Prestress Scratching on SiC Ceramic

Prestress scratching tests have been performed on polished surface of SiC ceramics under a Rockwell diamond indenter moving with uniform speed and constant normal load. Combining with acoustic emission testing, the scratching depth and the surface/subsurface damage were investigated under the action of different prestress values. The results showed that the existence of prestress should shorten the depth of median cracks and reduce the subsurface damage, moreover, with increasing prestress in a proper range, the depth of median crack was decreased and the propagation length of lateral crack was limited.