摘要本课题研究材料为 6061铝合金与AZ31B镁合金，使用机器人MIG焊对镁、铝异种合金的焊接性进行了试验研究。试验综合考虑I型接头留与不留缝隙，焊枪偏置与不偏置进行了焊接参数试验研究，得到了质量良好的接头。在此基础上对焊接接头进行了X射线探伤，分析了焊缝中常见缺陷纵向裂纹和气孔的产生原因。试样拉伸试验断裂发生在近镁一侧，抗拉强度为2。83Mpa。断口SEM扫描确认断裂方式为脆性断裂。显微硬度测试表明镁侧熔合区硬度比其他部分高出较多。以上三个试验确认了金属间化合物生成并在镁一侧量较多，其存在影响了焊接接头的性能。金相分析显示镁侧熔合区很宽，靠焊缝一侧有柱状晶，热影响区存在一定量的过烧组织，两者降低了焊接接头性能。87851

毕业论文关键词  镁铝异种合金焊接  熔焊  MIG焊  金属间化合物

毕业设计说明书外文摘要

Title  Study On Robot Welding Process Of Thin Plate Light Alloys

Abstract This study based on 6061 aluminum alloy AZ31B magnesium alloy, using robot MIG welding process to research the weldability between dissimilar alloy Mg and Al。 

The experiment took whether leaving a gap in type I joins, welding torch offset or not and welding parameters into consideration, and finally obtained a fine join。 On the base of this, using the X-ray radiographic inspection to detect defects, then analyzed the cause of formation of the most common defects: longitudinal crack and pore。 The break occurred on the magnesium side of the specimen in the tensile test, and the tensile strength was 2。83Mpa。 SEM scan of the fracture confirmed the fracture mode was brittle fracture。 Micro hardness test showed that the hardness of the magnesium side fusion zone was higher than that of the other parts。 The three experiments above confirmed the formation of intermetallic compounds and its amount in magnesium side was more than other parts, its presence affected the performance of welded joints。 The metallographic analysis showed that the magnesium side fusion zone is very wide and there is a columnar grain on one side of the weld。 The heat affected zone exists overheat microstructures。 Both columnar grain and overheat microstructures degraded the performance of welded joints

Keywords  Welding Of Dissimilar Alloys Magnesium And Aluminum  Fusion Welding     MIG  Intermetallic Compound

目   次

1  引言 1源-于,优Y尔E论W文.网wwW.yOueRw.com 原文+QQ752018`766

1。1  课题意义 1

1。2  镁、铝及其合金的性能和应用 1

1。2。1  铝及铝合金的性质和应用 2

1。2。2镁及镁合金的性质和应用 2

1。3   镁、铝异种金属焊接特点 3

1。4   镁、铝异种金属焊接现状 4

1。4。1  镁、铝的熔焊 4

1。4。2  镁、铝的钎焊 5

1。4。3  镁、铝的固相焊 6

2  试验材料及方法 8

2。1  试验材料 8

2。2  机器人MIG焊系统 8

2。3  试验方法与流程 10

2。3。1  试验流程 10

2。3。2  试验具体方法