@article {2196, title = {Navigating the BCC-B2 refractory alloy space: Stability and thermal processing with Ru-B2 precipitates}, journal = {Acta Materialia}, volume = {265}, year = {2024}, pages = {119628}, abstract = {

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

}, keywords = {B2 phase, Calphad, Combinatorial, High temperature materials, Precipitation strengthening, Refractory multi principal element alloys, Thermal processing}, issn = {1359-6454}, doi = {https://doi.org/10.1016/j.actamat.2023.119628}, url = {https://www.sciencedirect.com/science/article/pii/S1359645423009564}, author = {Sebastian A. Kube and Carolina Frey and Chiyo McMullin and Ben Neuman and Kaitlyn M. Mullin and Tresa M. Pollock} } @article {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 {1941, title = {Nucleation of recrystallization in magnesium alloy grains of varied orientation and the impacts on texture evolution}, journal = {Journal of Magnesium and Alloys}, volume = {10}, year = {2022}, month = {10}, doi = {10.1016/j.jma.2022.09.006}, author = {Miller, Victoria and Nie, J.F. and Pollock, Tresa} } @article {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 {1331, title = {A new proximate structure for the APB (111) in L12 compounds}, journal = {Scripta Materialia}, volume = {182}, year = {2020}, pages = {38{\textendash}42}, abstract = {

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

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

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

}, keywords = {3d materials, contrast tomography, diffraction, grain growth, microstructure evolution, nondestructive x-ray diffraction contrast, science, strontium titanate, to, tomography imaging was used}, doi = {10.1107/S160057672000093X}, author = {Trenkle, Andreas and Syha, Melanie and Rheinheimer, Wolfgang and Callahan, Patrick and Nhuyen, Lily and Ludwig, Wolfgang and Lenthe, William and Echlin, Mclean and Pollock, Tresa and Weygand, Daniel and Hoffmann, Michael and Gumbsch, Peter} } @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 {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 {echlin2012new, title = {A new TriBeam system for three-dimensional multimodal materials analysis}, journal = {Review of Scientific Instruments}, volume = {83}, number = {2}, year = {2012}, pages = {023701}, publisher = {AIP Publishing}, author = {Echlin, McLean P and Mottura, Alessandro and Torbet, Christopher J and Pollock, Tresa M} } @article {echlin2011new, title = {A New Femtosecond Laser-Based Tomography Technique for Multiphase Materials}, journal = {Advanced Materials}, volume = {23}, number = {20}, year = {2011}, pages = {2339{\textendash}2342}, publisher = {Wiley Online Library}, author = {Echlin, McLean P and Husseini, Naji S and Nees, John A and Pollock, Tresa M} } @article {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 {kumar2009nonlinear, title = {Nonlinear ultrasonics for in situ damage detection during high frequency fatigue}, journal = {Journal of Applied Physics}, volume = {106}, number = {2}, year = {2009}, pages = {024904}, publisher = {AIP Publishing}, author = {Kumar, Anish and Torbet, Christopher J and Jones, J Wayne and Pollock, Tresa M} } @article {pollock2006nickel, title = {Nickel-based superalloys for advanced turbine engines: chemistry, microstructure and properties}, journal = {Journal of propulsion and power}, volume = {22}, number = {2}, year = {2006}, pages = {361{\textendash}374}, author = {Pollock, Tresa M and Tin, Sammy} } @conference {feng2005new, title = {New phases in a multicomponent high ruthenium single crystal superalloy}, booktitle = {Materials Science Forum}, volume = {475}, year = {2005}, pages = {655{\textendash}660}, publisher = {Trans Tech Publications}, organization = {Trans Tech Publications}, author = {Feng, Q and Rowland, LJ and Pollock, TM} } @conference {feng2004new, title = {New Phases in Ruthenium-Containing Single-Crystal Superalloys}, booktitle = {Superalloys 2004: The Tenth International Symposium on Superalloys}, year = {2004}, pages = {769{\textendash}778}, author = {Feng, Q and Nandy, TK and Rowland, LJ and Tryon, B and Banerjee, D and Pollock, TM} } @booklet {king2000nickel, title = {Nickel-based superalloys exhibiting minimal grain defects}, year = {2000}, note = {US Patent 6,096,141}, author = {King, Warren Tan and Pollock, Tresa M and Zemsky, Christine Louise and Murphy, Wendy Howard} } @article {kolluru1998numerical, title = {Numerical modeling of the creep behavior of unidirectional eutectic composites}, journal = {Acta materialia}, volume = {46}, number = {8}, year = {1998}, pages = {2859{\textendash}2876}, publisher = {Elsevier}, author = {Kolluru, Dakshinamurthy V and Pollock, Tresa M} } @article {li1995new, title = {A new phase in hydrogen-charged Ti 48Al 2Cr 2Nb}, journal = {Scripta metallurgica et materialia}, volume = {32}, number = {7}, year = {1995}, pages = {1009{\textendash}1014}, publisher = {Pergamon}, author = {Li, K and Pollock, TM and Thompson, AW and De Graef, M} } @booklet {walston1995nickel, title = {Nickel-base superalloy and article with high temperature strength and improved stability}, year = {1995}, note = {US Patent 5,455,120}, author = {Walston, William S and Ross, Earl W and Pollock, Tresa M and O{\textquoteright}hara, Kevin S and Murphy, Wendy H} }