Grindability of Various Silicon Nitride Ceramics

Abstract

The grindability of various silicon nitride ceramics ground using different diamond grinding wheels was evaluated in terms of specific grinding energy and strength degradation. Main results are summarized below. (1) Specific grinding energy increases with increasing hardness of the workpiece material using a grinding wheel of small grain size under the condition of small wheel depth of cut. (2) Strength degradation increases with a grinding wheel of large grain size. Degradation increases with a smaller material constant of the critical indentation radius: E⋅Kc2/Hv3 (E: Young's modulus, K1c: fracture toughness, Hv: Vickers hardness). (3) The degradation increases with increasing mean value of maximum grain depth of cut. The strength in the region of a large mean value of maximum grain depth of cut decreases with a larger material constant of crack extension length: Hv1/4/Kc.