マクロX線フラクトグラフィ

破壊解析法

抄録

X-ray broadening measurements were performed on various fracture surfaces by using a parallel beam method. A large X-ray exposed area (2×5mm²: the counter method and 1mm in colimeter diameter: the film method) was employed to eliminate the crystalographic local data scattering which would appear if a small X-ray exposed area (such as the microbeam method) were used. The following results were obtained.
(1) X-ray broadening can be expressed as a function of fracture stress intensity. In the case of fatigue crack propagation, the broadening depends on the stress amplitude rather than the maximum stress. In the case of program load fatigue, it depends on the stress amplitude that caused a larger crack propagation area.
(2) A quantitative analysis can be carried out even though fracture is the intergranular crack type. Also, this method is applicable even for the fatigue fracture analysis on the surface having no striation.
(3) This method is effective even for slightly corroded fracture surfaces on which only the corroded surface film is detectable by the scanning electron microscope.