中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 20 Special 2 July 2010 |
as-extruded AZ31 magnesium alloy
（1. Department of Materials Science and Engineering, Korea University, Seoul 136-701, Korea;
2. School of Materials Science and Engineering, Seoul National University, Seoul 151-744, Korea）
Abstract:The low cycle fatigue(LCF) properties of as-extruded AZ31 Mg alloy were investigated under total strain amplitudes in the range of 0.4%−1.2% with strain rate of 1×10−2 s−1. Due to the twinning effect in compression during loading and the detwinning effect during unloading, the alloy showed an asymmetric hysteresis loop. The cyclic stress response exhibited cyclic hardening at high total strain amplitudes. The cyclic deformation behaviors were discussed using the Coffin-Manson plot, which divided the plastic strain amplitudes into the tension side and the compression side. Through the LCF tests that were started from either tension or compression under a total strain amplitude of 1.0%, the interaction between the twinning effect and dislocation was analyzed. The twinning effect during the LCF test and the variation of the dislocation density were investigated using optical microscopy and transmission electron microscopy, respectively.
Key words: AZ31 magnesium alloy; low cycle fatigue; twinning; dislocation
