Atomistic Simulation of Flow Stress and Dislocation-Interface Interaction in Thin Metal Films

Abstract

AbstractThis study focuses on the atomistics of interface-mediated plasticity in thin metallic films. Molecular statics simulations are carried out to model the tensile stress-strain response of the free-standing and substrate-bonded films. In the free-standing film dislocation glide readily occurs, inducing slip steps at both surfaces of the film. The existence of an interface with the substrate constrains the dislocation motion in the film and restricts the slip steps to only the free surface. The propensity of film plasticity is dictated by the capability of atoms to slide along the interface. The flow stress of the film can be correlated with the dislocation activities obtained from the simulation. The propensity of spreading of relatively energetic atoms associated with the dislocation near the interface is also discussed.