Disconnection-Mediated Migration of Interfaces in Microstructures: I. continuum model

TL;DR

This paper introduces a continuum model for interface migration in microstructures that incorporates crystallography and disconnection mechanisms, providing a rigorous equation of motion for curved interfaces influenced by various driving forces.

Contribution

It develops a new interface migration model that accounts for crystallography and microscopic disconnection mechanisms, advancing the understanding of microstructure evolution.

Findings

Derived a comprehensive equation of motion for interface migration.

Validated the model with diffuse interface simulations for complex microstructures.

Established a framework linking microscopic mechanisms to macroscopic interface dynamics.

Abstract

A long-standing goal of materials science is to understand, predict and control the evolution of microstructures in crystalline materials. Most microstructure evolution is controlled by interface motion; hence, the establishment of rigorous interface equations of motion is a universal goal of materials science. We present a new model for the motion of arbitrarily curved interfaces that respects the underlying crystallography of the two phases/domains meeting at the interface and is consistent with microscopic mechanisms of interface motion; i.e., disconnection migration (line defects in the interface with step and dislocation character). We derive the equation of motion for interface migration under the influence of a wide range of driving forces. In Part II of this paper [Salvalaglio, Han and Srolovitz, 2021], we implement the interface model and the equation of motion proposed in this paper in a diffuse interface simulation approach for complex morphology and microstructure evolution.