Disconnection-Mediated Migration of Interfaces in Microstructures: II. diffuse interface simulations

TL;DR

This paper introduces a diffuse interface phase-field model for simulating microstructure evolution, capturing microscopic interface migration mechanisms and their effects on microstructure dynamics, including stress coupling effects.

Contribution

It extends the disconnection-mediated interface migration model to a diffuse interface framework suitable for large-scale simulations.

Findings

The method accurately captures microscopic interface migration effects.

Stress coupling significantly influences microstructure evolution.

Differences from classical mean curvature flow are demonstrated.

Abstract

The motion of interfaces is an essential feature of microstructure evolution in crystalline materials. While atomic-scale descriptions provide mechanistic clarity, continuum descriptions are important for understanding microstructural evolution and upon which microscopic features it depends. We develop a microstructure evolution simulation approach that is linked to the underlying microscopic mechanisms of interface migration. We extend the continuum approach describing the disconnection-mediated motion of interfaces introduced in Part I [Han, Srolovitz and Salvalaglio, 2021] to a diffuse interface, phase-field model suitable for large-scale microstructure evolution. A broad range of numerical simulations showcases the capability of the method and the influence of microscopic interface migration mechanisms on microstructure evolution. These include, in particular, the effects of stress and its coupling to interface migration which arises from disconnections, showing how this leads to important differences from classical microstructure evolution represented by mean curvature flow.