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

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

}, keywords = {3D EBSD, Rapid solidification, Superalloy}, issn = {1359-6462}, doi = {https://doi.org/10.1016/j.scriptamat.2023.115770}, url = {https://www.sciencedirect.com/science/article/pii/S1359646223004918}, author = {James Lamb and Kira M. Pusch and Andrew T. Polonsky and St{\'e}phane A.J. Forsik and Ning Zhou and Austin D. Dicus and Remco Geurts and McLean P. Echlin and Tresa M. Pollock} } @article {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 {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 {1831, title = {Perspective: Large Language Models in Applied Mechanics}, journal = {Journal of Applied Mechanics}, volume = {90}, year = {2023}, month = {06}, pages = {1-12}, doi = {10.1115/1.4062773}, author = {Brodnik, Neal and Carton, Samuel and Muir, Caelin and Ghosh, Satanu and Downey, Doug and Echlin, Mclean and Pollock, Tresa and Daly, Samantha} } @article {2016, title = {3D Grain Shape Generation in Polycrystals Using Generative Adversarial Networks}, journal = {Integrating Materials and Manufacturing Innovation}, volume = {11}, year = {2022}, month = {01}, doi = {10.1007/s40192-021-00244-1}, author = {Jangid, Devendra and Brodnik, Neal and Khan, Amil and Goebel, Michael and Echlin, Mclean and Pollock, Tresa and Daly, Samantha and Manjunath, B.} } @article {1911, title = {Adaptable physics-based super-resolution for electron backscatter diffraction maps}, journal = {npj Computational Materials}, volume = {8}, year = {2022}, month = {12}, doi = {10.1038/s41524-022-00924-2}, author = {Jangid, Devendra and Brodnik, Neal and Goebel, Michael and Khan, Amil and Majeti, SaiSidharth and Echlin, Mclean and Daly, Samantha and Pollock, Tresa and Manjunath, B.} } @article {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 {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 {1931, title = {Materials for extreme environments}, journal = {Nature Reviews Materials}, volume = {8}, year = {2022}, month = {11}, doi = {10.1038/s41578-022-00496-z}, author = {Eswarappa Prameela, Suhas and Pollock, Tresa and Raabe, Dierk and Meyers, Marc and Aitkaliyeva, Assel and Chintersingh, Kerri-Lee and Cordero, Zachary and Graham-Brady, Lori} } @article {1971, title = {Merging Machine Learning and TriBeam Tomography for 3D Defect Detection in an AM CoNi-Based Superalloy}, journal = {Microscopy and Microanalysis}, volume = {28}, year = {2022}, month = {08}, pages = {862-863}, doi = {10.1017/S1431927622003828}, author = {Lamb, James and Echlin, Mclean and Polonsky, Andrew and Geurts, Remco and Pusch, Kira and Raeker, Evan and Botman, Aurelien and Torbet, Chris and Pollock, Tresa} } @article {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 {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 {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 {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 {2131, title = {Multimodal 3D Characterization of Voids in Shock-Loaded Tantalum: Implications for Ductile Spallation Mechanisms}, journal = {Acta Materialia}, volume = {215}, year = {2021}, month = {06}, pages = {117057}, doi = {10.1016/j.actamat.2021.117057}, author = {Francis, Toby and Rottmann, Paul and Polonsky, Andrew and Charpagne, Marie-agathe and Echlin, Mclean and Livescu, Veronica and Jones, David and Gray, G. and Graef, Marc and Pollock, Tresa} } @article {2086, title = {A new elastic characterization method for anisotropic bilayer specimens via Bayesian resonant ultrasound spectroscopy}, journal = {Ultrasonics}, volume = {115}, year = {2021}, month = {08}, pages = {106455}, doi = {10.1016/j.ultras.2021.106455}, author = {Goodlet, Brent and Bales, Ben and Pollock, Tresa} } @article {2046, title = {Recent Developments in Femtosecond Laser-Enabled TriBeam Systems}, journal = {JOM}, volume = {73}, year = {2021}, month = {11}, pages = {1-12}, doi = {10.1007/s11837-021-04919-0}, author = {Echlin, Mclean and Polonsky, Andrew and Lamb, James and Geurts, Remco and Randolph, Steven and Botman, Aurelien and Pollock, Tresa} } @article {2151, title = {Rejuvenation of Directionally Solidified and Single-Crystal Nickel-Base Superalloys}, journal = {Metallurgical and Materials Transactions A}, volume = {52}, year = {2021}, month = {03}, doi = {10.1007/s11661-021-06150-7}, author = {Rettberg, Luke and Callahan, P. and Goodlet, Brent and Pollock, T.} } @article {1671, title = {Temperature dependence of single crystal elastic constants in a CoNi-Base alloy: A new methodology}, journal = {Materials Science and Engineering A}, volume = {803}, year = {2021}, pages = {140507}, abstract = {

