TRIBOLOGICAL BEHAVIOUR OF GRAPHENE NANOSHEETS AS LUBRICANT ADDITIVE

In this study the tribological behaviour of graphene nanosheets in a mineral oil was investigated under very wide spectrum of conditions, from boundary and mixed lubrication to the elastohydrodynamic regimes. To explore the performances of the grapheme oxide nanosheets, prepared by a modified Hummer method, a rotational tribometer with a ball on flat setup has been employed. The excellent friction and anti-wear properties of graphene sheets may possibly be attributed to their small structure and extremely thin laminated structure, which offer lower shear stress and prevent interaction between metal interfaces. The results clearly prove that graphene platelets in oil easily form protective deposited films to prevent the rubbing surfaces from coming into direct contact and, thereby, improve the entirely tribological behavior of the oil.