Enhanced wear resistance of cemented carbides reinforced with SiC nanoparticles

Abstract

WC-10 wt% Co cemented carbides containing various amounts (0–4 wt%) of SiC nanoparticles were fabricated by vacuum sintering. The influence of SiC nanoparticles on microstructure, mechanical behavior, and dry sling wear resistance of the produced cemented carbides was explored. Results showed that SiC addition resulted in larger WC grains, thus lowering the hardness. Despite the hardness reduction, the wear resistance increased with increasing SiC content. The specific wear rate of the WC-10Co sample was 12.33 × 10−5 mm3/Nm that decreased to 1.86 × 10−5 mm3/Nm with 4 wt% nanoparticle addition. The improved wear resistance of nanocomposite samples was explained through the effects of SiC particles on modification of pore distribution, increased fracture toughness, and reduction of coefficient of friction. In the unreinforced WC-10Co cemented carbide, microstructural pores were found to be smaller but more numerous, resulting in extensive WC grain pullout. In addition, scuffing was recognized as the prevalent wear mechanism making friction trace completely unstable. In the nanocomposite samples, however, SiC nanoparticles stabilized and reduced the coefficient of friction. The change in friction condition from sliding to rolling abrasion revealed the microabrasive grooving as the predominant wear mechanism of the nanocomposites with enhanced wear resistance.