Dislocation nucleation during nanoindentation of aluminum

Through multiscale simulations, we explore the influence of both smooth and atomically rough indenter tips on the nucleation of dislocations during nanoindentation of single-crystal aluminum. We model the long-range strain with finite element analysis using anisotropic linear elasticity. We then model a region near the indenter atomistically and perform molecular dynamics with an embedded atom method interatomic potential. We find that smooth indenters nucleate dislocations below the surface but rough indenters can nucleate dislocations both at the surface and below. Increasing temperature from 0 to 300 K creates prenucleation defects in the region of high stress and decreases the critical depth. DOI: 10.1063/1.3021305