Tribological behavior of spark plasma sintered and laser ablated SiC- graphene nanoplatelets composite

Abstract

The silicon carbide (SiC) ceramic material was prepared by powder metallurgy processing route using spark plasma sintering (SPS) technique without any sintering additives. The effects of the SiC surface ablation by fiber laser and subsequent superficial incorporation of graphene nanoplatelets (GNPs) into the created microcraters were investigated in terms of their influence on the resulting tribological (i.e., friction and wear) behavior of the created SiC-graphene composite surfaces. It was clearly shown that the used laser treatment with the pulse duration in ms range led to desirable surface morphological changes, i.e., the creation of SiC ablated microrelief, suitable for GNPs incorporation. The friction and wear behavior of produced SiC-graphene composite surfaces was studied using translational ball-on-disc nanotribometer at room temperature and applied loading up to 1000 mN. The results showed that at all normal loads the wear rates of laser ablated surface materials were gradually decreasing as a result of frictional coefficient reduction. The observations of wear track topography indicated abrasive wear to be the dominant wear mechanism of the sintered SiC material. However, by incorporation of GNPs, the abrasive wear was significantly reduced by the graphene friction film created on the ablated SiC-graphene composite surfaces.