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

}, keywords = {Bayesian inference, Elastic constants, High-temperature, Resonant ultrasound spectroscopy, Single crystal, Superalloy}, issn = {09215093}, doi = {10.1016/j.msea.2020.140507}, url = {https://doi.org/10.1016/j.msea.2020.140507}, author = {Goodlet, Brent R. and Murray, Sean P. and Bales, Ben and Rossin, Jeff and Torbet, Chris J. and Pollock, Tresa M.} } @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 {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 {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} } @article {1406, title = {Solidification-driven orientation gradients in additively manufactured stainless steel}, journal = {Acta Materialia}, volume = {183}, year = {2020}, pages = {249{\textendash}260}, abstract = {

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

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

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

}, issn = {2166532X}, doi = {10.1063/1.5142000}, url = {https://doi.org/10.1063/1.5142000}, author = {Levin, Emily E. and Bocarsly, Joshua D. and Grebenkemper, Jason H. and Issa, Ramsey and Wilson, Stephen D. and Pollock, Tresa M. and Seshadri, Ram} } @article {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 {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 {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 {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 {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 {1426, title = {Bayesian inference of elastic properties with resonant ultrasound spectroscopy}, journal = {The Journal of the Acoustical Society of America}, volume = {143}, year = {2018}, pages = {71{\textendash}83}, abstract = {

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

}, issn = {0001-4966}, doi = {10.1121/1.5017840}, author = {Bales, Ben and Petzold, Linda and Goodlet, Brent R. and Lenthe, William C. and Pollock, Tresa M.} } @article {1311, title = {Elastic Properties of Novel Co- and CoNi-Based Superalloys Determined through Bayesian Inference and Resonant Ultrasound Spectroscopy}, journal = {Metallurgical and Materials Transactions A}, volume = {49A}, year = {2018}, month = {06/2018}, pages = {2324{\textendash}2339}, issn = {1543-1940}, doi = {10.1007/s11661-018-4575-6}, url = {https://doi.org/10.1007/s11661-018-4575-6}, author = {Goodlet, Brent R and Mills, Leah and Bales, Ben and Charpagne, Marie-agathe and Murray, Sean P and Lenthe, William C and Petzold, Linda and Pollock, Tresa M} } @article {1486, title = {Femtosecond laser rejuvenation of nanocrystalline metals}, journal = {Acta Materialia}, volume = {156}, year = {2018}, pages = {183{\textendash}195}, abstract = {

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

}, keywords = {Femtosecond lasers, Grain boundaries, Nanocrystalline, Rejuvenation}, issn = {13596454}, doi = {10.1016/j.actamat.2018.06.027}, url = {https://doi.org/10.1016/j.actamat.2018.06.027}, author = {Balbus, Glenn H. and Echlin, Mclean P. and Grigorian, Charlette M. and Rupert, Timothy J. and Pollock, Tresa M. and Gianola, Daniel S.} } @article {1456, title = {Microstructure and property based statistically equivalent RVEs for intragranular γ-γ{\textquoteright} microstructures of Ni-based superalloys}, journal = {Acta Materialia}, volume = {157}, year = {2018}, pages = {245{\textendash}258}, abstract = {

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

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

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

}, issn = {10735623}, doi = {10.1007/s11661-018-4858-y}, url = {https://doi.org/10.1007/s11661-018-4858-y}, author = {Bagri, Akbar and Weber, George and Stinville, Jean Charles and Lenthe, William and Pollock, Tresa and Woodward, Christopher and Ghosh, Somnath} } @article {1476, title = {Shearing of γ{\textquoteright} particles in Co-base and Co-Ni-base superalloys}, journal = {Acta Materialia}, volume = {161}, year = {2018}, pages = {99{\textendash}109}, abstract = {

