Formulation for the Effect of Surface Grinding on Strength Degradation of Ceramics

Abstract

Relationship between fracture strength of ground ceramics and maximum grain depth of cut, g, has been formulated. The strength was expressed by an exponential function of g. This expression is based on the assumption that the crack depth of the ground specimen is represented in terms of normal grinding force applied with a single abrasive grain of a wheel, as median crack length in indentation fracture is the function of indenting load. The four-point bending strength of sintered silicon carbide ceramics ground with 4 kinds of grit diamond wheels under various conditions showed good agreement with the approximation by the function of g. In particular, the strength decreased steeply from the inherent level with a slight increase in g.