Determination of activation parameters for dislocation formation from a surface in fcc metals by atomistic simulations

Abstract

Defects in free surfaces are expected to be seeds for the nucleation of dislocations, which is the likely way nanoscale materials suffer plastic deformation. The nucleation results in the competition between the image force attracting the dislocation to the surface and the applied strain. In this work, two methods based on molecular dynamics simulations using an embedded atom method (EAM) potential are used to determine the activation energy and the critical radius for the formation of dislocations from a surface defect in a typical fcc metal.