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

TL;DR

This study uses a fast threshold-dynamics simulation method to analyze how anisotropic grain boundary energies and mobilities influence microstructure evolution, revealing orientation preferences and texture development in polycrystals.

Contribution

It introduces a computationally efficient threshold-dynamics approach to study anisotropic grain boundary effects on microstructure evolution, including abnormal growth and texture formation.

Findings

Anisotropy causes a statistical preference for certain grain orientations.

Grain size distribution shifts due to boundary anisotropy.

Pronounced texture development with high-angle boundaries.

Abstract

This paper investigates the statistical behavior of two-dimensional grain microstructures 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.