Atomistic simulations of the effect of a void on nanoindentation response of nickel

Three-dimensional molecular dynamics simulations have been performed to investigate the effect of a void on the nanoindentation of nickel thin film. The radius and depth of the void are varied to explore how they influence the nanoindentation. The simulation results reveal that the presence of a void softens the material and allows for a larger indentation depth at a given load compared to the no void case. The radius and depth of the void have a major effect on the indentation behaviors of the thin film. It is also observed that the void will collapse during the nanoindentation of crystal with void. And when the indentation depth is sufficiently large, the void will disappear. It is found that the indentation depth needed to make the void disappear depends on the void size and location.