摘 要由于AZ31 镁合金是密排六方晶体结构，滑移系少，室温下塑性较差，目前人们主要通过细化晶粒来提高其强度和塑性。开发新的高性能镁合金系列是目前讨论的主要趋势，但对现有镁合金系统进行适当的工艺处理也可能成为改善材料性能的廉价而有效的方式。由于低温塑性变形过程中容易导致裂纹的产生，加之镁合金塑性较差，因此有关镁合金在低温情况下变形的讨论很少。为此，本文讨论了室温下AZ31 镁合金线材的拉拔工艺，并获得了超过60%的最大累积冷变形程度。之后对不同冷变形程度的线材进行了不同工艺的再结晶退火处理。采纳金相显微镜（OM ）对各种退火线材进行了微观组织观察，截线法测定了其晶粒尺寸，获得了退火工艺与再结晶晶粒尺寸的关系。采纳Instron5567 对不同工艺下的线材进行了室温拉伸试验，测定了其力学性能。关键词: 镁合金，冷拉拔，再结晶退火，显微组织，力学性能AbstractBecause of the hexagonal closed packed (HCP) crystal structure and lack of enough slip systems, AZ31magnesium alloy possesses poor formability at room temperature. Grain refinement is known to be an effective method to improve the poor mechanical properties in recent years. Now, the important fields about magnesium alloy are to explore some new magnesium with high properties. But appropriate processing treatment with magnesium is probably to be an effective and low-cost method of improving their properties. Crack can easily appears at low temperatures,which leads to poor properties of magnesium, thus research on magnesium at low temperatures is very few. In this paper, studyoncold drawing at room temperature and annealing process at various temperatures of AZ31 magnesium alloy were carried out. Effects of annealing process on grain refinement of AZ31 magnesium alloy were analyzed in this paper. Tension test was applied on various-processed AZ31 Mg alloy wires using Instron5567 tension machine.Keywords ： AZ31 magnesium alloys, cold drawing, annealing, microstructure, mechanical prop...
