The role of rough surface in the size-dependent behavior upon nano-indentation

The hardness measured by nano-indentation on metallic material with rough surface shows a significant deviation from the Nix-Gao relation, which established an important relation between the hardness and indentation depth at small scale (Nix and Gao, 1998). Such effect has been investigated by nano-indentation experiments, and accounted for in a few proposed nano-indentation models in terms of surface roughness. However, the predicted roughness...