The damage evolution of an extruded AZ31 magnesium alloy in uniaxial stress-controlled low cycle fatigue is investigated using a quasi-in-situ method. In the three studied samples, that is, slipping dominated (SD), twinning/detwinning/basal slipping (TDBS), and twinning/detwinning/slipping (TDS), the fractions of slip bands and/or twins keep increasing till a critical cyclic number, and are essentially unchanged in the subsequent cycles. Inter-granular micro-crack initiation is found to be favorable in the TDS and SD samples. While both the inter-granular and intra-granular micro-cracks are detected in the TDBS sample. Moreover, the non-Schmid behavior in the crack trans-granular propagation path is investigated.

使用准原位方法研究了挤压 AZ31 镁合金在单轴应力控制的低周疲劳中的损伤演变。在三个研究样本中，即滑动主导（SD）、孪晶/去孪晶/基底滑动（TDBS）和孪晶/去孪晶/滑动（TDS），滑动带和/或孪晶的比例不断增加，直到一个临界循环数量，并且在随后的循环中基本不变。在 TDS 和 SD 样品中发现晶间微裂纹萌生是有利的。而在 TDBS 样品中检测到晶间和晶内微裂纹。此外，研究了裂纹跨晶传播路径中的非施密德行为。