Relationship between Strength Degradation and Grain Depth of Cut during Grinding Si₃N₄

Abstract

The strength degradation of silicon nitride ceramics up-cut surface ground under different conditions were studied by specific grinding energy and maximum grain depth of cut statistically analyzed by new direct evaluation method of successive cutting point spacing. Main results are summarized as follows; (1) Strength decreases with increase in wheel depth of cut and with decrease in specific grinding energy, and dose not depend on the change of table speed under the grinding conditions with a wheel including large grain size (#100; grain diameter=125-150μm). (2) Strength degradation is much large by 70-80% compared to inherent strength of the work at the range of more than 0.5-1.0μm in mean value of maximum grain depth of cut.