Molecular dynamics simulation of frictional strengthening behavior of graphene on stainless steel substrate

Abstract

During the last few years, friction studies of graphene applied to stainless-steel materials have mainly focused on the macroscopic scale, but the friction behavior and friction mechanism of graphene on stainless-steel surfaces at the nanoscale are still unclear. Here, the frictional behavior of graphene on stainless-steel was analyzed by molecular dynamics simulations. The results show that the average adsorption energy between stainless-steel and graphene is large, but the graphene/stainless-steel system exhibits frictional strengthening behavior. The frictional strengthening behavior decreases with the increase of the number of graphene layers. In addition, the frictional strengthening behavior appears only in localized regions of graphene on the stainless-steel surface. We demonstrate that the polycrystalline character of stainless-steel is a key factor in the appearance of frictional strengthening behavior. The presence of stainless-steel grain boundaries causes the change of graphene adsorption state, which leads to the appearance of graphene friction forcing behavior. Moreover, the multi-element characteristics of stainless-steel exacerbate the influence of grain boundaries on the graphene adsorption state. The correlation between stainless-steel grain boundaries and graphene frictional behavior provides insight into the application of graphene on stainless-steel surfaces.