中文摘要：

晶粒细化可以改善镁合金的强度和延性,通过控制轧制工艺可以控制变形组织.文中研究了不同轧制道次变形量对AZ31镁合金组织和性能的影响.实验结果表明：随着轧制道次变形量的增加,轧制应变速率增加,镁合金发生了动态再结晶,获得细小的晶粒组织,板材的硬度增加;但是,当轧制道次变形量增加到一定值之后,板材的表面出现宏观裂纹;采用大的道次轧制应变技术,可以减少轧制道次,制备晶粒尺寸为2～5μm的细晶镁合金板材.

英文摘要：

In the hot rolling of magnesium alloy, the grain refinement may result in the strength and ductility improvement, and the variation of rolling parameters helps to control the microstructure of the alloy. This paper focuses on the effects of the reduction per pass on the microstructure and properties of AZ31 magnesium alloy. The results show that, with the increase of the reduction per pass, the strain rate improves and a dynamic re-crystallization occurs, which results in the grain refinement and hardness improvement. However, surface cracks may occur when the reduction per pass increases to a critical value. Moreover, it is found that hot rolling with large strain may decrease the number of rolling passes. Thus, fine-grained AZ31 Mg sheets with a grain size of about 2 to 5 μm can be successfully prepared by hot-rolling with large reduction per pass.