摘要镁合金是目前生活及生产应用用最为广泛的轻质结构材料。镁合金因其良好的铸造性、抗腐蚀性及尺寸稳定性高等特点在航天领域、汽车、国防事业、电子等产业中具有广阔的应用前景。因为现有工业所加工的镁合金普遍存在强度低、塑性差等不足，因而本文通过对制备Mg-3Al-1Zn合金的加工工艺进行改进探索，形成降温变面轧制工艺方式，以此来加强Mg-3Al-1Zn合金的综合机械性能。试验过程当中我们通过金相显微镜、透射电子显微镜和衍射仪等察看降温变面轧制后Mg-3Al-1Zn合金的微观构造和常规变面轧制后的Mg-3Al-1Zn合金对比发现微观组织发生很大改变，动态再结晶不足，晶粒没法细化且晶粒不能均匀分布，孪生大量产生。此外，通过单轴拉伸力学性能实验所测得的数据和微观组织情况结合分析发现降温变面轧制Mg-3Al-1Zn合金的强度增加，塑性升高且延伸率提高。25580
关键词 Mg-3Al-1Zn合金 动态再结晶 晶粒细化 孪晶 力学性能
毕业论文设计说明书外文摘要
Title Microstructure and mechanical properties of Variable- plane -rolled AZ31 magnesium alloy under decreasing temperture
Abstract
Magnesium alloy is a light structural material what used widely in life and production. Because of its good casting properties, corrosion resistance and dimensional stability, magnesium alloy has wide application in the field of aerospace, automotive, defense, electronics and other industries. But magnesium alloys made by traditional plastic machining have many disadvantages, In this paper, AZ31 magnesium alloys were processed by variable-plane rolling, cooling variable-plane rolling and variable-plane sheet rolling, in order to improve the mechanical properties of magnesium alloys.
In this lab, from the evolved microstructures that were observed by optical microscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD). we can find that the microstructures of variable-plane-rolled AZ31 magnesium alloy are changed obviously. Dynamic recrystallization occurs during deformation. Grain size is refined and homogeneous. The number of twins is increasing. In addition, the tensile strength of AZ31 magnesium alloy was significantly increased through the uniaxial tension and compression, the ductility and the elongation rate was also improved. And through the experimental contrast, it can be seen that the deformation temperature is decreased, the dynamic recrystallization is not enough, and the grain size is blocked.
Keywords AZ31 magnesium alloy Dynamic recrystallization Gain refinement Twin Mechanical properties
目 次
1 绪论 1
1.1 课题研究背景 1
1.1.1镁合金介绍 1
1.1.2 镁合金的分类及应用 1
1.1.3 镁合金的轧制工艺及研究现状 1
1.2 力学性能的影响因素 2
1.2.1 晶粒细化对镁合金力学性能的影响 2
1.2.2 织构对镁合金力学性能的影响 3
1.2.3 动态再结晶对镁合金力学性能的影响 3
1.3本课题的研究目的、内容及意义 3
2 实验方法 5
2.1 镁合金的制备 5
2.1.1 实验材料 5
2.1.2 降温变面轧制AZ31镁合金 5
2.2 力学性能测试 7
2.3 微观组织分析 8
2.3.1 金相组织观察 8
2.3.2 X射线衍射分析 9
2.3.3 扫描电子显微镜分析 9
2.3.4 透射电子显微镜分析 9
3 实验结果 10
3.1降温变面轧制AZ31镁合金 10 降温变面轧制AZ31镁合金组织性能演化:http://www.youerw.com/cailiao/lunwen_19430.html