Tribological behaviour of self-lubricating Mg matrix composites reinforced with silicon carbide and tungsten disulfide

In this study, magnesium matrix composites reinforced with 5 wt% WS2 and 15–20 wt% SiC particles were sintered via powder processing. The friction and wear behaviour were studied using a ball-on-disc tribometer against Al2O3 ball, subjected to normal loads of 1–4 N, room temperature and 110 °C, sliding speed of 22.5 mm/s, and lubricant of PAO base oil. The wear track and tribo-layer generated were investigated by optical profilometry and scanning electron microscopy. The average friction coefficient for Mg metal matrix composites (MMCs) was found to be 0.1–0.2 compared with 0.16–0.46 for pure Mg. Under all testing conditions, the Mg MMCs exhibited much lower friction coefficient and outstanding anti-wear property compared with unreinforced Mg and the Mg alloy AZ31