308 予疲労6061-T6 Al合金の動的引張り破断後の微視的表面観察(OS 材料・構造の動的特性(2))

抄録

After unexpected failure, the fractured material surface will be investigated with SEM (scanning electron microscope) to find the cause of the failure. In this paper, we tried to distinguish the loading histories of the dynamically fractured 6061-T6 aluminum alloy by observing the side surface with SEM. The alloy was fractured by dynamic tension (ε=l×10^3s^<-1>) with and without low-cycle pre-fatigue. On the side surface of the specimen, neighboring fractured surface, relatively large cracks bigger than, for example, lOμm were existed. The number of cracks and the size of them were evaluated quantitatively. The number of the relatively large cracks for the pre-fatigued specimens is greater than that for the virgin specimens.