@article {1961, title = {Determination of peak ordering in the CrCoNi medium-entropy alloy via nanoindentation}, journal = {Acta Materialia}, volume = {241}, year = {2022}, month = {09}, pages = {118380}, doi = {10.1016/j.actamat.2022.118380}, author = {Zhang, Mingwei and Yu, Qin and Frey, Carolina and Walsh, Flynn and Payne, Madelyn and Kumar, Punit and Liu, Dongye and Pollock, Tresa and Asta, Mark and Ritchie, Robert and Minor, Andrew} } @conference {1611, title = {Creep, Fatigue, and Oxidation Interactions During High and Very High Cycle Fatigue at Elevated Temperature of Nickel-Based Single Crystal Superalloys}, booktitle = {Superalloys 2020}, year = {2020}, abstract = {

High-temperature fatigue of Ni-based single crystal superalloys is studied at 1000 \°C in a wide range of loading conditions (\−1 ? R ? 0.8) and number of cycles (103 \− 109). Under fully reversed conditions, a competition between crack initiations from the surface\— assisted by oxidation\—and from internal metallurgical defects\—mostly large casting pores\—is observed. Increasing the testing frequency shifts the competition to a higher number of cycles. Conversely, decreasing the casting pore size or coating the specimen promotes surface initiations. When a positive mean stress is added (R ? 0), a creep deformation/damage mechanism mainly controls fatigue life, despite fracture surfaces presenting a variety of initiation types. Fatigue life can be predicted by a simple creep law if the contribution of the alternating stress is considered. A linear damage summation method that considers pure fatigue and pure creep damage is used to predict the fatigue lives, and Haigh diagrams for different alloys are presented.

}, keywords = {Creep, fatigue, High temperature, Superalloy}, isbn = {9783030518349}, doi = {10.1007/978-3-030-51834-9}, url = {http://dx.doi.org/10.1007/978-3-030-51834-9_65}, author = {Cervellon, A. and Yi, J. Z. and Corpace, F. and Hervier, Z. and Rigney, J. and Wright, P. K. and Torbet, C. J. and Cormier, J. and Jones, J. W. and Pollock, T. M.}, editor = {Tin, Sammy and Hardy, Mark and Clews, Justin and Cormier, Jonathan and Feng, Qiang and Marcin, John and O{\textquoteright}Brien, Chris and Suzuki, Akane} } @article {1696, title = {Grain refinement mechanisms in additively manufactured nano-functionalized aluminum}, journal = {Acta Materialia}, volume = {200}, year = {2020}, pages = {1022{\textendash}1037}, abstract = {

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

}, keywords = {Additive manufacturing, Crystallography, Grain refinement, Nucleation, Solidification}, issn = {13596454}, doi = {10.1016/j.actamat.2020.09.043}, url = {https://doi.org/10.1016/j.actamat.2020.09.043}, author = {Martin, J. Hunter and Yahata, Brennan and Mayer, Justin and Mone, Robert and Stonkevitch, Ekaterina and Miller, Julie and O{\textquoteright}Masta, Mark R. and Schaedler, Tobias and Hundley, Jacob and Callahan, Patrick and Pollock, Tresa} } @article {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 {1356, title = {Dislocation dynamics in a nickel-based superalloy via in-situ transmission scanning electron microscopy}, journal = {Acta Materialia}, volume = {168}, year = {2019}, pages = {152{\textendash}166}, abstract = {

