{\textendash}643}, publisher = {Elsevier}, author = {Tsunekane, Masafumi and Suzuki, Akane and Pollock, Tresa M} } @booklet {pollock20103d, title = {3D simulations for property determination via reconstructed microstructure in nickel-base superalloys.}, year = {2010}, publisher = {Sandia National Laboratories}, author = {Pollock, Tresa M and Thornton, Katsuyo and Rowenhorst, David J and Spowart, Jonathan E and Madison, Jonathan D} } @article {suzuki2010crack, title = {Crack progression during sustained-peak low-cycle fatigue in single-crystal Ni-base superalloy Ren{\'e} N5}, journal = {Metallurgical and Materials Transactions A}, volume = {41}, number = {4}, year = {2010}, pages = {947{\textendash}956}, publisher = {Springer US}, author = {Suzuki, A and Gigliotti, MFX and Hazel, BT and Konitzer, DG and Pollock, TM} } @article {saddock2010grain, title = {Grain-scale creep processes in Mg{\textendash}Al{\textendash}Ca base alloys: Implications for alloy design}, journal = {Scripta Materialia}, volume = {63}, number = {7}, year = {2010}, pages = {692{\textendash}697}, publisher = {Elsevier}, author = {Saddock, ND and Suzuki, A and Jones, JW and Pollock, TM} } @article {madison2010modeling, title = {Modeling fluid flow in three-dimensional single crystal dendritic structures}, journal = {Acta Materialia}, volume = {58}, number = {8}, year = {2010}, pages = {2864{\textendash}2875}, publisher = {Elsevier}, author = {Madison, J and Spowart, J and Rowenhorst, D and Aagesen, LK and Thornton, K and Pollock, TM} } @article {pollock2010new, title = {New Co-based g-g' high-temperature alloys}, journal = {JOM}, volume = {62}, number = {1}, year = {2010}, pages = {58{\textendash}63}, publisher = {Springer}, author = {Pollock, TM and Dibbern, J and Tsunekane, M and Zhu, J and Suzuki, A} } @article {terbush2010partitioning, title = {Partitioning of Solute to the Primary $\alpha$-Mg Phase in Creep-Resistant Mg-Al-Ca{\textendash}Based Cast Alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {41}, number = {9}, year = {2010}, pages = {2435{\textendash}2442}, publisher = {Springer}, author = {TerBush, Jessica R and Saddock, Nicholas D and Jones, J Wayne and Pollock, Tresa M} } @booklet {madison2010permeability, title = {Permeability Determination via 3 D Reconstruction of the Mushy Zone of Nickel-Base Single Cyrstals}, howpublished = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA.[np]. 14-18 Feb}, year = {2010}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA}, author = {Madison, Jonathan and Spowart, Jonathan and Rowenhorst, Dave and Thornton, Katsuyo and Pollock, Tresa} } @article {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} } @article {evans2009mechanism, title = {A mechanism governing oxidation-assisted low-cycle fatigue of superalloys}, journal = {Acta Materialia}, volume = {57}, number = {10}, year = {2009}, pages = {2969{\textendash}2983}, publisher = {Elsevier}, author = {Evans, AG and He, MY and Suzuki, A and Gigliotti, M and Hazel, B and Pollock, TM} } @article {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 {terbush2008dislocation, title = {Dislocation substructures of three die-cast Mg{\textendash}Al{\textendash}Ca-based alloys}, journal = {Scripta Materialia}, volume = {58}, number = {10}, year = {2008}, pages = {914{\textendash}917}, publisher = {Pergamon}, author = {TerBush, JR and Suzuki, Akane and Saddock, ND and Jones, JW and Pollock, TM} } @article {suzuki2008high, title = {High-temperature strength and deformation of $\gamma$/$\gamma$' two-phase Co{\textendash}Al{\textendash}W-base