Friction and wear mechanisms of hot-pressed SiC-in situ Zr2CN composites in extreme conditions of humidity and temperature

Abstract

Hot-pressed SiC-in situ Zr₂CN composites were subjected to sliding against SiC counterbody in varying conditions of humidity (≤20 % RH and ≥90 % RH), and temperature (25 °C and 500 °C). Results demonstrated that sliding friction and wear decreased with increasing ZrN content from 0 to 10 vol% in the initial powder composition. Wear resistance increased by 37% at dry, 79% at humid and 54% at high temperature condition for the composite with 10 vol% initial ZrN content in comparison to monolithic SiC ceramics. While the presence of Zr₂CN phase in SiC ceramics reduced fracture and pull-out, friction and wear are found to be minimum at humid condition due to the formation of thick tribo-oxidative layer at the contact. Results obtained from this study indicate the potential aspects of SiC-10 vol% ZrN composites in tribological applications where material in sliding contacts experiences extreme conditions of humidity and temperature.