Unlubricated wear of Si/SiC and its composite with nickel Si/SiC-Ni

Using a pin-on-disk tribometer, dry friction and wear properties at different temperatures were investigated for reaction-sintered silicon carbide Si/SiC and its composites with nickel Si/SiC-Ni. The friction and wear properties of the composites are improved by the addition of nickel. The analysis on the worn surfaces and sub-surfaces by SEM suggest that shallow grooves are the main wear feature at 15°C. At 600°C, surface cracking and fracture is the predominating wear mechanism for Si/SiC, and the formation of flake pits on the surface due to crack propagation at subsurface is the main wear mechanism for Si/SiC-Ni. Finally the relationships between wear resistance and mechanical properties are discussed.