Mesoscopic Analysis of Structure and Strength of Dislocation Junctions in FCC Metals

TL;DR

This paper introduces a finite element dislocation dynamics model for FCC metals that accurately reproduces dislocation junction structures and analyzes their strength through stress-strength diagrams.

Contribution

It presents a novel finite element model incorporating anisotropic elasticity and partial dislocation separation to simulate dislocation junctions in FCC metals.

Findings

Model reproduces Lomer-Cottrell lock structures accurately

The stress-strength diagram characterizes junction dissolution

Model aligns with atomistic simulation results

Abstract

We develop a finite element based dislocation dynamics model to simulate the structure and strength of dislocation junctions in FCC crystals. The model is based on anisotropic elasticity theory supplemented by the explicit inclusion of the separation of perfect dislocations into partial dislocations bounding a stacking fault. We demonstrate that the model reproduces in precise detail the structure of the Lomer-Cottrell lock already obtained from atomistic simulations. In light of this success, we also examine the strength of junctions culminating in a stress-strength diagram which is the locus of points in stress space corresponding to dissolution of the junction.