OS08W0193 Sliding wear of silicon carbide and silicon carbide-graphite composite ceramics

Abstract

A monolithic SiC ceramic and two SiC-C composite ceramics containing 10vol% and 20vol% of graphite were prepared by hot pressing. The friction and wear behaviors of these materials were evaluated by sliding against sintered silicon carbide under dry conditions using two tribometers: block-on-ring and pin-on-disk. For all the three materials, worn surface was smooth and wear was mild in block-on-ring tests, whilst worn surface was rough and wear was severe in pin-on-disk tests. In the block-on-ring tests, addition of graphite into SiC concurrently achieved a reduction in friction and an increase in wear resistance; however in the pin-on-disk tests, the addition of graphite led to sharply enhanced wear rates despite the lowered friction coefficients.