Topic: Grain Boundary Dynamics - Deformation Coupling

Speaker: Prof. David J. Srolovitz
         Chair Professor, Materials Science & Eng., City University of HongKong

Time: 10:30-12:00, (Wednesday) Sep. 5^th, 2018

Venue: Room 468，Lee Hsun Building, IMR CAS

Abstract:

It is well known that microstructure affects the mechanical response of materials (e.g., grain size strengthening and superplastisticity). Less well known is how mechanical loads can drive microstructure evolution and how microstructure evolution affects mechanical deformation. In this presentation, I discuss a new, quantitative approach to the linkage between mechanical loads and the evolution of polycrystalline microstructures. This approach is based up on a discrete, defect-level understanding of how interfaces move. I will first develop a discrete defect (disconnection) model and then apply it to stress-driven grain boundary (GB) migration, GB roughening and GB sliding. Based on this understanding, I will present a quantitative, continuum GB equation of motion based upon GB kinematics.  Finally, I’ll show applications of this model to polycrystals - including grain rotation, dislocation generation, growth stagnation. This is a topic that is evolving rapidly right now and represents unique opportunities to develop quantitative dislocation dynamics and crystal plasticity models for polycrystalline materials.

Brief Biography

David Srolovitz is the author of ~500 papers on topics in materials theory and simulations ranging from defects (surfaces, grain boundaries, dislocations, point defects), microstructure evolution (grain growth, dislocations, stress effects, phase transformations), deformation (nanomaterials, dislocation motion, creep), and film growth (sputtering, evaporation, CVD) and has an h-index of 87 with more than 29,000 literature citations. He is a Member of the National Academy of Engineering, Fellow of MRS, TMS, ASM, Institute of Physics and is the winner of the 2013 MRS Materials Theory Award. Srolovitz did his undergraduate work in Physics at Rutgers University and PhD from the University of Pennsylvania. He was a staff member at Exxon Corporate Research and Los Alamos National Laboratory early in his career and then was professor at the University of Michigan(Materials Science and Applied Physics), Princeton University (Mechanical and Aerospace Engineering, Applied Mathematics), and the University of Pennsylvania (Materials Science & Eng. and Mechanical Engineering & Applied Mechanics). He is currently a Chair Professor at the City University of HongKong (Materials Science & Eng.) and a Senior Fellow of the Institute for Advanced Study and the Joseph Bordogna Professor of Engineering and Applied Science (and Director of the Penn Institute for Computational Science) at the University of Pennsylvania. He also served as the Executive Director of the Institute of High Performance Computing and the Scientific Director of the Science and Engineering Research Council in Singapore.