Multiscale analysis of the effects of nanocavity on nanoindentation

Based on the EAM (embedded atom method), multiscale simulations are performed to study the effects of a nanocavity on nanoindentation of copper film with a hard frictionless indenter by employing the quasicontinuum method (QCM). The crystallographic orientation of the film in this study is [ 1 1 1 ] / [ 1 ¯ 1 0 ] and five different shapes of nanocavities, i.e. circle, ellipse, triangle, rectangle and rhombus are thoroughly studied by gradually changing the geometrical parameters of each kind of nanocavity. In addition, we compared the load–displacements curves for different shapes of nanocavity with different geometrical properties and their relative positions from the top surface of thin film. The strong effects of the geometry of the nanocavity as a kind of defects in the film during the nanoindentation are observed. It is found that both the elastic part of the response and the dislocation nucleation largely depend on the shape of the cavity and its geometrical parameters and location.