Boundary Behaviour and Confinement of Screw Dislocations

TL;DR

This paper analyzes screw dislocation dynamics near boundaries and proposes boundary conditions that energetically favor their confinement inside materials, supported by analytical and numerical results.

Contribution

It provides new analytical estimates for dislocation-boundary collisions and demonstrates how specific boundary conditions can confine dislocations within a domain.

Findings

Analytical estimates for collision times with boundaries and between dislocations.

Numerical evidence supporting collision time estimates.

Boundary conditions that energetically favor dislocation confinement.

Abstract

In this note we discuss two aspects of screw dislocations dynamics: their behavior near the boundary and a way to confine them inside the material. In the former case, we obtain analytical results on the estimates of collision times (one dislocation with the boundary and two dislocations with opposite Burgers vectors with each other); numerical evidence is also provided. In the latter, we obtain analytical results stating that, under imposing a certain type of boundary conditions, it is energetically favorable for dislocations to remain confined inside the domain.