@article {2366, title = {Direct electron detection for EBSD of low symmetry \& beam sensitive ceramics}, journal = {Ultramicroscopy}, volume = {268}, year = {2025}, pages = {114079}, abstract = {

Electron backscatter diffraction (EBSD) is a powerful tool for determining the orientations of near-surface grains in engineering materials. However, many ceramics present challenges for routine EBSD data collection and indexing due to small grain sizes, high crack densities, beam and charge sensitivities, low crystal symmetries, and pseudo-symmetric pattern variants. Micro-cracked monoclinic hafnia, tetragonal hafnon, and hafnia/hafnon composites exhibit all such features, and are used in the present work to show the efficacy of a novel workflow based on a direct detecting EBSD sensor and a state-of-the-art pattern indexing approach. At 5 and 10 keV primary beam energies (where beam-induced damage and surface charge accumulation are minimal), the direct electron detector produces superior diffraction patterns with 10x lower doses compared to a phosphor-coupled indirect detector. Further, pseudo-symmetric variant-related indexing errors from a Hough-based approach (which account for at least 4\%-14\% of map areas) are easily resolved by dictionary indexing. In short, the workflow unlocks fundamentally new opportunities to characterize materials historically unsuited for EBSD.

}, keywords = {Beam sensitive materials, Ceramics, Dictionary indexing, Direct electron detection, Electron backscatter diffraction}, author = {Della Ventura, Nicol{\`o} M and Ericks, Andrew R and Echlin, McLean P and Moore, Kalani and Pollock, Tresa M and Begley, Matthew R and Zok, Frank W and De Graef, Marc and Gianola, Daniel S} } @article {2416, title = {Energy-resolved EBSD using a monolithic direct electron detector}, year = {2025}, abstract = {

Accurate quantification of the energy distribution of backscattered electrons (BSEs) contributing to electron backscatter diffraction (EBSD) patterns remains as an active challenge. This study introduces an energy-resolved EBSD methodology based on a monolithic active pixel sensor direct electron detector and an electron-counting algorithm to enable the energy quantification of individual BSEs, providing direct measurements of electron energy spectra within diffraction patterns. Following detector calibration of the detector signal as a function of primary beam energy, measurements using a 12 keV primary beam on Si(100) reveal a broad BSE energy distribution across the diffraction pattern, extending down to 3 keV. Furthermore, an angular dependence in the weighted average BSE energy is observed, closely matching predictions from Monte Carlo simulations. Pixel-resolved energy maps reveal subtle modulations at Kikuchi band edges, offering insights into the backscattering process. By applying energy filtering within spectral windows as narrow as 2 keV centered on the primary beam energy, significant enhancement in pattern clarity and high-frequency detail is observed. Notably, electrons in the 2\–8 keV range, despite having undergone substantial energy loss (\ΔE = 4\–10 keV), still produce Kikuchi patterns. By enabling energy determination at the single-electron level, this approach introduces a versatile tool-set for expanding the quantitative capabilities of EBSD, thereby offering the potential to deepen the understanding of diffraction contrast mechanisms and to advance the precision of crystallographic measurements.

}, author = {Della Ventura, Nicol{\`o} M and Moore, Kalani and Echlin, McLean P and Begley, Matthew R and Pollock, Tresa M and De Graef, Marc and Gianola, Daniel S} } @unpublished {2406, title = {Mining multimodal fatigue data using reasoning foundation models and formalized domain knowledge}, year = {2025}, abstract = {

The scarcity and expense of fatigue data limits optimal design of components and constrains companies to a few well qualified materials when safety-critical applications are concerned. This research investigates different strategies to improve extraction of structured information from unstructured scientific literature\–-to date the largest corpus of fatigue information. Successful generative extraction is within reach considering latest foundation vision and reasoning language model (VLM/RLM) developments. In this work, a schema-based extraction is attempted for which an object-oriented fatigue data schema is designed. The schema provides labels, definitions and type-constraints for the target entities as contextual domain knowledge to the VLM/RLM model. The importance of nuanced target field definitions within the schema and constrained decoding is explored. Furthermore, the schema-based approach is gradually extended to form two agentic language model systems, one which utilizes a step-wise, human-inspired approach to first determine discriminative cues from fatigue S-N diagrams and one further applying dynamic knowledge augmentation. The latter dynamic workflow exploits the synergy of reasoning language models and ontologies by performing logical reasoning and web-search for dynamic knowledge augmentation and hallucination detection. On this rather complex fatigue data extraction task, requiring hierarchical pattern recognition and multimodal extraction, an overall F1-score of 0.82 is achieved, while fields contained in the narrative text modality are extracted with an F1-score of 0.92. The strengths and weaknesses of all models and methodologies are thoroughly discussed and extensions to our workflows are proposed.

