Neutron Diffraction Study of Thermal Residual Stress in Ceramic Composite

抄録

The residual stress in ceramic composites of alumina mixed with various volume fractions of zirconia, Al₂O₃/ZrO₂, and of silicon carbide, Al₂O₃/SiC, was measured by the neutron diffraction method. The thermal residual stress of each constituent phase was measured as a function of the second phase. The phase stresses were determined from the neutron diffractions of ZrO₂ 202, Al₂O₃ 113, Al₂O₃ 116, SiC 220 and SiC 311. In Al₂O₃/ZrO₂ composites, the residual stress in the alumina phase was compression and that in the zirconia phase was tension. On the other hand, in Al₂O₃/SiC composites, the residual stress in the alumina phase was tension, and increased linearly with the silicon carbide volume fraction. The residual stresses were introduced by the mismatch of the coefficient of thermal expansion. The change of the residual stress with volume fraction of the second phase agreed well with the theoretical prediction based on Eshelby's inclusion model.