The vacancy - edge dislocation interaction in fcc metals: a comparison between atomic simulations and elasticity theory

TL;DR

This study compares atomic simulations and elasticity theory to analyze vacancy and edge dislocation interactions in fcc metals, identifying the limits of elasticity applicability and refining predictive models.

Contribution

It provides a detailed comparison between atomic and elasticity models for vacancy-dislocation interactions in fcc metals, establishing the minimal separation distance for elasticity validity.

Findings

Elasticity theory accurately predicts interactions at larger distances.

Atomic simulations provide detailed insights at small separation distances.

The study estimates the refinement needed for elasticity models to match atomic results.

Abstract

The interaction between vacancies and edge dislocations in face centered cubic metals (Al, Au, Cu, Ni) is studied at different length scales. Using empirical potentials and static relaxation, atomic simulations give us a precise description of this interaction, mostly in the case when the separation distance between both defects is small. At larger distances, elasticity theory can be used to predict this interaction. From the comparison between both approaches we obtain the minimal separation distance where elasticity applies and we estimate the degree of refinement required in the calculation. In this purpose, isotropic and anisotropic elasticity is used assuming a perfect or a dissociated edge dislocation and considering the size effect as well as the inhomogeneity interaction.