Effect of heat treatment on the tribological properties of Al-Cu-Mg/nanoSiC composites

In this study, the effect of heat treatment on the tribological properties of Al-Cu-Mg alloy reinforced with 4 wt.% SiC particles with 650 nm average particle size has been investigated. The age hardening process consists of solution treatment at 540 degrees C for 6h, followed by water quenching and ageing at different temperatures of 175,200 and 225 degrees C with soaking times of 3, 6 and 9 h. Hardness measurements were applied to monitor the precipitation effect and the aged samples were then subjected to wear tests under dry sliding conditions against steel and alumina counterfaces. The results showed that the reinforced material exhibits an enhanced ageing response compared to the unreinforced material in the same heat treatment conditions. The rate of ageing increases with increasing temperature; however, ageing at 200 and 225 degrees C for more than 6 h resulted in over-ageing. The best combinations for the enhanced tribological properties for the composite material were selected as 6 h ageing at 225 degrees C. The precipitation effect for this alloy can be enhanced by the small addition of SiC nanoparticles. Having a small amount of nanoSiC particles with fine precipitates inside the matrix further increases the hardness and wear properties. (C) 2013 Elsevier Ltd. All rights reserved.