Nanoscale wear mechanisms of few-layer graphene sheets induced by interfacial adhesion

The nanoscale adhesive wear of graphene was studied by molecular dynamics simulation of a diamond tip sliding over a few-layer graphene sheet. We obtained the typical adhesive wear tracks with initial rupture cavity induced by adhesive interaction between the tip and graphene. The coupled interaction, between the formation of interfacial bonds and the breakage of in-plane C-C bonds, leads to the usually observed severe damage of graphene after an adhesive wear process. Moreover, the critical contact pressure for onset of adhesive wear of graphene (∼42 GPa) is much lower than that for abrasive wear (∼94 GPa), which also cannot be correctly approximated by the onset condition for initial rupture of graphene during a loading process (∼76 GPa).