Predicting dislocation climb: Classical modeling versus atomistic simulations

TL;DR

This paper compares classical and atomistic models of dislocation climb in bcc iron, demonstrating that classical models can accurately predict climb velocities and validate creep models at experimentally relevant densities.

Contribution

It shows that classical continuum models can quantitatively match atomistic simulations for dislocation climb in bcc iron, extending their applicability to experimental conditions.

Findings

Classical model agrees with atomistic simulations in predicting climb velocities.

Extrapolation validates the pure climb creep model at lower dislocation densities.

Classical approach effectively describes dislocation climb phenomena.

Abstract

The classical modeling of dislocation climb based on a continuous description of vacancy diffusion is compared to recent atomistic simulations of dislocation climb in body-centered cubic iron under vacancy supersaturation [Phys. Rev. Lett. 105 095501 (2010)]. A quantitative agreement is obtained, showing the ability of the classical approach to describe dislocation climb. The analytical model is then used to extrapolate dislocation climb velocities to lower dislocation densities, in the range corresponding to experiments. This allows testing of the validity of the pure climb creep model proposed by Kabir et al. [Phys. Rev. Lett. 105 095501 (2010)].