Annihilation of edge dislocation loops via climb during nanoindentation

Abstract

In this work, we explore the role of dislocation climb in annihilating the dislocation microstructure produced during a nanoindentation test. We produce creep conditions in Molecular Dynamics (MD) simulations of nanoindentation and show that half prismatic edge dislocation loops annihilate via pipe diffusion of vacancies from the free surface. Inspired by the MD simulations, we develop a model for the annihilation rate of these loops via pipe diffusion and compare it with the contribution of bulk diffusion. The model allows us discussing the temperatures at which we expect climb to prevail in experimental conditions and explain why climb is imperative during nanoindentation experiments.