Abrasive Surface Deformation of Sapphire

Abstract

The depth of slip and the size of deformation twins introduced into sapphire by abrasive grinding depend on surface orientation. Enhanced depths of slip minimize surface chipping and striations, and grinding can result in basal slip depths of 30 μm and twins 75 μm in size. Basal twins in nonbasal surfaces are largest for single‐point diamond abrasion directions parallel to a 〈1100〉 basal twin shear direction, whereas optically detectable rhombohedral twins are produced only in 30° and 60° surfaces.