Friction reduction mechanisms of TiN film sliding in graphene aqueous dispersion

The lamellar structure and weak interlayer shear force of graphene endow itself potential application value in lubrication fields, while its lubrication performance has been vastly investigated in various fields. However, there are few studies on the composite tribological performance of graphene and ceramic films. In this study, a solid–liquid lubricating system which TiN film slides in graphene aqueous dispersion is developed, aiming to achieve low friction of the TiN ceramic film in macroscale contact. Two kinds of TiN films were obtained by multi-arc ion plating and magnetron sputtering respectively. The tribological test show that the friction coefficient of the TiN film drops when adding graphene aqueous dispersion and varies with the concentrations of graphene. The results indicate that the graphene might act in two ways to achieve low friction of TiN film, which are liquid lubricating effect of solvents and the formation of smooth sliding interface promoted by graphene.