RESIDUAL-STRESS IN CERAMICS WITH LARGE THERMAL-EXPANSION ANISOTROPY

Residual stress was measured in sintered and heat-treated Fe2TiO5 samp les with various grain sizes. The influence of texturing was assessed by comparing the residual stress states of samples having randomly ori ented grains and highly oriented grains produced through magnetically assisted processing. The residual stress was measured with x-ray diffr action using CrKalpha radiation. Due to the significant texture and th e consequential oscillations in the d(phi psi) vs sin(2) psi data, the residual stress was calculated using the Marion-Cohen method. Texture d samples showed significantly lower residual stresses except when spo ntaneous microcracking accompanied grain growth in the randomly orient ed systems. Elastic modulus measurements showed a direct correlation b etween the decrease in residual stress and the microcrack density.