The Influence of Graphite on Tribological Properties of the Bearings Embedded with PTFE

The tribological properties of several tin bronze embedded with graphite-PTFE composite solid lubricants were observed. It was found that the addition of graphite not only increase the wear resistance of bearings embedded with PTFE, but also decrease and steady their friction coefficient. The chemical composition, change of some main elements amount and morphology of transfer film on friction surface were analysed by means of XRD, XPS and EPMA. It was considered that graphite promoted PTFE transfering to friction surface and formed a evenly covering solid lubricant transfer film, then the adhesion wear of the contact interface is reduced effectively.