Wear Mechanism of Reaction-sintered Silicon Carbide Composites in Dry Friction Condition

Si/SiC and Si/SiC Ni composites were prepared by reaction sinter technique. The friction and wear behaviors of the composites under dry sliding from room temperature to 600 ℃ were investigated on a pin on disk tribometer. The morphologies of the worn surfaces and cross sections of the composites were examined by means of scanning electron microscopy so as to explore the wear mechanisms. The results indicate that the reaction sintered Si/SiC Ni composites show improved friction and wear properties as compared with Si/SiC composites. The wear of Si/SiC composites is characterized by micro cutting and plowing at ambient temperature which turns into cracking and surface fracture at 600 ℃. The wear of Si/SiC Ni composites are dominated by sub surface cracking and the resultant localized spalling on the worn surface.