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

}, keywords = {Ab initio calculation, Dislocation creep, Phase field simulation, Precipitation hardening, Stacking fault ribbon}, issn = {13596454}, doi = {10.1016/j.actamat.2018.09.013}, author = {Feng, L. and Lv, D. and Rhein, R. K. and Goiri, J. G. and Titus, M. S. and Van der Ven, A. and Pollock, T. M. and Wang, Y.} } @article {1176, title = {Transmission Scanning Electron Microscopy: Defect Observations and Image Simulations}, journal = {Ultramicroscopy }, volume = {186}, year = {2018}, chapter = {49}, doi = {https://doi.org/10.1016/j.ultramic.2017.11.004}, author = {Callahan, PG and Stinville, JC and Yao, ER and Echlin, MP and Titus, MS and De Graef, M and Pollock, TM and Gianola, DS} } @article {1446, title = {Electrically pumped continuous wave quantum dot lasers epitaxially grown on patterned, on-Axis (001) Si}, journal = {Optics Express}, volume = {25}, year = {2017}, pages = {3927{\textendash}3934}, keywords = {III-V on Silicon, Monolithic Integration, Quantum dot lasers, Silicon Photonics}, isbn = {9784885523069}, issn = {08999406}, doi = {10.1364/ol.42.000338}, author = {Norman, Justin and Kennedy, M.J. and Selvidge, Jennifer and Li, Quang and Wan, Yating and Liu, Alan Y. and Callahan, Patrick G. and Echlin, Mclean P. and Pollock, Tresa M. and Lau, Kei May and Gossard, Arthur C. and Bowers, John E.} } @article {1231, title = {Forward models for extending the mechanical damage evaluation capability of resonant ultrasound spectroscopy}, journal = {Ultrasonics}, volume = {77}, year = {2017}, pages = {183{\textendash}196}, doi = {10.1016/j.ultras.2017.02.002}, author = {Goodlet, B.r. and Torbet, C.j. and Biedermann, E.j. and Jauriqui, L.m. and Aldrin, J.c. and Pollock, T.m.} } @article {1216, title = {Materials response to glancing incidence femtosecond laser ablation}, journal = {Acta Materialia}, volume = {124}, year = {2017}, pages = {46}, chapter = {37}, doi = {https://doi.org/10.1016/j.actamat.2016.10.055}, url = {https://www.sciencedirect.com/science/article/pii/S1359645416308229}, author = {Echlin, MP and Titus, MS and Gumbsch, P and Pollock, TM} } @article {1226, title = {Oxygen evolution on Fe-doped NiO electrocatalysts deposited via microplasma}, journal = {Nanoscale}, volume = {9}, year = {2017}, pages = {15070{\textendash}15082}, doi = {10.1039/c7nr04302c}, author = {Pebley, Andrew C. and Decolvenaere, Elizabeth and Pollock, Tresa M. and Gordon, Michael J.} } @article {rettberg2016detecting, title = {Detecting Recrystallization in a Single Crystal Ni-Base Alloy using Resonant Ultrasound Spectroscopy}, journal = {NDT \& E International}, year = {2016}, publisher = {Elsevier}, author = {Rettberg, LH and Goodlet, BR and Pollock, TM} } @article {buffon2016enhancement, title = {Enhancement of thermoelectric properties in the Nb{\textendash}Co{\textendash}Sn half-Heusler/Heusler system through spontaneous inclusion of a coherent second phase}, journal = {Journal of Applied Physics}, volume = {120}, number = {7}, year = {2016}, pages = {075104}, publisher = {AIP Publishing}, author = {Buffon, Malinda LC and Laurita, Geneva and Verma, Nisha and Lamontagne, Leo and Ghadbeigi, Leila and Lloyd, Demetrious L and Sparks, Taylor D and Pollock, Tresa M and Seshadri, Ram} } @article {pebley2016exchange, title = {Exchange bias and spin glass behavior in biphasic NiFe 2 O 4/NiO thin films}, journal = {Journal of Magnetism and Magnetic Materials}, year = {2016}, publisher = {North-Holland}, author = {Pebley, Andrew C and Fuks, Preston E and Pollock, Tresa M and Gordon, Michael J} } @article {echlin2016femtosecond, title = {Femtosecond Laser Damage in Metals and Semiconductors During TriBeam Tomography}, journal = {Microsc. Microanal}, volume = {22}, year = {2016}, pages = {3}, author = {Echlin, MP and Titus, M and Lenthe, WC and Straw, M and Gumbsch, P and Pollock, TM and Fraunhofer, IWM} } @article {texier2016microstructural, title = {Microstructural features controlling the variability in low-cycle fatigue properties of alloy Inconel 718DA at intermediate temperature}, journal = {Metallurgical and Materials Transactions A}, volume = {47}, number = {3}, year = {2016}, pages = {1096{\textendash}1109}, publisher = {Springer US}, author = {Texier, Damien and G{\'o}mez, Ana Casanova and Pierret, St{\'e}phane and Franchet, Jean-Michel and Pollock, Tresa M and Villechaise, Patrick and Cormier, Jonathan} } @article {titus2015dislocation, title = {Dislocation