TRIBOLOGICAL BEHAVIOR OF ALUMINUM-ALLOY COMPOSITES - A COMPARATIVE-STUDY WITH A COPPER-BASED ALLOY

This paper describes the results of dry sliding wear tests of LM13 alloy and graphite-particle-reinforced LM13 alloy composite in cast and heat-treated conditions, and their comparison with a conventionally used copper-based bearing alloy. Sliding wear tests were conducted on a pin-on-disc wear test apparatus against a rotating steel(EN25) counterface at a sliding velocity of 2.68 m s-1. Results of the present investigation showed that the wear rate of the composite was considerably less than that of the copper-based alloy at an applied pressure of less than 4.0 MPa. Above 4.0 MPa the composite samples seized. However, the seizure pressure of the composite was less than that of the copper-based alloy. Detailed studies of wear surfaces, wear debris and subsurface deformation have been carried out. The overall results indicate that the heat-treated aluminium alloy-graphite composite could be considered as an excellent substitute for a conventional bearing alloy, such as Cu-Sn-Pb, at relatively low applied pressures (below 4.0 MPa), while the copper-based alloy can withstand higher pressures (up to 10 MPa).