新型镁合金铆接技术研究（本科毕业论文设计）.doc

摘 要

镁合金由于其优异的性能而成为备受关注的新型材料。镁合金件在应用中难免会与其它材料的零部件连接，由于镁合金具有特殊的材料及腐蚀特性，其与异种材料结构件之间的连接技术成为制约镁合金广泛应用的障碍之一。近些年, 虽然也有人研究用焊接、钎焊或胶接等方法进行镁合金与异种材料的连接问题，但铆接技术由于其简单可靠、工艺成本低等优点仍是解决镁合金与异种材料连接的重要手段之一。
本研究主要针对镁合金发动机罩盖开发过程中遇到的压铸罩盖体与钢制板状零件的连接问题，开发了具有自铆特征的热压铆新技术，本文重点开展了不同温度（500 oC、600 oC和700oC）下对镁合金零件的压铆实验，然后对比不同实验参数下的压铆接头组织进行了分析。实验结果表明：随着压铆温度的升高，镁合金AZ91更易发生塑性变形，更易形成压铆接头。在压铆变形过程中出现动态再结晶，AZ91基体的铸态粗大树枝晶变成等轴晶，当变形温度升高和变形程度加大到一定程度，再结晶基本完全，晶粒分布均匀并得到显著细化。由于晶粒长大前后总的界面能差，压铆变形温度太高则会造成再结晶得到的无畸变等轴细晶粒继续长大变成均匀分布的粗晶粒。
总之，上述研究表明，600℃下进行压铆实验得到的镁合金接头质量最好，可以将此温度作为该铆接技术实际应用时所需温度的参考。


关键词：AZ91镁合金，铆接，变形，组织












ABSTRACT

Because of magnesium alloy’s superior performance it becomes a major concern of new materials. Magnesium alloy case will inevitably be in the application of the parts and other materials connected，as magnesium alloy is of special materials and corrosion properties，and heterogeneous structure of a link between technology as restricting the wider use of magnesium alloy one of the obstacles. In recent years，although some research welding, brazing or adhesive methods， such as magnesium alloy and the connecting dissimilar materials， but because of its riveting technology is simple and reliable， low cost technology is still resolve the merits of magnesium alloy and xenotransplantation Material linking one of the important means.
The purpose of this study for magnesium alloy engine hood covered encountered in the development of the casting hood covered with steel plate parts of the connection problems， developed a self-riveting characteristics of the pressing riveting new technologies， This article focus on a different temperature (500 ℃、 600℃ and 700℃) under the pressure of magnesium alloy components of riveting， and then compare different parameters under the pressure of the first organizations in a riveting analysis. The results showed that：With the temperature rising pressure riveting，magnesium alloy AZ91 more plastic deformation，the more pressure riveting first formed.Pressure riveting deformation in the process of dynamic recrystallization， AZ91-of-cast thick dendrite become equiaxed， when the deformation temperature rise and increase the degree of deformation to a certain extent， re-crystallization of the basic completely, and uniform distribution of grain Significantly refined. As the total grain grown up around the interface can be poor， pressure riveting distortion temperature is too high would cause recrystallization be no distortion of the axis， such as fine-grained continue to grow into a uniform distribution of coarse grains.
In short， the study showed that， 600 ℃ under pressure riveting experiment by the joint best quality magnesium alloy， this temperature can be riveting as the practical application of technology needed for the reference temperature.


Key words：Magnesium alloy AZ91，Riveting，Deformation，Organization




目 录

中文摘要 Ⅰ
ABSTRACT Ⅱ
1绪论 1
1.1 镁及镁合金简介 1
1.1.1镁及镁合金的特点 1
1.1.2 镁合金的分类及表示方法 2
1.1.3镁合金的应用现状和发展前景 4
1.2 镁合金与异种材料之间的连接技术 5
1.2.1 激光胶接焊 5
1.2.2钎焊 6
1.2.3粘接 8
1.2.4机械紧固 10
1.3 本课题的目的及研究意义 11
2 新型铆接技术的基本原理 13
2.1新型镁合金铆接技术 13
2.2镁合金铆接变形特点 16
3 实验过程 17
3.1实验目的 17
3.2实验内容及步骤 17
3.2.1实验器材 17
3.2.2实验步骤 17
4 实验结果与分析 21
4.1实验结果 21
4.2实验分析 27
5 结论 31
致谢 32
参考文献 33