Statistics of grain microstructure evolution under anisotropic grain boundary energies and mobilities using threshold-dynamics

Abstract

This paper investigates the statistical behavior of a two-dimensional grain microstructure during grain growth under anisotropic grain boundary characters. We employ the threshold- dynamics method, which allows for unparalleled computational speed, to simulate the full- field curvature motion of grain boundaries in a large polycrystal ensemble. Two sets of numerical experiments are performed to explore the effect of grain boundary anisotropy on the evolution of microstructure features. In the first experiment, we focus on abnormal grain growth and find that grain boundary anisotropy introduces a statistical preference for certain grain orientations. This leads to changes in the overall grain size distribution from the isotropic case. In the second experiment, we examine the texture development and growth of twin grain boundaries at different initial microstructures. We find that both phenomena are more pronounced when the initial microstructure has a dominant fraction of high-angle grain boundaries. Our results suggest effective grain boundary engineering strategies for improving material properties.