Molecular Dynamics Simulation of Plastic Deformation in Cu Nanowires under Cyclic Loading: Effect of Crystal Orientation

Abstract

In this study, we carried out molecular dynamics simulations of fatigue of single-crystal copper nanowires for the purpose of revealing the fatigue mechanisms of metal nanowires. We examined four nanowire models with different crystal orientations to investigate the effect of the single- and multi-slip deformation. Cyclic tension and compression were applied to the nanowire models. As a result, we observed that atomic vacancies were formed by dislocation motion during cyclic deformation. We found two types of the vacancy formation mechanisms, i.e., motion of a jogged screw dislocation and intersection of two stacking faults in different slip systems, which are the possible causes of fatigue in nanomaterials.