}, author = {Mohanty, Jyoti Prakash and Thomas, Akhil and Pollock, Tresa M and Durmaz, Ali Riza} } @article {2376, title = {Non-destructive evaluation of bulk metallic glass components using resonance ultrasound spectroscopy}, journal = {Appl. Mater. Today}, volume = {42}, year = {2025}, pages = {102529}, author = {Kube, Sebastian A and Bordeenithikasem, Punnathat and Ziemke, Patrick and Lamb, James and Rossin, Jeff and Torbet, Chris and Begley, Matthew R and Dillon, R Peter and Pollock, Tresa M} } @article {2391, title = {Orientation-Adaptive Virtual Imaging of Defects using EBSD}, year = {2025}, abstract = {

EBSD is a foundational technique for characterizing crystallographic orientation, phase distribution, and lattice strain. Embedded within EBSD patterns lies latent information on dislocation structures, subtly encoded due to their deviation from perfect crystallinity - a feature often underutilized. Here, a novel framework termed orientation-adaptive virtual apertures (OAVA) is introduced. OAVAs enable the generation of virtual images tied to specific diffraction conditions, allowing the direct visualization of individual dislocations from a single EBSD map. By dynamically aligning virtual apertures in reciprocal space with the local crystallographic orientation, the method enhances contrast from defect-related strain fields, mirroring the principles of diffraction-contrast imaging in TEM, but without sample tilting. The approach capitalizes on the extensive diffraction space captured in a single high-quality EBSD scan, with its effectiveness enhanced by modern direct electron detectors that offer high-sensitivity at low accelerating voltages, reducing interaction volume and improving spatial resolution. We demonstrate that using OAVAs, identical imaging conditions can be applied across a polycrystalline field-of-view, enabling uniform contrast in differently oriented grains. Furthermore, in single-crystal GaN, threading dislocations are consistently resolved. Algorithms for the automated detection of dislocation contrast are presented, advancing defect characterization. By using OAVAs across a wide range of diffraction conditions in GaN, the visibility/invisibility of defects, owing to the anisotropy of the elastic strain field, is assessed and linked to candidate Burgers vectors. Altogether, OAVA offers a new and high-throughput pathway for orientation-specific defect characterization with the potential for automated, large-area defect analysis in single and polycrystalline materials.

}, author = {Della Ventura, Nicol{\`o} M and Lamb, James D and Lenthe, William C and Echlin, McLean P and P{\"u}rstl, Julia T and Trageser, Emily S and Quevedo, Alejandro M and Begley, Matthew R and Pollock, Tresa M and Gianola, Daniel S and De Graef, Marc} } @inbook {2336, title = {3D characterization of defects and microstructure in high density LPBF prints of a CoNi alloy}, booktitle = {The Minerals, Metals \& Materials Series}, series = {The minerals, metals \& materials series}, year = {2024}, pages = {811{\textendash}821}, publisher = {Springer Nature Switzerland}, organization = {Springer Nature Switzerland}, address = {Cham}, author = {Lamb, James D and Raeker, Evan B and Pusch, Kira M and Echlin, McLean P and Forsik, Stephane A J and Zhou, Ning and Dicus, Austin D and Pollock, Tresa M} } @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 {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 {2266, title = {Q-RBSA: High-resolution 3D EBSD map generation using an efficient quaternion transformer network}, journal = {npj Computational Materials}, volume = {10}, year = {2024}, month = {Jan}, doi = {10.1038/s41524-024-01209-6}, author = {Jangid, Devendra K. and Brodnik, Neal R. and Echlin, Mclean P. and Gudavalli, Chandrakanth and Levenson, Connor and Pollock, Tresa M. and Daly, Samantha H. and Manjunath, B. S.} } @inbook {2331, title = {Solidification and crack defect formation on the single melt track scale for high $$\textbackslashupgamma ^\textbackslashprime $$ CoNi-base superalloy variants}, booktitle = {The Minerals, Metals \& Materials Series}, series = {The minerals, metals \& materials series}, year = {2024}, pages = {948{\textendash}957}, publisher = {Springer Nature Switzerland}, organization = {Springer Nature Switzerland}, address = {Cham}, author = {Raeker, Evan B and Pusch, Kira M and Mullin, Kaitlyn M and Lamb, James D and Zhou, Ning and Forsik, Stephane A J and Dicus, Austin D and Kirka, Michael M and Pollock, Tresa M} } @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 {2306, title = {Toward reliable ad-hoc scientific information extraction: A case study on two materials datasets}, year = {2024}, abstract = {

We explore the ability of GPT-4 to perform ad-hoc schema based information extraction from scientific literature. We assess specifically whether it can, with a basic prompting approach, replicate two existing material science datasets, given the manuscripts from which they were originally manually extracted. We employ materials scientists to perform a detailed manual error analysis to assess where the model struggles to faithfully extract the desired information, and draw on their insights to suggest research directions to address this broadly important task.