injection in strontium titanate by femtosecond laser pulses}, journal = {Journal of Applied Physics}, volume = {118}, number = {7}, year = {2015}, pages = {075901}, publisher = {AIP Publishing}, author = {Titus, Michael S and Echlin, McLean P and Gumbsch, Peter and Pollock, Tresa M} } @article {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 {lenthe2015quantitative, title = {Quantitative Analysis of Correlated 3D Strontium Titanate Datasets Collected by TriBeam and Diffraction Contrast Tomography}, journal = {Microscopy and Microanalysis}, volume = {21}, number = {S3}, year = {2015}, pages = {2043{\textendash}2044}, publisher = {Cambridge University Press}, author = {Lenthe, WC and Echlin, MP and Syha, M and Trenkle, A and Gumbsch, P and Pollock, TM} } @article {lenthe2015quantitative, title = {Quantitative voxel-to-voxel comparison of TriBeam and DCT strontium titanate three-dimensional data sets}, journal = {Journal of Applied Crystallography}, volume = {48}, number = {4}, year = {2015}, pages = {1034{\textendash}1046}, publisher = {International Union of Crystallography}, author = {Lenthe, William C and Echlin, MP and Trenkle, Andreas and Syha, Melanie and Gumbsch, Peter and Pollock, Tresa M} } @conference {biedermann2015resonance, title = {Resonance ultrasound spectroscopy forward modeling and inverse characterization of nickel-based superalloys}, booktitle = {41ST ANNUAL REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION: Volume 34}, volume = {1650}, number = {1}, year = {2015}, pages = {835{\textendash}844}, publisher = {AIP Publishing}, organization = {AIP Publishing}, author = {Biedermann, Eric and Jauriqui, Leanne and Aldrin, John C and Goodlet, Brent and Pollock, Tresa and Torbet, Chris and Mazdiyasni, Siamack} } @article {theillard2015sharp, title = {A sharp computational method for the simulation of the solidification of binary alloys}, journal = {Journal of Scientific Computing}, volume = {63}, number = {2}, year = {2015}, pages = {330{\textendash}354}, publisher = {Springer US}, author = {Theillard, Maxime and Gibou, Fr{\'e}d{\'e}ric and Pollock, Tresa} } @article {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 {iyer2014energetics, title = {Energetics and nucleation of point defects in aluminum under extreme tensile hydrostatic stresses}, journal = {Physical Review B}, volume = {89}, number = {1}, year = {2014}, pages = {014108}, publisher = {American Physical Society}, author = {Iyer, Mrinal and Gavini, Vikram and Pollock, Tresa M} } @article {pebley2014microplasma, title = {Microplasma-Based Growth of Biphasic NiFe2O4/NiO Nanogranular Films for Exchange Bias Applications}, journal = {Chemistry of Materials}, volume = {26}, number = {20}, year = {2014}, pages = {6026{\textendash}6032}, publisher = {American Chemical Society}, author = {Pebley, Andrew C and Peek, Alex and Pollock, Tresa M and Gordon, Michael J} } @conference {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 {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} } @conference {gallup2012transverse, title = {Transverse Creep Behavior of Superalloy Bicrystals}, booktitle = {AIP Conference Proceedings}, year = {2012}, publisher = {American Institute of Physics, Ste. 1 NO 1 Melville NY 11747-4502 United States}, organization = {American Institute of Physics, Ste. 1 NO 1 Melville NY 11747-4502 United States}, author = {Gallup, Kaitlin and Pollock, Tresa} } @article {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 {das2009formation, title = {Formation of secondary reaction zone in ruthenium bearing nickel based single crystal superalloys with diffusion aluminide coatings}, journal = {Materials Science and Technology}, volume = {25}, number = {2}, year = {2009}, pages = {300{\textendash}308}, publisher = {Taylor \& Francis}, author = {Das, DK and Gleeson, B and Murphy, KS and Ma, S and Pollock, TM} } @article {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 {heidloff2009structural, title = {Structural stability of platinum-group-metal-modified $\gamma$+ $\gamma$' Ni-base alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {40}, number = {7}, year = {2009}, pages = {1529{\textendash}1540}, publisher = {Springer US}, author = {Heidloff, AJ and Van Sluytman, J and Pollock, TM and Gleeson, B} } @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} } @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 {elliott2004directional, title = {Directional solidification of large superalloy castings with