摘 要

鎂合金由于其優(yōu)異的性能而成為備受關(guān)注的新型材料。鎂合金件在應用中難免會與其它材料的零部件連接，由于鎂合金具有特殊的材料及腐蝕特性，其與異種材料結(jié)構(gòu)件之間的連接技術(shù)成為制約鎂合金廣泛應用的障礙之一。近些年, 雖然也有人研究用焊接、釬焊或膠接等方法進行鎂合金與異種材料的連接問題，但鉚接技術(shù)由于其簡單可靠、工藝成本低等優(yōu)點仍是解決鎂合金與異種材料連接的重要手段之一。
本研究主要針對鎂合金發(fā)動機罩蓋開發(fā)過程中遇到的壓鑄罩蓋體與鋼制板狀零件的連接問題，開發(fā)了具有自鉚特征的熱壓鉚新技術(shù)，本文重點開展了不同溫度（500 oC、600 oC和700oC）下對鎂合金零件的壓鉚實驗，然后對比不同實驗參數(shù)下的壓鉚接頭組織進行了分析。實驗結(jié)果表明：隨著壓鉚溫度的升高，鎂合金AZ91更易發(fā)生塑性變形，更易形成壓鉚接頭。在壓鉚變形過程中出現(xiàn)動態(tài)再結(jié)晶，AZ91基體的鑄態(tài)粗大樹枝晶變成等軸晶，當變形溫度升高和變形程度加大到一定程度，再結(jié)晶基本完全，晶粒分布均勻并得到顯著細化。由于晶粒長大前后總的界面能差，壓鉚變形溫度太高則會造成再結(jié)晶得到的無畸變等軸細晶粒繼續(xù)長大變成均勻分布的粗晶粒。
總之，上述研究表明，600℃下進行壓鉚實驗得到的鎂合金接頭質(zhì)量最好，可以將此溫度作為該鉚接技術(shù)實際應用時所需溫度的參考。


關(guān)鍵詞：AZ91鎂合金，鉚接，變形，組織












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 錄

中文摘要 Ⅰ
ABSTRACT Ⅱ
1緒論 1
1.1 鎂及鎂合金簡介 1
1.1.1鎂及鎂合金的特點 1
1.1.2 鎂合金的分類及表示方法 2
1.1.3鎂合金的應用現(xiàn)狀和發(fā)展前景 4
1.2 鎂合金與異種材料之間的連接技術(shù) 5
1.2.1 激光膠接焊 5
1.2.2釬焊 6
1.2.3粘接 8
1.2.4機械緊固 10
1.3 本課題的目的及研究意義 11
2 新型鉚接技術(shù)的基本原理 13
2.1新型鎂合金鉚接技術(shù) 13
2.2鎂合金鉚接變形特點 16
3 實驗過程 17
3.1實驗目的 17
3.2實驗內(nèi)容及步驟 17
3.2.1實驗器材 17
3.2.2實驗步驟 17
4 實驗結(jié)果與分析 21
4.1實驗結(jié)果 21
4.2實驗分析 27
5 結(jié)論 31
致謝 32
參考文獻 33