Investigation of mechanical properties of gold nanocoating using nanoindentation experiments

Molecular dynamics simulation is used to determine the mechanical properties of gold coating from indentation. The results show that the depressed surface generation process should be attributed to three key factors: first, the atom inclined to go to its original crystal position under the molecular interactions; second, the attractive force exerted by the indenter at the unloading stage; third, the self-organization effect induced by surface/subsurface atoms, and the final depressed surface is generated through the strong nonlinear coupling effect of these three basic factors. There are little anisotropy phenomenon in the elastic deformation stage while obvious anisotropy phenomenon is observed in the plastic deformation process. The maximum value of contact pressure is located at the edge of contact area and vanished outward from the contact circle. The magnitudes of the maximum principal stresses appear to shift outward, away from the center of contact area.