}, author = {Ghosh, Satanu and Brodnik, Neal R and Frey, Carolina and Holgate, Collin and Pollock, Tresa M and Daly, Samantha and Carton, Samuel} } @article {2321, title = {Understanding the influence of boron in additively manufactured GammaPrint\textregistered-700 CoNi-based superalloy}, journal = {Addit. Manuf.}, volume = {92}, year = {2024}, pages = {104370}, author = {Ren, Qing-Qiang and Raeker, Evan B and Pusch, Kira M and Pollock, Tresa M and Forsik, Stephane A J and Zhou, Ning and Dicus, Austin D and Kirka, Michael M and Poplawsky, Jonathan D} } @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 {1886, title = {Minor Elements and Solidification Cracking During Laser Powder-Bed Fusion of a High γ' CoNi-Base Superalloy}, journal = {Metallurgical and Materials Transactions}, volume = {54}, year = {2023}, month = {02}, pages = {1-14}, doi = {10.1007/s11661-023-06957-6}, author = {Raeker, Evan and Pusch, Kira and Forsik, St{\'e}phane and Zhou, Ning and Dicus, Austin and Ren, Qing-Qiang and Poplawsky, Jonathan and Kirka, M. and Pollock, Tresa} } @article {1901, title = {Nondestructive quantification of single crystal elasticity for additively manufactured SB-CoNi-10C, IN625, and Ti64}, journal = {NDT \& E International}, volume = {135}, year = {2023}, month = {02}, pages = {102803}, doi = {10.1016/j.ndteint.2023.102803}, author = {Rossin, Jeff and Leser, Patrick and Benzing, Jake and Torbet, Chris and Dillon, Robert and Smith, Stephen and Daly, Samantha and Pollock, Tresa} } @article {1831, title = {Perspective: Large Language Models in Applied Mechanics}, journal = {Journal of Applied Mechanics}, volume = {90}, year = {2023}, month = {06}, pages = {1-12}, doi = {10.1115/1.4062773}, author = {Brodnik, Neal and Carton, Samuel and Muir, Caelin and Ghosh, Satanu and Downey, Doug and Echlin, Mclean and Pollock, Tresa and Daly, Samantha} } @article {1851, title = {Perspective: Machine learning in experimental solid mechanics}, journal = {Journal of the Mechanics and Physics of Solids}, volume = {173}, year = {2023}, month = {04}, pages = {105231}, doi = {10.1016/j.jmps.2023.105231}, author = {Brodnik, N.R. and Muir, C. and Tulshibagwale, N. and Rossin, J. and Echlin, M.P. and Hamel, C.M. and Kramer, S.L.B. and Pollock, T.m. and Kiser, J.D. and Smith, C. and Daly, S.H.} } @article {1891, title = {Quantitative Benchmarking of Acoustic Emission Machine Learning Frameworks for Damage Mechanism Identification}, journal = {Integrating Materials and Manufacturing Innovation}, year = {2023}, month = {02}, pages = {1-12}, doi = {10.1007/s40192-023-00293-8}, author = {Muir, C. and Tulshibagwale, N. and Furst, A. and Swaminathan, B. and Almansour, Amjad and Sevener, Kathleen and Presby, Michael and Kiser, J. and Pollock, T. and Daly, S. and Smith, C.} } @conference {1836, title = {Titanium 3D Microstructure for Physics-based Generative Models: A Dataset and Primer}, year = {2023}, month = {07}, author = {Jangid, Devendra and Brodnik, Neal and Echlin, Mclean and Daly, Samantha and Pollock, Tresa and Manjunath, B.} } @article {2016, title = {3D Grain Shape Generation in Polycrystals Using Generative Adversarial Networks}, journal = {Integrating Materials and Manufacturing Innovation}, volume = {11}, year = {2022}, month = {01}, doi = {10.1007/s40192-021-00244-1}, author = {Jangid, Devendra and Brodnik, Neal and Khan, Amil and Goebel, Michael and Echlin, Mclean and Pollock, Tresa and Daly, Samantha and Manjunath, B.} } @article {1911, title = {Adaptable physics-based super-resolution for electron backscatter diffraction maps}, journal = {npj Computational Materials}, volume = {8}, year = {2022}, month = {12}, doi = {10.1038/s41524-022-00924-2}, author = {Jangid, Devendra and Brodnik, Neal and Goebel, Michael and Khan, Amil and Majeti, SaiSidharth and Echlin, Mclean and Daly, Samantha and Pollock, Tresa and Manjunath, B.} } @article {1796, title = {Grain-Scale Stress States in Microtextured Ti64: Implications for Dwell Fatigue}, journal = {Jom}, volume = {74}, year = {2022}, pages = {3709{\textendash}3719}, abstract = {

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

}, isbn = {1183702205}, issn = {15431851}, doi = {10.1007/s11837-022-05423-9}, url = {https://doi.org/10.1007/s11837-022-05423-9}, author = {Wendorf, Joe and Dawson, Paul R. and Pollock, Tresa M.} } @article {1996, title = {Microstructure Evolution and Tensile Properties of a Selectively Laser Melted CoNi-Base Superalloy}, journal = {Metallurgical and Materials Transactions A}, volume = {53}, year = {2022}, month = {05}, doi = {10.1007/s11661-022-06716-z}, author = {Murray, Sean and Raeker, Evan and Pusch, Kira and Frey, Carolina and Torbet, Chris and Zhou, Ning and Forsik, St{\'e}phane and Dicus, Austin and Colombo, Gian and Kirka, M. and Pollock, Tresa} } @article {1991, title = {Scan strategies in EBM-printed IN718 and the physics of bulk 3D microstructure development}, journal = {Materials Characterization}, volume = {190}, year = {2022}, month = {06}, pages = {112043}, doi = {10.1016/j.matchar.2022.112043}, author = {Polonsky, Andrew and Raghavan, Narendran and Echlin, Mclean and Kirka, M. and Dehoff, Ryan and Pollock, Tresa} } @article {1811, title = {Single crystal elastic constants of additively manufactured components determined by resonant ultrasound spectroscopy}, journal = {Materials Characterization}, volume = {192}, year = {2022}, pages = {112244}, abstract = {

