The occurrence of ultralow friction even superlubricity for graphene oxide/hydrogenated diamond-like carbon composites in multi-environments

Abstract

The establishment of ultralow friction and superlubricity can significantly decrease the dissipation of energy and failure of parts in moving mechanical systems. Hydrogenated diamond-like carbon (H-DLC) film can realize the frictionless state at engineering scale by the stress-induced graphitization that leads to the formation of the vital superlubricious structures: graphene-like carbon and onion-like carbon during the sliding process. Herein, we designed some composites by combination H-DLC film and graphene oxide (GO) nanosheets to provide the “pre-graphitized” sliding interface for decreasing the friction. Frictional behaviors of these composites in different atmospheres and the as-formed structures of sliding interfaces were investigated comprehensively in this work. It was demonstrated that the existence of GO on H-DLC film could significantly decrease the friction and even establish the near friction-vanishing state. The structural investigations showed that the existence of GO on H-DLC film could work as a “pre-graphitization” process, hinder the structural evolution of H-DLC film from amorphous to sp2-rich ones and endow the composite with ultralow friction even superlubricious performance. The investigation would provide some helpful advices for H-DLC film to establish ultralow even superlow friction from inert atmospheres to humid air at engineering scale by depositing GO flakes on the surface of H-DLC film.