Effect of SiC nanoparticles addition on mechanical properties and wear resistance of cemented carbides fabricated by spark plasma sintering

WC-10Co cemented carbides containing 1 to 4 wt% SiC nanoparticles were prepared by spark plasma sintering. The effects of SiC content on microstructure, mechanical properties and wear resistance of the sintered materials were studied. Microstructural studies showed that SiC addition resulted in WC grain coarsening. In addition, the hardness decreased with increasing SiC content. However, the fracture toughness and wear resistance significantly improved with SiC incorporation. The lowest wear rate (1 mm3/m) was attained for the nanocomposite reinforced with 2 wt% SiC. In the unreinforced cemented carbide, the extensive plastic flow of the Co binder and WC grain pullout led to a high wear rate (23 mm3/m). In the nanocomposite samples, solid solution strengthening of the Co binder by partial dissolution of SiC particles decreased the degree of plastic deformation on the worn surfaces. In addition, coarser WC particles within the nanocomposite samples exhibited a higher resistance against pullout resulting in the enhanced wear resistance.