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

}, issn = {1044-5803}, doi = {https://doi.org/10.1016/j.matchar.2022.112244}, url = {https://www.sciencedirect.com/science/article/pii/S1044580322005265}, author = {Jeff Rossin and Patrick Leser and Kira Pusch and Carolina Frey and Sven C. Vogel and Alec I. Saville and Chris Torbet and Amy J. Clarke and Samantha Daly and Tresa M. Pollock} } @conference {2061, title = {3D Characterization of the Columnar-to-Equiaxed Transition in Additively Manufactured Inconel 718.}, year = {2021}, month = {09}, doi = {10.2172/1886524}, author = {Polonsky, Andrew and Raghavan, Narendran and Echlin, Mclean and Kirka, Michael and Dehoff, Ryan and Pollock, Tresa} } @article {1741, title = {Bayesian inference of elastic constants and texture coefficients in additively manufactured cobalt-nickel superalloys using resonant ultrasound spectroscopy}, journal = {Acta Materialia}, volume = {220}, year = {2021}, pages = {117287}, abstract = {

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

}, keywords = {Additive manufacturing, Bayesian inference, Parallel computing, Residual stress, Resonance ultrasound spectroscopy, Sequential monte carlo, Texture characterization}, issn = {1359-6454}, doi = {https://doi.org/10.1016/j.actamat.2021.117287}, url = {https://www.sciencedirect.com/science/article/pii/S1359645421006674}, author = {Jeff Rossin and Patrick Leser and Kira Pusch and Carolina Frey and Sean P. Murray and Chris J. Torbet and Stephen Smith and Samantha Daly and Tresa M. Pollock} } @article {2101, title = {Corrigendum to {\textquotedblleft}Defects and 3D structural inhomogeneity in electron beam additively manufactured Inconel 718{\textquotedblright} [Materials Characterization 143 (2018) 171{\textendash}181]}, journal = {Materials Characterization}, volume = {176}, year = {2021}, month = {06}, pages = {111069}, doi = {10.1016/j.matchar.2021.111069}, author = {Polonsky, Andrew and Echlin, Mclean and Lenthe, William and Dehoff, Ryan and Kirka, M. and Pollock, Tresa} } @article {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 {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 {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 {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} } @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 {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 {1576, title = {Growth accidents induced by primary γ{\textquoteright} precipitates in a polycrystalline nickel-based superalloy}, journal = {Scripta Materialia}, volume = {186}, year = {2020}, pages = {1{\textendash}5}, keywords = {3D EBSD, Annealing twin boundaries, Critical recrystallization, Nickel-base superalloy, Recrystallization}, issn = {1359-6462}, doi = {10.1016/j.scriptamat.2020.05.020}, url = {https://doi.org/10.1016/j.scriptamat.2020.05.020}, author = {Charpagne, M A and Polonsky, A T and Echlin, M P and Jacomet, S and De Jaeger, J and De Graef, M and Bozzolo, N and Pollock, T M} } @article {1631, title = {Growth accidents induced by primary γ' precipitates in a polycrystalline nickel-based superalloy}, journal = {Scripta Materialia}, volume = {186}, year = {2020}, month = {09/2020}, pages = {109-113}, abstract = {

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

}, keywords = {3D EBSD, Annealing twin boundaries, Critical recrystallization, Nickel-base superalloy, Recrystallization}, doi = {https://doi.org/10.1016/j.scriptamat.2020.05.020}, url = {https://www.sciencedirect.com/science/article/abs/pii/S1359646220302979$\#$fig0005}, author = {M.A. Charpagne and A.T. Polonsky and M.P. Echlin and S. Jacomet and J. de Jaeger and M. De Graef and N. Bozzolo and T.M. Pollock} } @article {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 {1621, title = {Sustainability through alloy design: Challenges and opportunities}, journal = {Progress in Materials Science}, year = {2020}, pages = {100722}, abstract = {

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

}, keywords = {Aluminum, High Entropy Alloys, Magnesium, Metallurgy, Shape memory alloys, Steel, Superalloys, Sustainability, Titanium}, issn = {00796425}, doi = {10.1016/j.pmatsci.2020.100722}, url = {https://doi.org/10.1016/j.pmatsci.2020.100722}, author = {Cann, Jaclyn L. and De Luca, Anthony and Dunand, David C. and Dye, David and Miracle, Daniel B. and Oh, Hyun Seok and Olivetti, Elsa A. and Pollock, Tresa M. and Poole, Warren J. and Yang, Rui and Tasan, C. Cem} } @article {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.} } @article {1506, title = {Alloy Design and Processing Design of Magnesium Alloys Using 2nd Phases}, journal = {JOM}, volume = {71}, year = {2019}, pages = {2219{\textendash}2226}, abstract = {

