Tribological properties of Al-20Si-5Fe-2Ni-Graphite solid-lubricating composites

Solid-lubricating composites show great potential for tribological applications. In this study, the Al-20Si-5Fe-2Ni-Graphite composites with 0-30 wt. % copper-coated graphite were fabricated by spark plasma sintering. Effect of Cu-coated graphite on the phase, microstructure, hardness, strength and dry sliding wear behavior of the composites was investigated. The results indicated that the formation of Al2Cu interface can enhance the mechanical properties of the composites. The friction coefficient and wear rate of the composites were dependent on the amount of copper-coated graphite and applied load. The composite containing 30 wt. % Cu-coated graphite exhibited the lowest friction coefficient and wear rate. The related mechanism was discussed.