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

}, keywords = {Dislocations dynamic, In-situ transmission scanning electron microscopy (TSEM), Nickel-based superalloy ren{\'e} 88DT, Plastic localization, STEM detector, Twin boundary}, issn = {13596454}, doi = {10.1016/j.actamat.2018.12.061}, url = {https://doi.org/10.1016/j.actamat.2018.12.061}, author = {Stinville, J. C. and Yao, Eric R. and Callahan, Patrick G. and Shin, Jungho and Wang, Fulin and Echlin, Mclean P. and Pollock, Tresa M. and Gianola, Daniel S.} } @article {1176, title = {Transmission Scanning Electron Microscopy: Defect Observations and Image Simulations}, journal = {Ultramicroscopy }, volume = {186}, year = {2018}, chapter = {49}, doi = {https://doi.org/10.1016/j.ultramic.2017.11.004}, author = {Callahan, PG and Stinville, JC and Yao, ER and Echlin, MP and Titus, MS and De Graef, M and Pollock, TM and Gianola, DS} } @article {1211, title = {3D printing of high-strength aluminium alloys}, journal = {Nature}, volume = {549}, year = {2017}, pages = {365{\textendash}369}, doi = {10.1038/nature23894}, author = {Martin, John H. and Yahata, Brennan D. and Hundley, Jacob M. and Mayer, Justin A. and Schaedler, Tobias A. and Pollock, Tresa M.} } @article {miller2014simulation, title = {Simulation of diffusion-limited lateral growth of dendrites during solidification via liquid metal cooling}, journal = {Acta Materialia}, volume = {69}, year = {2014}, pages = {47{\textendash}59}, publisher = {Pergamon}, author = {Miller, JD and Yuan, L and Lee, PD and Pollock, TM} } @article {torralva2011critical, title = {The Critical Role of Shock Melting in Ultrafast Laser Machining}, journal = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 United States.[np]. Feb}, year = {2011}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 United States}, author = {Torralva, Ben and Ma, S and Kumar, A and Yalisove, SM and Pollock, TM and Thornton, K} } @article {miller2011heat, title = {Heat Extraction and Structure Evolution in LMC Single-Crystal Growth}, journal = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 United States.[np]. Feb}, year = {2011}, publisher = {Minerals, Metals and Materials Society/AIME, 420 Commonwealth Dr., P. O. Box 430 Warrendale PA 15086 United States}, author = {Miller, Jonathan and Yuan, Lang and Eisman, Michael and Lee, Peter and Pollock, Tresa} } @article {mcdonald2008approaching, title = {Approaching non-destructive surface chemical analysis of CMSX-4 superalloy with double-pulsed laser induced breakdown spectroscopy}, journal = {Spectrochimica Acta Part B: Atomic Spectroscopy}, volume = {63}, number = {5}, year = {2008}, pages = {561{\textendash}565}, publisher = {Elsevier}, author = {McDonald, Joel P and Das, Dipak K and Nees, John A and Pollock, Tresa M and Yalisove, Steven M} } @article {das2008depth, title = {Depth-profiling study of a thermal barrier coated superalloy using femtosecond laser-induced breakdown spectroscopy}, journal = {Spectrochimica Acta Part B: Atomic Spectroscopy}, volume = {63}, number = {1}, year = {2008}, pages = {27{\textendash}36}, publisher = {Elsevier}, author = {Das, DK and McDonald, JP and Yalisove, SM and Pollock, TM} } @article {das2008detection, title = {Detection of a marker layer in a 7YSZ thermal barrier coating by femtosecond laser-induced breakdown spectroscopy}, journal = {Surface and Coatings Technology}, volume = {202}, number = {16}, year = {2008}, pages = {3940{\textendash}3946}, publisher = {Elsevier}, author = {Das, Dipak K and McDonald, Joel P and Levi, Carlos G and Yalisove, Steve M and Pollock, Tresa M} } @article {mcdonald2008femtosecond, title = {Femtosecond pulsed laser ablation dynamics and ablation morphology of nickel based superalloy CMSX-4}, journal = {Journal of Applied Physics}, volume = {103}, number = {9}, year = {2008}, pages = {093111}, publisher = {AIP Publishing}, author = {McDonald, Joel P and Ma, Shuwei and Pollock, Tresa M and Yalisove, Steven M and Nees, John A} } @article {das2008femtosecond, title = {Femtosecond pulsed laser damage characteristics of 7\% Y2O3-ZrO2 thermal barrier coating}, journal = {Applied Physics A}, volume = {91}, number = {3}, year = {2008}, pages = {421{\textendash}428}, publisher = {Springer}, author = {Das, DK and McDonald, JP and Yalisove, SM and Pollock, TM} } @conference {mcdonald2007dynamics, title = {Dynamics of Ultrafast Laser Induced Damage in Single Crystal Ni-Based Superalloy During Machining}, booktitle = {Advanced Intermetallic-Based Alloys(MRS Symposium Proceedings Series Volume 980)}, volume = {980}, year = {2007}, pages = {571{\textendash}576}, author = {McDonald, Joel P and Ma, Shuwei and Nees, John A and Pollock, Tresa M and Yalisove, Steven M} } @article {ma2007femtosecond, title = {Femtosecond laser ablation regimes in a single-crystal superalloy}, journal = {Metallurgical and Materials Transactions A}, volume = {38}, number = {13}, year = {2007}, pages = {2349{\textendash}2357}, publisher = {Springer}, author = {Ma, S and McDonald, JP and Tryon, B and Yalisove, SM and Pollock, TM} } @article {tryon2007hybrid, title = {Hybrid intermetallic Ru/Pt-modified bond coatings for thermal barrier systems}, journal = {Surface and Coatings Technology}, volume = {202}, number = {2}, year = {2007}, pages = {349{\textendash}361}, publisher = {Elsevier}, author = {Tryon, B and Murphy, KS and Yang, JY and Levi, CG and Pollock, TM} } @article {yi2007ultrasonic, title = {Ultrasonic fatigue of a single crystal Ni-base superalloy at 1000 C}, journal = {Materials Science and Engineering: A}, volume = {443}, number = {1}, year = {2007}, pages = {142{\textendash}149}, publisher = {Elsevier}, author = {Yi, JZ and Torbet, CJ and Feng, Q and Pollock, TM and Jones, JW} } @conference {mcdonald2006dynamics, title = {Dynamics of Ultrafast Laser Induced Damage in Single Crystal Ni-Based Superalloy During Machining}, booktitle = {MRS Proceedings}, volume = {980}, year = {2006}, pages = {0980{\textendash}II05}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, author = {McDonald, Joel P and Ma, Shuwei and Nees, John A and Pollock, Tresa M and Yalisove, Steven M} } @article {feng2006femtosecond, title = {Femtosecond laser machining of single-crystal superalloys through thermal barrier coatings}, journal = {Materials Science and Engineering: A}, volume = {430}, number = {1}, year = {2006}, pages = {203{\textendash}207}, publisher = {Elsevier}, author = {Feng, Q and Picard, YN and McDonald, JP and Van Rompay, PA and Yalisove, SM and Pollock, TM} } @article {tryon2006multilayered, title = {Multilayered ruthenium-modified bond coats for thermal barrier coatings}, journal = {Metallurgical and Materials Transactions A}, volume = {37}, number = {11}, year = {2006}, pages = {3347{\textendash}3358}, publisher = {Springer}, author = {Tryon, B and Feng, Q and Pollock, TM and Wellman, RG and Nicholls, JR and Murphy, KS and Yang, J and Levi, CG} } @article {das2006qualitative, title = {Qualitative Characterization of a Thermal Barrier Coating System Using Femtosecond Laser-Induced Breakdown Spectroscopy}, journal = {MATERIALS SCIENCE AND TECHNOLOGY-ASSOCIATION FOR IRON AND STEEL TECHNOLOGY-}, volume = {5}, year = {2006}, pages = {621}, publisher = {ASSOCIATION FO IRON AND STEEL INDUSTRY}, author = {Das, DK and McDonald, JP and Yalisove, SM and Pollock, TM} } @article {feng2005femtosecond, title = {Femtosecond laser micromachining of a single-crystal superalloy}, journal = {Scripta materialia}, volume = {53}, number = {5}, year = {2005}, pages = {511{\textendash}516}, publisher = {Elsevier}, author = {Feng, Q and Picard, YN and Liu, H and Yalisove, SM and Mourou, G and Pollock, TM} }