Atomistic perspective of how graphene protects metal substrate from surface damage in rough contacts

In recent years, many attempts have been made to explore the protective capability of graphene as an anti-wear coating for nanotribology. By the molecular dynamics simulations of the nanoindentation of a graphene/Fe (110) system, we provide a new insight into the atomistic mechanism of how graphene protects a metal substrate during a rough contacting process. We demonstrate that, in rough contacts, graphene can increase the loading area and homogenize the contact stress. It can weaken the effect of the surface roughness, reduce the magnitude of the contact stress and change its distribution. Finally, graphene can inhibit the nucleation of the surface dislocation and improve the load bearing capacity. These findings demonstrate that graphene holds great promise as effective protective coatings for contact damage.