SUBJECT: Ph.D. Proposal Presentation
BY: Gashaw Bizana
TIME: Tuesday, May 16, 2023, 9:00 a.m.
PLACE: Georgia Tech Europe conference room and Zoom, N/A
TITLE: Grain boundary migration mechanisms in FCC metals under mechanical and capillary driving forces
COMMITTEE: Dr. Luis Barrales-Mora, Chair (ME)
Dr. Surya Kalidindi (ME)
Dr. Ting Zhu (ME)
Dr. Stephane Berbenni (CNRS-UL)
Dr. Joshua Kacher (MSE)


The physical and mechanical properties of polycrystalline metals are significantly influenced by the average grain size and crystallographic texture. Changes in these characteristics occur during grain growth and recrystallization, which are processes mediated by the migration of grain boundaries. Recent studies of bicrystals have shown that the motion normal to grain boundaries can be accommodated by the tangential translation of grains and/or shear deformation of the lattice traversed by the grain boundary. However, the exact conditions at which these mechanisms are activated are not yet well understood, especially in polycrystals. It has been hypothesized that the driving forces behind the migration may play a role. In this thesis, atomistic simulations are used to investigate the
mechanism of curvature and stress-driven grain boundary migration in both bicrystalline and polycrystalline FCC metals. Furthermore, the associated grain growth kinetics in the ploycrystal is thoroughly studied. To this aim, novel analytical tools are developed to enable a detailed analysis of microstructure development in polycrystals using data generated from atomistic simulations. The findings of this study are expected to provide insights into the effects of
high-temperature annealing and stress on microstructure evolution and facilitate the development of accurate microstructure-based models for grain growth in polycrystals, which is crucial for designing advanced materials for various engineering applications