Effect of WC addition on sliding wear behavior of SiC ceramics

The wear behavior of silicon carbide (SiC) ceramics prepared with 0, 10, 30 and 50 wt% tungsten carbide (WC) particles was studied in unlubricated sliding conditions against SiC ceramic balls at 5-, 10- or 20- N load. The coefficient of friction (COF) varied from 0.5 to 0.4, whereas the wear volume increased from 5.3×10−2 mm3 to 8.5×10−2 mm3 in the investigated sliding wear conditions. There was a negligible effect of WC addition on the frictional behavior of SiC ceramics; however, the specific wear rate decreased by one order of magnitude (from 3.8×10−5 to 3.3×10−6 mm3/N.m) with increasing WC content from 0 to 50 wt%. The SiC-50 wt% WC composite with a fracture toughness of 6.7 MPa.m1/2 and a hardness of 24 GPa exhibited superior wear resistance among the investigated composites. The material was mainly removed by cracking and pull-out when SiC-WC composites were worn in the selected sliding conditions. The experimentally measured wear volume was in accordance with that computed using a mechanics-based blunt indenter model.