Title: Elastic interactions between microstructural features and their influence on macroscopic mechanical behavior

Abstract: The microstructures of many engineering materials contain multiple phases with varying mechanical properties. The interactions between these phases give rise to the observed macroscopic behavior; however, the specific relationships between microstructural phenomena and macroscopic properties are often unclear. For example, during elastic loading of two-phase titanium alloys the lower stiffness β-phase imparts an interaction stress on the α-phase that modifies the local stress state, promoting or suppressing different deformation modes.  In this study we simulate the interaction of these phases using a 3-D microstructural finite element model with systematically varying interface and loading orientations. We demonstrate that the interaction stresses are responsible for up to 40% of the resolved shear stress near the α-β interface, with strong dependence on orientation. Further, comparison of our model results with experimental measurements reveals similar trends. Following presentation of these results, we discuss implications for mechanical behavior in critical applications and opportunities for integration into higher length scale engineering models.

Bio:  Will Joost is a Principal Materials Engineer at Pratt & Whitney in East Hartford, CT, where he focuses on applying computational materials science and integrated computational materials engineering (ICME) towards advances in jet engines. His primary area of research is multi-scale modeling of mechanical behavior and tribology in crystalline materials. Prior to joining Pratt, Will spent 7 years as the Program Manager for Lightweight Metals in the Vehicle Technologies Office at the U.S. Department of Energy where he oversaw a portfolio of R&D projects. Will also spent time as a postdoctoral researcher in the Theoretical Division at Los Alamos National Laboratory writing high performance computing code for dislocation dynamics simulations. Will holds a B.S. from RPI, an M.S. from Arizona State University, and a Ph.D. from the University of Maryland, all in Materials Science and Engineering.