Atomistic Study of Tip Radius Effect of Nanoindentation on Nanocrystalline Cu

Abstract

In current study we investigate deformation mechanisms of nanocrystalline Cu subjected to nanoindentation using atomistic simulation. Our results show that in addition to dislocation activities, grain boundaries associated mechanisms and deformation twinning are also observed during deformation process. Subsequent evaluation of indentation tip radius effects shows the maximum load for elastic-plastic deformation transition increases with increasing tip radius. There is a critical tip radius for mediating deformation mechanisms: below which dislocation density increase with increasing tip radius, while above which grain boundary associated mechanisms is more pronounced.