1988 年 37 巻 413 号 p. 210-215
The X-ray stress measuring method was applied to investigate a residual stress distribution in the ground surface layer of Si3N4 ceramics and its thermal stability. Residual stress in a heavily ground layer was measured using the diffraction lines (212), (321), (301) and (210) which appear at 131°, 117°, 81° and 54° in 2θ, respectively, by using CrKα radiation. Successive layer removing by lapping and subsequent X-ray stress measurements revealed that compressive residual stress existed throughout the deformed layer which was restricted up to the depth of 20μm even in the case of a heavy grinding condition. There existed a diffraction plane dependence of the measured residual stress values.
In order to investigate the thermal stability of residual stress, the specimens were annealed for an hour at each temperature ranged from 770K to 1770K in an argon atmosphere. Annealing below 1000K did not change the initial lattice strain state nor the initial diffraction line width. This means that both macro- and micro-residual stresses are stable at such high temperatures.