Dry sliding wear behaviour of aluminium-lithium alloys reinforced with SiC particles

Several wear tests were carried out at different pressures and temperatures on Al-8090 and Al-8090 + 15 vol.% SiCp. Worn specimens and debris were also examined using SEM and EDX techniques to identify the dominant wear mechanisms. Wear rate increases about two orders of magnitude when temperature is above a critical one. The transition from mild to severe wear is dependent on nominal pressure. The composite transition temperature is higher than that of the unreinforced alloy. Within the mild wear regime, the wear rates for both materials exhibit a minimum over 100 °C and are higher for the composite material than for the Al-8090 below the transition temperature. It has been also observed that the presence of mechanically mixed layers (MML) on the wear surface with varying morphology and thickness influenced the wear rate. The morphology and composition of the wear debris also change with the wear mechanism.