細束X線による金属材料の変形および破壊に関する研究(第一報)　(細束X線技術の概念および引張変形への応用)

Abstract

Many investigations on mechanisms of the fatigue crack propagation have been made in macroscopic field. Especially, it was evident that the crack propagations were good correlated with characteristic features at the tip of crack in those investigations. On the other hand, it is very interesting to research the crack propagation from microscopic field such as the relation between stress and the strength of the crystallines ahead of the tip of fatigue cracks. Now, it is well known that the crystallines of the tip of crack are in the state of work hardening, and there is close correlation between work hardening and dislocation density, too. In this paper, to obtain the strength of the crystallines at the tip of crack, the authors investigated the relation between flow stress and excess dislocation density by means of X-ray microbeam diffraction technique.