Enhancement of hydrogenated graphene on mechanical and adhesive properties of diamond-like carbon films

Abstract This paper aims to investigate the mechanical and adhesive properties of diamond-like carbon films substrate covered by hydrogenated graphene (HG) using molecular dynamics simulations. For the mechanical properties, compared with the bare substrate, the HG-covered substrate shows a remarkable reduction on the out-of-plane stiffness, but shows an improvement on the maximum indentation force. For the adhesive properties, the suppression of covalent bond at the contact interface reduces the interfacial adhesion. These properties of the HG-covered substrate are strongly dependent on the hydrogenation degree of HG and its number of layer due to the sp2-sp3 hybridization of carbon atoms and relative motion between the graphene layers. This finding provides a route for designing the novel solid lubricants with excellent wear-resistance performance.