An Atomistic View of Interface-Mediated Dislocation Plasticity in Thin Metal Films

Abstract

ABSTRACTAtomistic simulations using molecular statics are carried out to study dislocation plasticity in thin metal films attached to stiff substrates. The analysis utilizes a sample two-dimensional crystal, with an embedded initial point defect used for triggering dislocation activities in a controlled manner. The existence of an interface between the film and the substrate is shown to delay plastic yielding and lead to film strengthening. The capability of atoms to slide along the interface plays a crucial role in determining the macroscopic stress-strain response and the microscopic dislocation activities. Within the modeling framework we examine the quantitative interfacial sliding behavior and the resulting dislocation-interface interactions and their consequences.