Synthesis and Tribological Properties of Graphene-Copper Nanoparticle Composites as Lithium Grease Additive

In this paper, the graphene-copper nanoparticle composites(GN/Cu NPs) were prepared by in situ chemical reduction in aqueous solution. The influence of pH value and the concentration of PVP on the particle size and structure of the GN/Cu NPs as well as the element distribution were analyzed via the scanning electron microscopy(SEM), the transmission electron microscopy(TEM), the X-ray diffraction(XRD), and the energy dispersive spectroscopy(EDS). The tribological properties of the grease with GN/Cu NPs composites have been studied by SRV-IV. It was found that compared to the base grease, the GN/Cu NPs composites could help to reduce the wear loss of the disk by 85.5% and the average friction coefficient by 15.5%. The test results clearly indicated that the addition of the GN/Cu NPs composites significantly enhanced the tribological properties of grease.