Graphene coating makes copper more resistant to plastic deformation

Abstract

Nanoindentation tests and molecular dynamics (MD) simulations are conducted to investigate the effect of graphene (Gr) coating on the deformation behavior of a orientation copper (Cu) substrate. Distinct displacement burst (pop-in) is observed in the load-depth curve, which is due to the fracture of the Gr coating. Compared to bare Cu, the MD simulations indicate different dislocation activities at the Gr/Cu interface. The effect of image stress confinement on the glide of dislocations in Cu is considered to be the reason responsible for the increased hardness in the Gr/Cu system.