A 3D phase field dislocation dynamics model for body-centered cubic crystals

TL;DR

This paper introduces a 3D phase field dislocation dynamics model tailored for BCC metals, capturing dislocation behaviors and comparing favorably with molecular statics simulations, advancing understanding of dislocation mechanics.

Contribution

The paper develops an extended 3D PFDD model that incorporates line-character dependence of the Peierls barrier for BCC metals, enabling more accurate dislocation simulations.

Findings

The model accurately predicts dislocation loop expansion features.

It successfully simulates kink-pair motion of screw dislocations.

The model aligns well with molecular statics simulation results.

Abstract

In this work, we present a 3D Phase Field Dislocation Dynamics (PFDD) model for body-centered cubic (BCC) metals. The model formulation is extended to account for the dependence of the Peierls barrier on the line-character of the dislocation. Simulations of the expansion of a dislocation loop belonging to the $\left\{110\right\} \left<111\right>$ slip system are presented with direct comparison to Molecular Statics (MS) simulations. The extended PFDD model is able to capture the salient features of dislocation loop expansion predicted by MS simulations. The model is also applied to simulate the motion of a straight screw dislocation through kink-pair motion.