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

}, issn = {15431851}, doi = {10.1007/s11837-019-03482-z}, url = {https://doi.org/10.1007/s11837-019-03482-z}, author = {Decker, R. F. and Berman, T. D. and Miller, V. M. and Jones, J. W. and Pollock, T. M. and LeBeau, S. E.} } @article {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 {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 {1326, title = {Defects and 3D structural inhomogeneity in electron beam additively manufactured Inconel 718}, journal = {Materials Characterization}, volume = {143}, year = {2018}, pages = {171{\textendash}181}, abstract = {

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

}, keywords = {Additive manufacturing, Electron beam melting, Lack of fusion, Microstructure, Tomography}, issn = {10445803}, doi = {10.1016/j.matchar.2018.02.020}, author = {Polonsky, Andrew T. and Echlin, Mclean P. and Lenthe, William C. and Dehoff, Ryan R. and Kirka, Michael M. and Pollock, Tresa M.} } @article {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 {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 {1481, title = {Prediction of tensile stiffness and strength of Ti-6Al-4V using instantiated volume elements and crystal plasticity}, journal = {Acta Materialia}, volume = {157}, year = {2018}, pages = {21{\textendash}32}, abstract = {

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

}, keywords = {Crystal plasticity finite element, Stiffness, Titanium, Volume element size, Yield detection}, issn = {13596454}, doi = {10.1016/j.actamat.2018.07.011}, url = {https://doi.org/10.1016/j.actamat.2018.07.011}, author = {Chatterjee, Kamalika and Echlin, Mclean P. and Kasemer, Matthew and Callahan, Patrick G. and Pollock, Tresa M. and Dawson, Paul} } @article {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 {1206, title = {Discrete dislocation plasticity analysis of the effect of interfacial diffusion on the creep response of Ni single-crystal superalloys}, journal = {Acta Materialia}, volume = {135}, year = {2017}, pages = {188{\textendash}200}, doi = {10.1016/j.actamat.2017.06.026}, author = {Shishvan, Siamak S. and Mcmeeking, Robert M. and Pollock, Tresa M. and Deshpande, Vikram S.} } @article {1261, title = {Interfacial diffusion in high-temperature deformation of composites: A discrete dislocation plasticity investigation}, journal = {Journal of the Mechanics and Physics of Solids}, volume = {98}, year = {2017}, pages = {330{\textendash}349}, doi = {10.1016/j.jmps.2016.09.002}, author = {Shishvan, Siamak S. and Pollock, Tresa M. and Mcmeeking, Robert M. and Deshpande, Vikram S.} } @article {1226, title = {Oxygen evolution on Fe-doped NiO electrocatalysts deposited via microplasma}, journal = {Nanoscale}, volume = {9}, year = {2017}, pages = {15070{\textendash}15082}, doi = {10.1039/c7nr04302c}, author = {Pebley, Andrew C. and Decolvenaere, Elizabeth and Pollock, Tresa M. and Gordon, Michael J.} } @article {1201, title = {Reconstruction of Laser-Induced Surface Topography from Electron Backscatter Diffraction Patterns}, journal = {Microscopy and Microanalysis}, volume = {23}, year = {2017}, pages = {730{\textendash}740}, doi = {10.1017/s1431927617012326}, author = {Callahan, Patrick G. and Echlin, Mclean P. and Pollock, Tresa M. and Graef, Marc De} } @article {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 {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 {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 {callahan2015determination, title = {Determination of Surface Topography from Laser Ablation using EBSD}, journal = {Microscopy and Microanalysis}, volume = {21}, number = {S3}, year = {2015}, pages = {2369{\textendash}2370}, publisher = {Cambridge University Press}, author = {Callahan, PG and Echlin, MP and Pollock, TM and De Graef, M} } @article {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 {rhein2015role, title = {Role of vibrational and configurational excitations in stabilizing the L 1 2 structure in Co-rich Co-Al-W alloys}, journal = {Physical Review B}, volume = {92}, number = {17}, year = {2015}, pages = {174117}, publisher = {American Physical Society}, author = {Rhein, Robert K and Dodge, Philip C and Chen, Min-Hua and Titus, Michael S and Pollock, Tresa M and Van der Ven, Anton} } @article {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 {adharapurapu2014combinatorial, title = {A combinatorial investigation of palladium and platinum additions to $\beta$-NiAl overlay coatings}, journal = {Acta Materialia}, volume = {77}, year = {2014}, pages = {379{\textendash}393}, publisher = {Pergamon}, author = {Adharapurapu, Raghavendra R and Zhu, Jun and Dheeradhada, Voramon S and Lipkin, Don M and Pollock, Tresa M} } @article {berman2014effect, title = {Effect of Microstructure on Deformation and Fracture of Thixomolded and Thermomechanically Processed AZ61}, journal = {Magnesium Technology 2014}, year = {2014}, pages = {161{\textendash}166}, publisher = {John Wiley \& Sons, Inc.