An atomic-level model for studying the dynamics of edge dislocations in metals

Abstract

A model for simulating the dynamic behaviour of edge dislocations in metals at the atomic level is presented. The model extends an earlier approach based on an array of edge dislocations periodic in the Burgers vector direction and allows the external action (either shear strain or resolved shear stress), crystal energy, plastic displacement and dislocation position and velocity to be determined unambiguously. Two versions of the model for either static or dynamic conditions, i.e. zero or non-zero temperature, are described. The model is tested for elastic response of a perfect crystal and the atomic properties of a ½111 edge dislocation in a model of bcc Fe. Several examples of dislocation glide behaviour and dislocation–obstacle interactions at zero and non-zero temperature are presented and discussed.