Influence of Strain Distribution in X-Ray Irradiated Area on Diffraction Profile
Yoshiaki AKINIWA and Masahiro AMANO
Abstract:When the elastic-plastic strains vary according to its location in an irradiated area, the stress/strain and the damage measured by X-ray method are different from those obtained from specimens deformed uniformly. In this study, influence of the distribution of the elastic-plastic strains in the irradiated area on diffraction profiles was investigated by using a numerical approach. The change of the full width at half maximum, ĢH, could be approximated as a function of plastic strain. For the distribution of the elastic strain, the value of ĢH increases with increasing range of the elastic strain in spite of absent of plastic strain. When the diffraction profile was approximated by the pseudo-Voigt function, the weight coefficient of Lorentzian decreased with increasing range of the elastic strain. For the crack problem, the distribution of the elastic strain calculated from the diffraction angle agreed well with the average value within the irradiated area. The elastic strain took the maximum at half distance of the irradiated size ahead of the crack-tip. For the large irradiated area, the value of ĢH decreased and took the maximum value behind the crack-tip. Key Words:X-ray diffraction, Elastic-plastic strain distribution, Line broadening, Pseudo-Voigt function, Crack