Deformation behaviors of a model metallic glass under 3-D nanoindentation studied in molecular dynamics simulation

Abstract

In recent years, molecular dynamics (MD) simulation has been used to study the deformation behaviors of glass under nanoindentation, mainly using ideal geometries like a spherical indenter or a 2.5-D sample geometry to simplify post-analysis and save computational costs. To generate stress/strain fields that can be directly compared with experiments, we developed a 3-D nanoindentation protocol in this work to study the deformation behaviors of a model metallic glass under sharp contact loading in MD. Our studies show that the indenter sharpness controls the shear band formation, and the interaction between shear bands dictates the crack initiation in the model metallic glass. Shear bands and residual stress fields in the model metallic glass from our simulated nanoindentation tests are consistent with observations in soda-lime silicate (SLS) glass from the instrumented indentation in experiments, as both of them favor shear deformation under sharp contact loading.