The Mechanistic Origins of Strengthening and Stability in Nanostructured Materials: A Computationally-Guided Approach

Abstract

Engineering interest in nanostructuered materials has been founded on the potential to improve a myriad of mechanical properties such as increased strength/hardness, while scientific interest stems from the alternative fundamental mechanisms that are operative. Compared to their coarser-grained counterparts, the influence of interfaces (i.e., grain boundaries) becomes more significant in nanostructured materials. Current simulation techniques for understanding the mechanics in nanocrystalline alloys rely on non-physical microstructures, first-order grain boundary descriptors that poorly capture the complexity of interfacial structure-property relationships, and a lack of quantitative approaches that can accurately capture the specific contribution of different deformation mechanisms. In this study, we propose utilizing higher-order descriptors to improve our understanding of interfacial-driven strengthening and stability. These descriptors then aid in our boundary network modeling to understand larger-scale polycrystalline behavior by unraveling the complexity surrounding the competition/cooperation between different deformation mechanisms, as a function of grain size. The contribution of interfaces and dislocation-mediated deformation to the total strain in the material is resolved via continuum-based kinematic metrics, while the importance of choosing physically-based atomistic microstructures and proper equilibration techniques is shown. By unraveling the mechanistic origins of strengthening and stability in nanostructured materials, we demonstrate how such a fundamental understanding might be leveraged for future inverse materials design strategies.

Biography

Professor Tucker joined the Mechanical Engineering Department at Mines in the summer of 2017 as an Assistant Professor and is active in the interdisciplinary Materials Science program. Before joining the faculty at Mines, he spent 4 years as an Assistant Professor in the Department of Materials Science and Engineering at Drexel University (Philadelphia, PA), and 2 years as a Postdoctoral Research Appointee at Sandia National Laboratories (Albuquerque, NM) in the Computational Materials and Data Science group. While at Drexel, he was awarded the Outstanding Teacher Award in 2015 and the TMS Young Leader Professional Development Award in 2016. Professor Tucker earned his Ph.D. in 2011 from the Georgia Institute of Technology (School of Materials Science and Engineering), and a B.S. in 2004 from Westminster College (Salt Lake City, UT) majoring in both Physics and Mathematics. His research ambitions are aimed at integrating high-performance computing, materials theory, and novel computational tools to discover the fundamental structure-property relationships of emerging materials that will enable the predictive design of advanced materials with tunable properties.

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