radiation and liquid-metal cooling: a comparative assessment}, journal = {Metallurgical and Materials Transactions A}, volume = {35}, number = {10}, year = {2004}, pages = {3221{\textendash}3231}, publisher = {Springer-Verlag}, author = {Elliott, AJ and Pollock, TM and Tin, S and King, WT and Huang, S-C and Gigliotti, MFX} } @article {cerreta2004symposium, title = {Symposium on Dynamic Deformation: Constitutive Modeling, Grain Size, and Other Effects{\textendash}In Honor of Prof. Ronald W. Armstrong-Dynamic Deformation and Damage in Cast g-TiAl during Taylor Cylinder}, journal = {Metallurgical and Materials Transactions-Series A}, volume = {35}, number = {9}, year = {2004}, pages = {2557{\textendash}2566}, publisher = {Warrendale, PA: Minerals, Metals \& Materials Society; Materials Park, OH: ASM International, c1994-}, author = {Cerreta, E and Gray, GT and Chen, SR and Pollock, TM} } @article {tryon2004thermal, title = {Thermal expansion behavior of ruthenium aluminides}, journal = {Scripta Materialia}, volume = {50}, number = {6}, year = {2004}, pages = {845{\textendash}848}, publisher = {Pergamon}, author = {Tryon, B and Pollock, TM and Gigliotti, MFX and Hemker, K} } @conference {elliott2003defect, title = {Defect reduction in large superalloy castings by liquid-tin assisted solidification.}, booktitle = {PARSONS 2003: Sixth International Charles Parsons Turbine Conference}, year = {2003}, pages = {649{\textendash}661}, author = {Elliott, AJ and Pollock, TM and Tin, S and King, WT and Huang, S-C and Gigliotti, MFX} } @conference {nandy2003mechanical, title = {Mechanical Behavior of Ternary and Quaternary RuAl Alloys}, booktitle = {MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS}, volume = {753}, year = {2003}, pages = {89{\textendash}96}, publisher = {Cambridge Univ Press}, organization = {Cambridge Univ Press}, author = {Nandy, TK and Feng, Q and Banerjee, D and Gigliotti, MFX and Pollock, TM} } @conference {nandy2002mechanical, title = {Mechanical Behavior of Ternary and Quaternary Rual Alloys}, booktitle = {MRS Proceedings}, volume = {753}, year = {2002}, pages = {BB2{\textendash}11}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, author = {Nandy, TK and Feng, Q and Banerjee, D and Gigliotti, MFX and Pollock, TM} } @article {gray2002strain, title = {Strain hardening}, journal = {Intermetallic Compounds-Principles and Practice: Progress, Volume 3}, year = {2002}, pages = {361{\textendash}377}, publisher = {John Wiley \& Sons, Ltd}, author = {Gray, George T and Pollock, Tresa M} } @article {gilchrist2001cast, title = {Cast gamma titanium aluminides for low pressure turbine blades: a design case study for intermetallics}, journal = {Minerals, Metals and Materials Society/AIME, Structural Intermetallics 2001(USA),}, year = {2001}, pages = {3{\textendash}12}, author = {Gilchrist, Alan and Pollock, Tresa M} } @conference {pollock2000superalloys, title = {Superalloys 2000}, booktitle = {Ninth International Symposium on Superalloys}, year = {2000}, pages = {2000}, author = {Pollock, TM and Kissinger, RD and Bowman, RR and Green, K} } @article {rishel1998cast, title = {Cast structure and property variability in gamma titanium aluminides}, journal = {Intermetallics}, volume = {6}, number = {7}, year = {1998}, pages = {629{\textendash}636}, publisher = {Elsevier}, author = {Rishel, LL and Biery, NE and Raban, R and Gandelsman, VZ and Pollock, TM and Cramb, AW} } @article {nystrom1997discontinuous, title = {Discontinuous cellular precipitation in a high-refractory nickel-base superalloy}, journal = {Metallurgical and Materials Transactions A}, volume = {28}, number = {12}, year = {1997}, pages = {2443{\textendash}2452}, publisher = {Springer}, author = {Nystrom, JD and Pollock, TM and Murphy, WH and Garg, A} } @article {steif1997surface, title = {Surface damage due to impact and fatigue strength reduction in gamma titanium aluminides}, journal = {Minerals, Metals and Materials Society/AIME(USA),}, year = {1997}, pages = {435{\textendash}442}, author = {Steif, PS and Jones, JW and Harding, T and Rubal, MP and Gandelsman, VZ and Biery, N and Pollock, TM} } @article {pollock1992grain, title = {Grain defect formation during directional solidification of nickel base single crystals}, journal = {Superalloys 1992}, year = {1992}, pages = {125{\textendash}134}, publisher = {The Minerals, Metals and Materials Society Warrendale, PA}, author = {Pollock, TM and Murphy, WH and Goldman, EH and Uram, DL and Tu, JS} }