Preparation, friction, wear, and fracture of the Si3N4-Ag-GNPs composites prepared by SPS

Abstract Silver and graphene nanoplatelets (Ag-GNPs) have been employed as reinforcements to prepare the self-lubricating silicon nitride matrix composites via 3D ball milling (Turbula) and spark plasma sintering. The prepared composites were characterized by scanning electron microscope with energy dispersive spectroscopy, Vickers hardness tester and reciprocating ball tribometer. Fracture surface morphology of the sintered composites indicated the potential reinforcement by the ductile silver phase. The mechanical property testing revealed that Si3N4 composites with Ag and GNPs incorporation exhibited lower hardness and slightly lower toughness compared with Si3N4 monolithic material. However, the coefficient of friction and wear in composites exhibited the lower values in 1 N friction force testing range.