Study of Wear Properties of Al-SiC Composites

Abstract

Al–SiC composites containing four different weight percentages 5%, 10%, 20% and 25% of SiC have been fabricated by liquid metallurgy method. Friction and wear characteristics of Al–SiC composites have been investigated under dry sliding conditions and compared with those observed in pure aluminium. Dry sliding wear tests have been carried out using pin-on-disk wear test rate normal loads of 5, 7, 9 and 11 Kgf and at constant sliding velocity of 1.0m/s. Weight loss of samples was measured and the variation of cumulative wear loss with sliding distance has been found to be linear for both pure aluminium and the composites. It was also observed that the wear rate varies linearly with normal load but lower in composites as compared to that in base material. The wear mechanism appears to be oxidative for both pure aluminium and composites under the given conditions of load and sliding velocity as indicated by scanning electron microscope (SEM) of the worn surfaces. Further, it was found from the experimentation that the wear rate decreases linearly with increasing weight fraction of silicon carbide and average coefficient of friction decreases linearly with increasing normal load and weight fraction of SiC. The best results have been obtained at 20% weight fraction of 320 grit size SiC particles for minimum wear.