Dry sliding friction and wear behaviour of hypereutectic Al–Si–carbon fibre metal matrix composite

This work deals with the investigation on the friction and wear behaviour of as cast hypereutectic Al–Si alloy reinforced with copper coated short carbon fibres both before and after heat treatment. The composites are fabricated using liquid metallurgy route. Friction and wear tests were conducted using a pin on disc machine under dry conditions. The loads (contact pressure) and sliding velocities have been varied from 10 to 50 N (contact pressure of 0˙12–0˙60 MPa) and 0˙3 to 1˙2 m s^–1 respectively. Results reveal that coefficient of friction and wear rate of the composite are lower than that of the matrix alloy in both heat treated and unheat treated conditions. The coefficient of friction of the matrix alloy and its composite decreased with increased load up to 30 N and increased beyond this load. The wear rates of both the matrix alloy and its composite increased with the increasing load. However, at all the loads and sliding velocities studied, the developed composite exhibited a lower coefficient of friction and wear rates when compared with the matrix alloy. Energy dispersive X-ray analysis of the worn surfaces of Al–Si–2 wt-%C_f have revealed greater proportions of iron pick up from the counter steel disc when compared with the matrix alloy.