alloys}, journal = {Acta Materialia}, volume = {56}, number = {6}, year = {2008}, pages = {1288{\textendash}1297}, publisher = {Elsevier}, author = {Suzuki, Akane and Pollock, Tresa M} } @article {suzuki2008precipitation, title = {Precipitation strengthening of a Mg-Al-Ca{\textendash}based AXJ530 die-cast alloy}, journal = {Metallurgical and Materials Transactions A}, volume = {39}, number = {3}, year = {2008}, pages = {696{\textendash}702}, publisher = {Springer US}, author = {Suzuki, Akane and Saddock, ND and TerBush, JR and Powell, BR and Jones, JW and Pollock, TM} } @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 {godlewski20072006, title = {2006-01-0319 A Test Method for Quantifying Residual Stress Due to Heat Treatment in Metals}, journal = {SAE TRANSACTIONS}, volume = {115}, number = {5}, year = {2007}, pages = {273}, publisher = {AMERICAN TECHNICAL PUBLISHERS LTD}, author = {Godlewski, LA and Su, X and Allison, JE and Gustafson, P and Pollock, TM} } @article {suzuki2007effect, title = {Effect of Sr additions on the microstructure and strength of a Mg-Al-Ca ternary alloy}, journal = {Metallurgical and Materials Transactions A}, volume = {38}, number = {2}, year = {2007}, pages = {420{\textendash}427}, publisher = {Springer US}, author = {Suzuki, Akane and Saddock, ND and Riester, L and Lara-Curzio, E and Jones, JW and Pollock, TM} } @article {suzuki2007flow, title = {Flow stress anomalies in $\gamma$/$\gamma$' two-phase Co{\textendash}Al{\textendash}W-base alloys}, journal = {Scripta Materialia}, volume = {56}, number = {5}, year = {2007}, pages = {385{\textendash}388}, publisher = {Elsevier}, author = {Suzuki, Akane and DeNolf, Garret C and Pollock, Tresa M} } @conference {suzuki2007high, title = {High Temperature Strength of Co-based gamma/gamma{\textquoteright} Superalloys}, booktitle = {Advanced Intermetallic-Based Alloys(MRS Symposium Proceedings Series Volume 980)}, volume = {980}, year = {2007}, pages = {499{\textendash}504}, author = {Suzuki, Akane and DeNolf, Garret C and Pollock, Tresa M} } @article {cao2007oxidation, title = {Oxidation of ruthenium aluminide-based alloys: The role of microstructure and platinum additions}, journal = {Intermetallics}, volume = {15}, number = {1}, year = {2007}, pages = {34{\textendash}43}, publisher = {Elsevier}, author = {Cao, F and Nandy, TK and Stobbe, D and Pollock, TM} } @booklet {saddock2007permanent, title = {Permanent Mold Casting and Creep Behavior of Mg-4 Al-4 X:(Ca, Ce, La, Sr) Alloys}, year = {2007}, publisher = {SAE Technical Paper}, author = {Saddock, Nicholas D and Suzuki, Akane and TerBush, Jessica R and Jones, J Wayne and Pollock, Tresa M and Zindel, Jake and Allison, John E} } @article {shyam2007small, title = {Small fatigue crack growth in metallic materials: a model and its application to engineering alloys}, journal = {Acta Materialia}, volume = {55}, number = {19}, year = {2007}, pages = {6606{\textendash}6616}, publisher = {Elsevier}, author = {Shyam, Amit and Allison, John E and Szczepanski, Christopher J and Pollock, Tresa M and Jones, J Wayne} } @article {cao2006experimental, title = {Experimental investigation and thermodynamic modelling of the Mg{\textendash}Al-rich region of the Mg{\textendash}Al{\textendash}Sr System}, journal = {Zeitschrift f{\"u}r Metallkunde}, volume = {97}, number = {4}, year = {2006}, pages = {422{\textendash}428}, publisher = {Carl Hanser Verlag}, author = {Cao, Hongbo and Zhu, Jun and Zhang, Chuan and Wu, Kaisheng and Saddock, Nicholas D and Jones, J Wayne and Pollock, Tresa M and Schmid-Fetzer, Rainer