Sliding wear characteristics of Al–7Si–0.3Mg alloy with minor additions of copper at elevated temperature

In the present study, the effect of minor additions of copper (Cu) on the elevated temperature wear behaviour of A356 (Al–7Si–0.3Mg) alloy have been investigated using a high temperature pin-on-disc wear testing machine. Effect of alloy composition, normal pressures, sliding speeds and sliding distances on A356 alloy at constant temperature of 300 °C have been studied. The cast alloys and worn surfaces were characterized by SEM/EDX microanalysis. The results suggest that, the wear rate of A356 alloy increases with increase in normal pressures, sliding speeds and sliding distances in all the cases studied and decreases with 0.5%Cu addition level to the A356 alloy at the tested temperature. This is due to the partial refinement of α-Al dendrites and solid solution strengthening and precipitation hardening. The worn surface study indicates that, the formation of Fe-rich oxide layer between the mating surfaces during sliding improves tribological properties.