Crack initiation in an indented metallic glass with embedded nanoparticle

Nanoindentation was performed on a metallic glass with an embedded glassy nanoparticle using molecular dynamics simulations to investigate the effect of the second phase on shear band formation and crack initiation. It was found that the addition of a nanoparticle having a lower elastic modulus compared to that of matrix centralizes the region of shear strain below the indenter, which facilitates crack initiation. In contrast, the addition of a nanoparticle with a higher elastic modulus has the effect of branching the shear band, which confines the shear bands within the hydrostatic zone and suppresses crack initiation.