Abstract:In this study，the effects of current densities on tribological properties of composites were studied using MZL-200H high speed current-carrying friction and wear testing machine. The damage mechanism of composites was revealed by the worn surfaces analysis. The results show that electroless plating could effectively improve the interfacial contact ability of graphite and copper matrix，and the graphite phases doesn’t agglomeration，and uniformly distribute in the connected continuous copper matrix. The friction coefficient and wear rate of composites are significantly lower than that of pure copper，in which the friction coefficient decreases with an increase in current density，and the wear rate increased. A large number of arc ablation pits appeared on the wear surface with an increase in current density. A dense layer of molten and re-coagulated copper particles is attached in the pits，and the width and depth of wear scars are significantly improved. The main damage mechanisms of the composites are melting and arc erosion，which are accompanied by abrasive wear，adhesive wear and oxidation wear.