▎ 摘　　要

The tribological properties of graphene (GN) and graphite (G) as lubricant additives in lithium greases were investigated with a four-ball tribotester. The micro-morphology as well as the content and chemical state of elements on the worn surfaces was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that the tribological performance of lithium grease could be significantly improved by the addition of graphene. During the friction process, an adhesion film and a deposition film consisted of graphene as well as a tribochemical reaction film composed of FeO, Fe2O3, FeOOH and LiOH could be formed on the tribosurface, and these complex films were responsible for the improved tribological performance of lithium grease.