(2) by bending rolling find different bending mode have a significant impact on twins and mechanical properties of AZ31 magnesium alloy rolled stock. Extending repeatedly bending roll rate 8.47%, the yield strength and tensile strength were 155MPa and 295MPa, and flat-rolled rolling and bending elongation of 15.6%, while the tensile strength of the material reaches 330MPa. The number of twins and less of the former and more stretched form twins, and upper and lower surfaces of the material which has a small amount of fine-grained layer, which is caused because at the grain boundaries and twins in the grain refinement, thus bend + flat rolling process can significantly improve the elongation of magnesium alloys.

(3) by rolling different ratios found different ratio has a significant impact on twins and mechanical properties of AZ31 magnesium alloy rolled stock. Comparison of different different ratios found in different ratio of 1: 1.25 can significantly increase the elongation of the magnesium alloy material and reducing the yield strength, the elongation of 24.09%, the yield strength and tensile strength were 114MPa and 275MPa, the resulting sheet material twinning is much less than synchronous rolling, drawing mainly twins, because asynchronous slip systems easier to start rolling, the twins not easily occur, so asynchronous rolling a magnesium alloy can be improved to a certain extent the plastic deformation. Which is to expand the scope of application of magnesium alloy, it has a very important significance.

Because there is a big stress factor rolled plate, we use a variety of methods have failed to complete EBSD observation, hoping to achieve a breakthrough on this in the future.

Keywords：magnesium alloy；Twins；Rolling

 目  录

第一章 绪论 1

1.1  镁及镁合金简介 1

1.1.1 镁及镁合金 1

1.1.2 变形镁合金 2

1.2  镁合金的塑形变形机制 2

1.2.1 位错滑移 2

1.2.2 孪生 3

1.2.3 晶界滑移 5

1.3  影响镁合金孪生变形的因素 5

1.3.1 变形温度 5

1.3.2 变形速率 6

1.3.3 晶粒尺寸 6

1.3.4 晶粒取向 6

1.4  孪生对塑性变形的影响 6

1.5  镁合金的轧制成形方法 7

1.5.1 常规轧制 7

1.5.2 叠轧 7

1.5.3 交叉轧制 8

1.5.4 等径角轧制 8

1.5.5 异步轧制 9

1.6  论文选题意义及内容 10

1.6.1 论文主要研究内容 10

第二章 实验材料及方案 11

2.1  实验材料 11

2.2  实验方案 11

2.2.1 镁合金板材轧制 11

2.2.2 力学性能 14

2.2.3 微观组织 15

第三章 实验结果与分析 16

3.1  表面纹理轧制对AZ31材料性能的影响