The effects of graphene platelets fillers on the sliding wear of WC-Al2O3 composites

WC-Al2O3 composites with 0, 0.1 wt%, 0.5 wt% and 0.9 wt% graphene platelets were fabricated in order to compare their tribological behavior. Friction and wear results were obtained on the composite flats sliding against the WC-Co cemented carbide under 50 N load using a reciprocating ball-on-disk tribometer. The experimental results indicate that the compacted layers with cracks form on the wear surfaces of all the composite bulks. The WC-Al2O3 composites with 0.1 wt% and 0.5 wt% graphene platelets possess lower friction coefficient and wear rate, which can be attributed to the lubrication and protection of graphene tribofilm as well as their higher mechanical properties. Graphene tribofilm cannot form on the wear surface of WC-Al2O3 composite with 0.9 wt%, due to the agglomeration tendency of graphene and its lower mechanical properties.