70/30黄銅の低サイクル疲労における粒界き裂の発生と転位組織
1993 年 59 巻 560 号 p. 910-915
詳細
1993 年 59 巻 560 号 p. 910-915
The mechanism of grain boundary (GB) crack initiation in low-cycle fatigued 70/30 brass is investigated on the basis of the observation of dislocation structures and surface topography by means of transmission and scanning electron microscopy. The dislocation structures are almost the same as those observed in a high-cycle fatigue test. Although typical dislocation structures are not indicative of strain localized regions (SLRs), the SLRs are recognized in the favorably oriented grains. At the intersections of such SLRs with the GB, extrusion-type GB deformations are frequently observed. These GB deformations are considered to be responsible for GB cracking. Based on the observations, the possible mechanism for the GB cracking in low-cycle fatigued 70/30 brass is discussed.
