1998 Volume 41 Issue 3 Pages 422-429
The residual stress distribution of ground ceramics was determined from the eigen strain distributed near the ground surface. The eigen strain of ground ceramics was tensile, and exponentially decreased with the distance from the surface. The residual stress distribution is given as a superposition of an exponential function of compression and a linear function. It is found that the actual residual stress distribution can be approximated by an exponential function of compression because the magnitude of tensile residual stress is negligibly small compared to the compressive residual stress. In the experiments, the diffraction angle was measured on ground silicon nitride for a wide range of sin2 ψ using the glancing incidence X-ray diffraction technique. A strong nonlinearity was found in the 2θ-sin2 ψ diagram at very high ψ-angles. From the analysis of nonlinearity, the residual stress distribution was determined. The residual stress distribution of silicon nitride coincided with the distribution calculated from the eigen strain distribution. Transmission electron microscopy was used to clarify the origin of generation of the residual stress. Both strain contrasts and microcracks were observed below the ground surface;straight dislocations were also observed within silicon nitride grains near the ground surface.