Room and high temperature reciprocated sliding wear behavior of SiC-WC composites

摘要

Hot pressed silicon carbide (SiC) composites prepared with 10, 30 or 50 wt% tungsten carbide (WC) were subjected to unlubricated reciprocating sliding wear against SiC balls at 19 N load at room temperature and 500 degrees C. The coefficient of friction decreased from 0.4 to 0.3 with WC content at room temperature. The wear rate varied from 1.5 x 10(-6) mm(3)/N m to 4.2 x 10(-5) mm(3)/N m with change in temperature or WC content. SiC-WC composites exhibited maximum wear resistance with 50 wt% WC at room temperature and 30 wt% WC at high temperature. Worn surface analysis indicated tribochemistry and microfracture as material removal mechanisms for sliding in ambient conditions, whereas microfracture dominated at 500 degrees C. Wear results obtained at high temperature are consistent with the lateral fracture model for wear volume estimation.