}, author = {Berman, TD and Donlon, W and Decker, R and Pollock, TM and Jones, JW} } @article {adharapurapu2014effective, title = {Effective Hf-Pd Co-doped $\beta$-NiAl (Cr) coatings for single-crystal superalloys}, journal = {Acta Materialia}, volume = {76}, year = {2014}, pages = {449{\textendash}462}, publisher = {Pergamon}, author = {Adharapurapu, Raghavendra R and Zhu, Jun and Dheeradhada, Voramon S and Lipkin, Don M and Pollock, Tresa M} } @article {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} } @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 {birkel2013improving, title = {Improving the thermoelectric properties of half-Heusler TiNiSn through inclusion of a second full-Heusler phase: microwave preparation and spark plasma sintering of TiNi 1+ x Sn}, journal = {Physical Chemistry Chemical Physics}, volume = {15}, number = {18}, year = {2013}, pages = {6990{\textendash}6997}, publisher = {Royal Society of Chemistry}, author = {Birkel, Christina S and Douglas, Jason E and Lettiere, Bethany R and Seward, Gareth and Verma, Nisha and Zhang, Yichi and Pollock, Tresa M and Seshadri, Ram and Stucky, Galen D} } @article {birkel2013influence, title = {Influence of Ni nanoparticle addition and spark plasma sintering on the TiNiSn{\textendash}Ni system: structure, microstructure, and thermoelectric properties}, journal = {Solid State Sciences}, volume = {26}, year = {2013}, pages = {16{\textendash}22}, publisher = {Elsevier Masson}, author = {Birkel, Christina S and Douglas, Jason E and Lettiere, Bethany R and Seward, Gareth and Zhang, Yichi and Pollock, Tresa M and Seshadri, Ram and Stucky, Galen D} } @article {allison2013integrated, title = {Integrated Computational Materials Engineering (ICME): Implementing ICME in the Aerospace, Automotive, and Maritime Industries}, journal = {A Study Organized by The Minerals, Metals \& Materials Society. The Minerals, Metals \& Materials Society, Warrendale, PA}, volume = {15086}, year = {2013}, author = {Allison, John and Cowles, Brad and DeLoach, John and Pollock, Tresa and Spanos, George} } @article {berman2013microstructure, title = {Microstructure Characterization of Weakly Textured and Fine Grained AZ61 Sheet}, journal = {Magnesium Technology 2013}, year = {2013}, pages = {113{\textendash}118}, publisher = {Wiley Online Library}, author = {Berman, TD and Donlon, W and Hung, CK and Milligan, P and Decker, R and Pollock, TM and Jones, JW} } @article {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 {berman2012microstructure, title = {Microstructure Modification and Deformation Behavior of Fine-Grained AZ61 Sheet Produced by Thixomolding and Thermomechanical Processing (TTMP)}, journal = {Magnesium Technology 2012}, year = {2012}, pages = {339{\textendash}344}, publisher = {John Wiley \& Sons, Inc.}, author = {Berman, TD and Donlon, William and Miller, VM and Decker, R and Huang, J and Pollock, TM and Jones, JW} } @article {birkel2012rapid, title = {rapid microwave preparation of thermoelectric TiNiSn and TiCoSb half-heusler compounds}, journal = {Chemistry of Materials}, volume = {24}, number = {13}, year = {2012}, pages = {2558{\textendash}2565}, publisher = {American Chemical Society}, author = {Birkel, Christina S and Zeier, Wolfgang G and Douglas, Jason E and Lettiere, Bethany R and Mills, Carolyn E and Seward, Gareth and Birkel, Alexander and Snedaker, Matthew L and Zhang, Yichi and Snyder, G Jeffrey and others} } @conference {berman2012structure, title = {Structure Evolution in AZ 61 L along a Fine-Grain Sheet Processing Path}, booktitle = {AIP Conference Proceedings}, year = {2012}, publisher = {American Institute of Physics, Ste. 1 NO 1 Melville NY 11747-4502 United States}, organization = {American Institute of Physics, Ste. 1 NO 1 Melville NY 11747-4502 United States}, author = {Berman, Tracy and Donlon, William and Miller, Victoria and Huang, Jack and Decker, Ray and Jones, Wayne and Pollock, Tresa} } @article {berman2011microstructure, title = {Microstructure Evolution in AZ61L During TTMP and Subsequent Annealing Treatments}, journal = {Magnesium Technology 2011}, year = {2011}, pages = {599{\textendash}603}, publisher = {John Wiley \& Sons, Inc.}, author = {Berman, TD and Donlon, W and Decker, R and Huang, J and Pollock, TM and Jones, JW} } @booklet {adharapurapu2010high, title = {High-Temperature Cyclic Oxidation of Pd/Pt-Modified Nial Bond Coats}, howpublished = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA.[np]. 14-18 Feb}, year = {2010}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA}, author = {Adharapurapu, Raghavendra and Widrevitz, Dan and Zhu, Jun and Lipkin, Don and Dheeradhada, Voroman and Pollock, Tresa} } @booklet {huang2010mechanical, title = {On Mechanical Properties and Microstructures of TTMP Wrought Mg Alloys}, howpublished = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA.