J Mater Sci Technol ›› 1998, Vol. 14 ›› Issue (3): 211-214.

• Articles • Previous Articles     Next Articles

Cyclic Saturation Dislocation Pattern Observation in the Vicinity of Grain Boundaries by Electron Channeling Contrast Technique

Zhefeng ZHANG; Xiaowu LI Huihe SU and Zhongguang WANG   

  • Received:1998-05-28 Revised:1998-05-28 Online:1998-05-28 Published:2009-10-10

Abstract: State Key Laboratory for Fatigue and Fracture of Materials, Institute of Metal Research, Chinese Academy of Sciences,Shenyang, 110015, China)Abstract:The cyclic saturation dislocation patterns within grains and in the vicinity of low-angle grain boundaries in fatigued copper crystal were successfully observed by electron channeling contrast technique in SEM. The results show that the dislocation patterns within grains consisted of typical two-phase structure, i.e. persistent slip bands (PSB) and veins. With increasing plastic strain amplitude (γp1 ≥1.7×10-3), large amount of PSBs and regufar dislocation walls were observed.The dislocation walls and PSBs could cross through the low-angle grain boundaries continuously except that the dislocation-free zone (DFZs) appeared at some local regions. Combining with the cyclic stress-strain response and dislocation patterns, the effect of low-angle grain boundaries on cyclic deformation behavior was discussed.