A phase field model for the motion of prismatic dislocation loops by both climb and self-climb

TL;DR

This paper develops a phase field model to simulate the motion of prismatic dislocation loops considering both climb and self-climb mechanisms, analyzing its mathematical properties and validating through numerical simulations.

Contribution

It introduces a novel phase field model incorporating nonlocal climb force and degenerate mobility, with proven well-posedness and numerical validation.

Findings

The model accurately captures dislocation loop evolution.

Numerical results show significant differences with and without self-climb.

The model's stability and existence of solutions are established.

Abstract

We study the sharp interface limit and well-posedness of a phase field model for self-climb of prismatic dislocation loops in periodic settings. The model is set up in a Cahn-Hilliard/Allen-Cahn framework featured with degenerate phase-dependent diffusion mobility with an additional stablizing function. Moreover, a nonlocal climb force is added to the chemical potential. We introduce a notion of weak solutions for the nonlinear model. The existence result is obtained by approximations of the proposed model with nondegenerate mobilities. Lastly, the numerical simulations are performed to validate the phase field model and the simulation results show the big difference for the prismatic dislocation loops in the evolution time and the pattern with and without self-climb contribution.