Effect of plasticity on nanoscale wear of third-body particles

Abstract

Understanding third-body wear is difficult when the size of the third-body particle reaches nanoscale, because the plasticity produced at the nanoscale exhibits a size effect resulting from the dislocation plasticity in a finite volume. Through molecular dynamics simulations, we observed that dislocation plasticity induces two failure patterns of the third-body wear: brittle failure due to highly localized deformation in mildly compressive particles and ductile failure due to exfoliation-like deformation in severely compressed particles. During the wear process, the deformation of third-body particle shows better ductility as the particle size increases. Due to the highest dislocation plasticity, the wear volume reaches the maximum at the critical compressive strain of ~13%. In addition, a size-independent wear rate is observed for the third-body wear.