1986 Volume 35 Issue 394 Pages 749-754
The X-ray diffraction method was used to measure the residual stress in the surface layer of sintered alumina finished under various conditions. X-ray elastic constants were determined for the diffraction lines of (1.0.10) plane and (220) plane obtained by using CrKα radiation. Those values were nearly identical for the as-fired surface, ground surface and lapped surface. The measured residual stresses were all compressive for various surfaces. The residual stress was the maximum compression of about -140MPa for the surface ground with #300-diamond wheel. The surfaces finished by #600-diamond grinding and lapping were about -90MPa. The residual stress measured on the fracture surface was small compression. Both the full width at the half maximum of diffraction profiles and the feature of X-ray microbeam diffraction patterns changed depending on the amount of plastic deformation associated with surface finishing and fracture processes.