We used X-ray diffraction method using Synchrotron radiation (SR) for solving residual stress in composite material. Diffraction planes with arbitrary diffraction angle were measured. Moreover, there is a characteristic that the different diffraction planes at same 2θ angle were obtained using SR with different wave length. In this study, effects of penetration depth on an X-ray parameter of the composite material were examined. First of all, the X-ray elastic constant of the single-phase body (PXEC) was measured for the evaluation of the phase stress. Next, the elastic deformation behavior of phase stress in the matrix phase was evaluated, and the influence of the second phase particle was investigated. Residual phase stress of each phase in the fracture surface is measured as an application example for the X-ray Fractography. The relation between the stress intensity factor and TiN volume fraction was examined.Trying to fracture toughness test in composite material, we discussed influence of fracture toughness value on residual stress. Deformation behavior of softer matrix phase was controlled by hard second phase particle under macroscopic tensile stress. It was found that residual stresses in the fracture surface were relaxed on the surface.Furthermore, there is the correlation between the stress intensity factor at the fracture and the phase stress in the matrix phase.