and Chang, Y Austin} } @conference {suzuki2006high, title = {High Temperature Strength of Co-based $\gamma$/$\gamma${\textquoteright}Superalloys}, booktitle = {MRS Proceedings}, volume = {980}, year = {2006}, pages = {0980{\textendash}II08}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, author = {Suzuki, Akane and DeNolf, Garret C and Pollock, Tresa M} } @booklet {srolovitz2006knowledge, title = {Knowledge Oriented Materials Engineering of Layered Thermal Barrier Systems (NOMELT)}, year = {2006}, publisher = {DTIC Document}, author = {Srolovitz, David and Hemker, Kevin and Evans, Anthony and Hutchinson, John and Pollock, Tresa and Smith, John} } @conference {saddock2006microstructure, title = {Microstructure and mechanical properties of permanent mold cast Mg-4 A1-4 (Ca, Ce, La, or Sr) ternary alloys}, booktitle = {Symposium on Magnesium Technology 2006 (TMS 12 March 2006 to 16 March 2006)}, year = {2006}, pages = {77{\textendash}82}, publisher = {The Minerals, Metals \& Materials Society (TMS)}, organization = {The Minerals, Metals \& Materials Society (TMS)}, author = {Saddock, Nicholas and Suzuki, Akane and TerBush, Jessica and Heininger, Eric and Zindel, Jacob and Allison, John and Pollock, Tresa and Jones, J} } @article {suzuki2006phase, title = {Phase equilibria in the Mg-Al-Ca ternary system at 773 and 673 K}, journal = {Metallurgical and Materials Transactions A}, volume = {37}, number = {3}, year = {2006}, pages = {975{\textendash}983}, publisher = {Springer}, author = {Suzuki, Akane and Saddock, Nicholas D and Jones, J Wayne and Pollock, Tresa M} } @booklet {godlewski2006test, title = {A test method for quantifying residual stress due to heat treatment in metals}, year = {2006}, publisher = {SAE Technical Paper}, author = {Godlewski, Larry A and Su, Xuming and Allison, John E and Gustafson, Peter and Pollock, Tresa M} } @article {suzuki2005phase, title = {Phase Transformation and Creep of Mg-Al-Ca Based Die-Cast Alloys}, journal = {Essential Readings in Magnesium Technology}, year = {2005}, pages = {291{\textendash}296}, publisher = {John Wiley \& Sons, Inc.}, author = {Suzuki, Akane and Saddock, Nicholas D and Jones, J Wayne and Pollock, Tresa M} } @article {saddock2005solidification, title = {Solidification and Microstructure of Mg-Al-(Ca, Sr, Ce, La) Ternary Alloys}, journal = {Essential Readings in Magnesium Technology}, year = {2005}, pages = {199{\textendash}204}, publisher = {John Wiley \& Sons, Inc.}, author = {Saddock, ND and Suzuki, A and Wu, K and Wildy, SC and Chang, YA and Pollock, TM and Jones, JW} } @article {suzuki2005solidification, title = {Solidification paths and eutectic intermetallic phases in Mg{\textendash}Al{\textendash}Ca ternary alloys}, journal = {Acta Materialia}, volume = {53}, number = {9}, year = {2005}, pages = {2823{\textendash}2834}, publisher = {Elsevier}, author = {Suzuki, A and Saddock, ND and Jones, JW and Pollock, TM} } @conference {shyam2004development, title = {Development of ultrasonic fatigue for rapid, high temperature fatigue studies in turbine engine materials}, booktitle = {10th International Symposium on Superalloys, Champion, PA, September}, year = {2004}, pages = {19{\textendash}23}, author = {Shyam, A and Torbet, CJ and Jha, SK and Larsen, JM and Caton, MJ and Szczepanski, CJ and Pollock, TM and Jones, JW} } @article {suzuki2004structure, title = {Structure and transition of eutectic (Mg, Al) 2 Ca Laves phase in a die-cast Mg{\textendash}Al{\textendash}Ca base alloy}, journal = {Scripta Materialia}, volume = {51}, number = {10}, year = {2004}, pages = {1005{\textendash}1010}, publisher = {Pergamon}, author = {Suzuki, A and Saddock, ND and Jones, JW and Pollock, TM} } @article {pollock2001comparative, title = {A comparative analysis of low temperature deformation in B2 aluminides}, journal = {Materials Science and Engineering: A}, volume = {317}, number = {1}, year = {2001}, pages = {241{\textendash}248}, publisher = {Elsevier}, author = {Pollock, TM and Lu, DC and Shi, X and Eow, K} } @conference {steif2001dynamic, title = {DYNAMIC DEFORMATION AND DAMAGE IN CAST Y-TIAL DURING TAYLOR CYLINDER IMPACT: EXPERIMENTS AND MODEL VALIDATION}, booktitle = {Structural Intermetallics, 2001: ISSI: Proceedings of the Third International Symposium on Structural Intermetallics}, volume = {1}, year = {2001}, pages = {269}, publisher = {Tms}, organization = {Tms}, author = {Steif, PS and Pollock, TM} } @article {smith2001role, title = {The role of impact damage and fatigue strength reduction in gamma titanium aluminide alloys}, journal = {Structural Intermetallics}, year = {2001}, pages = {259{\textendash}268}, author = {Smith, R and Harding, T and Jones, JW and Steif, P and Pollock, TM} } @article {shi1999deformation, title = {Deformation-induced point defects in NiAl single crystals}, journal = {Intermetallics}, volume = {7}, number = {11}, year = {1999}, pages = {1255{\textendash}1260}, publisher = {Elsevier}, author = {Shi, X and Mahajan, S and Pollock, TM and Arunachalam, VS} } @article {fahrmann1999determination, title = {Determination of matrix and precipitate elastic constants in ($\gamma${\textendash}$\gamma$') Ni-base model alloys, and their relevance to rafting}, journal = {Materials Science and Engineering: A}, volume = {260}, number = {1}, year = {1999}, pages = {212{\textendash}221}, publisher = {Elsevier}, author = {F{\"a}hrmann, M and Hermann, W and F{\"a}hrmann, E and Boegli, A and Pollock, TM and Sockel, HG} } @article {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 {harding1999room, title = {Room temperature fatigue response of $\gamma$-TiAl to impact damage}, journal = {Scripta materialia}, volume = {40}, number = {4}, year = {1999}, pages = {445{\textendash}449}, publisher = {Pergamon}, author = {Harding, Trevor S and Jones, J Wayne and Steif, PS and Pollock, TM} } @booklet {harding1997impact, title = {Impact damage and fatigue behavior of gamma TiAl}, year = {1997}, publisher = {The Minerals, Metals and Materials Society, Warrendale, PA (United States)}, author = {Harding, TS and Jones, JW and Pollock, TM and Steif, PS and Rubal, MP} } @article {steif1997surface, title = {Surface damage due to impact and fatigue strength reduction in gamma titanium aluminides}, journal = {Minerals, Metals and Materials Society/AIME(USA),}, year = {1997}, pages = {435{\textendash}442}, author = {Steif, PS and Jones, JW and Harding, T and Rubal, MP and Gandelsman, VZ and Biery, N and Pollock, TM} } @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 {bird1986flow, title = {Flow localization during plane strain punch stretching of a ferrite-austenite steel}, journal = {Metallurgical Transactions A}, volume = {17}, number = {9}, year = {1986}, pages = {1537{\textendash}1546}, publisher = {Springer}, author = {Bird, JE and Pollock, T and Srivastava, SK} } @article {pollock1984failure, title = {Failure by shear during plane strain stretching of a duplex steel}, journal = {TMS (The Metallurgical Society) Paper Selection;(USA)}, volume = {56}, number = {CONF-840909{\textendash}}, year = {1984}, author = {Pollock, TM and Bird, JE and Srivastava, SK} }