Influence of surface roughening on indentation behavior of thin copper coatings using a molecular dynamics approach

The structure of interest consists of a nanometer thin copper coating, resting on an infinitely stiff substrate and subjected to nanoindentation by a rigid diamond indenter. The elastic and plastic properties of the coating are investigated for different surface roughening position of attack by the indenter using molecular dynamics. The force-displacement curves, the lattice disorders and the stresses are monitored during indentation to determine the onset of plasticity, plasticity development and stiffness in the different cases. It was found that both the surface roughening and point of attack of the indenter strongly affect the elastic and plastic behavior of the thin coating.