[np]. 14-18 Feb}, year = {2010}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 USA}, author = {Huang, Jack and Arbel, Tamir and Ligeski, Laura and McCaffrey, Jesse and Kulkarni, Sanjay and Jones, J and Pollock, Tresa and Decker, Raymond and LeBeau, Steve} } @article {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 {das2009femtosecond, title = {Femtosecond laser machining of cooling holes in thermal barrier coated CMSX4 superalloy}, journal = {Journal of Materials Processing Technology}, volume = {209}, number = {15}, year = {2009}, pages = {5661{\textendash}5668}, publisher = {Elsevier}, author = {Das, Dipak K and Pollock, Tresa M} } @article {das2009formation, title = {Formation of secondary reaction zone in ruthenium bearing nickel based single crystal superalloys with diffusion aluminide coatings}, journal = {Materials Science and Technology}, volume = {25}, number = {2}, year = {2009}, pages = {300{\textendash}308}, publisher = {Taylor \& Francis}, author = {Das, DK and Gleeson, B and Murphy, KS and Ma, S and Pollock, TM} } @conference {white2009time, title = {TIME DOMAIN TERAHERTZ NON-DESTRUCTIVE EVALUATION OF AEROTURBINE BLADE THERMAL BARRIER COATINGS}, booktitle = {REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION: Proceedings of the 35th Annual Review of Progress in Quantitative Nondestructive Evaluation}, volume = {1096}, number = {1}, year = {2009}, pages = {434{\textendash}439}, publisher = {AIP Publishing}, organization = {AIP Publishing}, author = {White, Jeffrey and Fichter, G and Chernovsky, A and Whitaker, John F and Das, D and Pollock, Tresa M and Zimdars, David} } @article {mcdonald2008approaching, title = {Approaching non-destructive surface chemical analysis of CMSX-4 superalloy with double-pulsed laser induced breakdown spectroscopy}, journal = {Spectrochimica Acta Part B: Atomic Spectroscopy}, volume = {63}, number = {5}, year = {2008}, pages = {561{\textendash}565}, publisher = {Elsevier}, author = {McDonald, Joel P and Das, Dipak K and Nees, John A and Pollock, Tresa M and Yalisove, Steven M} } @article {das2008depth, title = {Depth-profiling study of a thermal barrier coated superalloy using femtosecond laser-induced breakdown spectroscopy}, journal = {Spectrochimica Acta Part B: Atomic Spectroscopy}, volume = {63}, number = {1}, year = {2008}, pages = {27{\textendash}36}, publisher = {Elsevier}, author = {Das, DK and McDonald, JP and Yalisove, SM and Pollock, TM} } @article {das2008detection, title = {Detection of a marker layer in a 7YSZ thermal barrier coating by femtosecond laser-induced breakdown spectroscopy}, journal = {Surface and Coatings Technology}, volume = {202}, number = {16}, year = {2008}, pages = {3940{\textendash}3946}, publisher = {Elsevier}, author = {Das, Dipak K and McDonald, Joel P and Levi, Carlos G and Yalisove, Steve M and Pollock, Tresa M} } @article {das2008femtosecond, title = {Femtosecond pulsed laser damage characteristics of 7\% Y2O3-ZrO2 thermal barrier coating}, journal = {Applied Physics A}, volume = {91}, number = {3}, year = {2008}, pages = {421{\textendash}428}, publisher = {Springer}, author = {Das, DK and McDonald, JP and Yalisove, SM and Pollock, TM} } @article {das2008formation, title = {Formation of secondary reaction zones in diffusion aluminide-coated Ni-base single-crystal superalloys containing ruthenium}, journal = {Metallurgical and Materials Transactions A}, volume = {39}, number = {7}, year = {2008}, pages = {1647{\textendash}1657}, publisher = {Springer}, author = {Das, Dipak K and Murphy, Kenneth S and Ma, Shuwei and Pollock, Tresa M} } @article {husseini2008mapping, title = {Mapping single-crystal dendritic microstructure and defects in nickel-base superalloys with synchrotron radiation}, journal = {Acta Materialia}, volume = {56}, number = {17}, year = {2008}, pages = {4715{\textendash}4723}, publisher = {Pergamon}, author = {Husseini, Naji S and Kumah, Divine P and Jian, Z Yi and Torbet, Christopher J and Arms, Dohn A and Dufresne, Eric M and Pollock, Tresa M and Jones, J Wayne and Clarke, Roy} } @conference {white2008time, title = {Time-domain terahertz mapping of thickness and degradation of aircraft turbine blade thermal barrier coatings}, booktitle = {Conference on Lasers and Electro-Optics}, year = {2008}, pages = {CThN7}, publisher = {Optical Society of America}, organization = {Optical Society of America}, author = {White, Jeffrey and Fichter, G and Chernovsky, A and Zimdars, David A and Whitaker, John F and Das, D and Pollock, Tresa M} } @article {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 {kulkarni2007ternary, title = {Ternary diffusion in a RuAl-NiAl couple}, journal = {Journal of Phase Equilibria and Diffusion}, volume = {28}, number = {6}, year = {2007}, pages = {503{\textendash}509}, publisher = {Springer US}, author = {Kulkarni, KN and Tryon, B and Pollock, TM and Dayananda, MA} } @article {wu2006grain, title = {Grain-scale strain mapping for analysis of slip activity in polycrystalline B2 RuAl}, journal = {Philosophical Magazine}, volume = {86}, number = {25-26}, year = {2006}, pages = {3995{\textendash}4008}, publisher = {Taylor \& Francis}, author = {Wu, A and De Graef, M and Pollock, TM} } @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} } @article {nandy2006microstructure, title = {Microstructure and properties of blended Mg- Al alloys fabricated by semisolid processing}, journal = {Metallurgical and Materials Transactions A}, volume = {37}, number = {12}, year = {2006}, pages = {3725{\textendash}3736}, publisher = {Springer}, author = {Nandy, TK and Messing, Rebecca M and Jones, J Wayne and Pollock, Tresa M and Walukas, DM and Decker, RF} } @article {das2006qualitative, title = {Qualitative Characterization of a Thermal Barrier Coating System Using Femtosecond Laser-Induced Breakdown Spectroscopy}, journal = {MATERIALS SCIENCE AND TECHNOLOGY-ASSOCIATION FOR IRON AND STEEL TECHNOLOGY-}, volume = {5}, year = {2006}, pages = {621}, publisher = {ASSOCIATION FO IRON AND STEEL INDUSTRY}, author = {Das, DK and McDonald, JP and Yalisove, SM and Pollock, TM} } @article {walston2004joint, title = {Joint development of a fourth generation single crystal superalloy}, year = {2004}, author = {Walston, S and Cetel, A and MacKay, R and OHara, K and Duhl, D and Dreshfield, R} } @article {lu2004transmission, title = {Transmission electron microscopy study of complex planar faults in Ru{\textendash}Al{\textendash}0.5 at.\% B}, journal = {Philosophical Magazine}, volume = {84}, number = {22}, year = {2004}, pages = {2317{\textendash}2329}, publisher = {Taylor \& Francis}, author = {Lu, D-C and De Graef, M and Pollock{\textdagger}, TM} } @article {biery2003method, title = {A method for measuring microstructural-scale strains using a scanning electron microscope: applications to $\gamma$-titanium aluminides}, journal = {Metallurgical and Materials Transactions A}, volume = {34}, number = {10}, year = {2003}, pages = {2301{\textendash}2313}, publisher = {Springer-Verlag}, author = {Biery, Nicholas and De Graef, Marc and Pollock, Tresa M} } @article {biery2002use, title = {Use of Weibull statistics to quantify property variability in TiAl alloys}, journal = {Metallurgical and Materials Transactions A}, volume = {33}, number = {10}, year = {2002}, pages = {3127{\textendash}3136}, publisher = {Springer}, author = {Biery, Nicholas and De Graef, Marc and Beuth, Jack and Raban, Rafel and Elliott, Andrew and Pollock, Tresa M and AUSTIN, CURT} } @article {li2001effect, title = {On the effect of low and high pressure hydrogen charging on the oxidation of a Ti{\textendash}48Al{\textendash}2Cr{\textendash}2Nb alloy}, journal = {Materials Science and Engineering: A}, volume = {318}, number = {1}, year = {2001}, pages = {224{\textendash}234}, publisher = {Elsevier}, author = {Li, K and Pollock, TM and De Graef, M and Habel, U and Thompson, AW} } @article {biery2001influence, title = {Influence of microstructure and strain distribution on failure properties in intermetallic TiAl-based alloys}, journal = {Materials Science and Engineering: A}, volume = {319}, year = {2001}, pages = {613{\textendash}617}, publisher = {Elsevier}, author = {Biery, NE and De Graef, M and Pollock, TM} } @article {biery1999displacement, title = {Displacement Mapping During In-Situ Straining In The SEM}, journal = {MICROSCOPY AND MICROANALYSIS-NEW YORK-}, volume = {5}, number = {2}, year = {1999}, pages = {334{\textendash}335}, publisher = {Springer Science and Media}, author = {Biery, NE and Pollock, TM and Nuhfer, NT and De Graef, M} } @article {dary1996effects, title = {Effects of environment on the tensile and creep behavior of a low-oxygen orthorhombic-based titanium aluminide, Ti-22 Al-23 Nb}, journal = {Titanium{\textquoteright}95- Science and technology}, year = {1996}, pages = {396{\textendash}403}, author = {Dary, Francois-Charles and Woodard, Shiela A and Pollock, Tresa M} } @article {dary1996effects, title = {Effects of high temperature air and vacuum exposures on the room temperature tensile behavior of the (O+ B2) titanium aluminide Ti-22Al-23Nb}, journal = {Materials Science and Engineering: A}, volume = {208}, number = {2}, year = {1996}, pages = {188{\textendash}202}, publisher = {Elsevier}, author = {Dary, Francois-Charles and Pollock, Tresa M} } @article {li1995new, title = {A new phase in hydrogen-charged Ti 48Al 2Cr 2Nb}, journal = {Scripta metallurgica et materialia}, volume = {32}, number = {7}, year = {1995}, pages = {1009{\textendash}1014}, publisher = {Pergamon}, author = {Li, K and Pollock, TM and Thompson, AW and De Graef, M} }