Effect of impingement angle and WC content on high temperature erosion behavior of SiC-WC composites

Abstract

Hot pressed dense SiC-(0, 10, 30 or 50wt%)WC composites were subjected to erosion against SiC particles at 800°C. Effects of WC content and angle of impingement (30°, 60° or 90°) on the erosion performance of composites were evaluated. Erosion rate ranged from 2.1×102mm3/kg to 7.7×102mm3/kg with varying WC content or angle of impingement. The erosion rate of the composites increased with increasing the impingement angle from 30° to 90°, and decreased with WC content up to 30wt%. Minimum and maximum erosion wear rates were obtained for SiC-30wt% WC composites at 30° and for SiC-50wt% WC composites at normal impact, respectively. Grain fracture and pull-out were observed as major mechanisms of material removal for the composites. Decreased angle of impingement led to reduced grain fracture and pull-out, and hence reduction in material removal. Owing to increased fracture toughness with incorporation of WC particles, the composites showed less fracture and removal of WC particles up to 30wt% reinforcement.