Friction and wear behavior of Al-SiC(n) hybrid composites with carbon addition

Aluminum matrix composites with heterogeneous reinforcement of SiC nanoparticles (SiC(n)) and carbon (multiwalled carbon nanotubes or glassy carbon particles) were manufactured via mechanical alloying of the composite powder followed by hot pressing at the semi-liquid state. The existence of both carbon forms altered the tribological behaviour of the composites since the noteworthy wear reduction was observed in comparison to the carbon-free composites. The stabilization of friction coefficient occurred in glassy carbon modified composites and was detected during the room- and high-temperature wear test. Moreover, the glassy carbon addition in the Al-SiC(n) composite modified its wear behaviour at 450 °C in such a way that a significant decrease of the composite wear rate was observed and the process was accompanied by the considerable mass transfer of metal from the counter specimen. The mechanism behind the noteworthy wear of the glassy carbon modified hybrid composites is proposed.