Experimental investigations of machining characteristics and removal mechanisms of advanced ceramics in high speed deep grinding

Machining characteristics and surface integrity of advanced ceramics, including alumina, alumina-titania, and yttria partially stabilized tetragonal zirconia, were studied under high speed deep grinding conditions. Material removal mechanisms involved in the grinding processes were explored. The material removal in the grinding of alumina and alumina-titania was dominated by grain dislodgement or lateral cracking along grain boundaries. The removal for zirconia was via both local micro fracture and ductile cutting. It was found that under a feed rate of 500 mm/min and for all the wheel speeds used, an increase in the wheel depth of cut (DOC) from 0.1-2 mm slightly improved the ground surface finish, but greatly prolonged the wheel life. This increase did not deepen the subsurface damage layer for the alumina and alumina-titania, but resulted in a slightly deeper damage layer for the zirconia. (C) 2003 Elsevier Science Ltd. All rights reserved.