摘要铜铝是优良的导电材料，广泛地应用于电力电子工业。与铜相比，铝具有质量轻、价格低的优点，在某些场合利用铝代替铜的使用，不仅可以降低成本，而且可以降低工程结构的重量。然而铝铜密度、熔点、热导率等物理性能相差大，传统熔焊方法难于实现较好的连接。作为新型固相连接技术的搅拌摩擦焊已被广泛应用于异种金属的连接。78227

本文对6mm的1060铝和2mm的T2铜进行搅拌摩擦焊搭接试验，形成铝-铜以及铜-铝-铜搭接接头。调整工艺参数以改变热输入，分析工艺参数对焊缝表面成形、过渡层微观组织的影响，分析铝铜异种金属搅拌摩擦焊微观组织以及剪切断口的特点，为工艺优化提供理论依据。

研究结果表明：铝铜异种金属搅拌摩擦焊可以获得优良的搭接接头，当旋转速度n=1100rpm、焊接速度v=60mm/min时，焊缝表面成形较好。轴肩部位铜铝界面处形成一定范围的过渡层，组织形态随热输入改变而发生变化。焊核区内显微硬度可达500HV，接头剪切强度随工艺参数变化不大。在三层搭接接头，上层铝铜接头对下层铝铜接头的组织结构、显微硬度、剪切强度产生一定的影响。

毕业论文关键词： 搅拌摩擦焊；铝铜异种金属；搭接；微观特征

Abstract Copper and aluminum are both excellent conductive material, which are widely used in power electronic industries。 Compared with copper, aluminum can be used in some areas instead of copper with its advantages of light weight and low-cost so that reduces the costs as well as the weight of engineering structures。 However, the physical properties such as density, melting point and thermal conductivity of aluminum and copper are largely different, so fine joints are hardly achieved by traditional welding methods。 Friction stir welding as a new solid phase connection technology has been widely used to connect dissimilar metals。

In this paper, 6mm thick 1060A pure aluminum plate and 2mm thick T2 copper plate were connected by friction stir welding so aluminum-copper and copper-aluminum-copper lap joints were formed。 The influence of process parameters which were adjusted in order to change the heat input on the weld surface morphology and microstructure of transition were investigated。 Also, the characteristics of aluminum-copper dissimilar metal FSW microstructure and shear fracture were analyzed, so as to provide a theoretical basis for process optimization。

The results show that a well aluminum-copper dissimilar metal FSW lap joint can be achieved when the rotational speed is 1100rpm, the welding speed is 60mm / min, preferably forming weld surface。 The weld nugget zone hardness is up to 500HV and joint shear strength hardly change with the persification of process parameters。 In the three-lap joint, the upper aluminum-copper joints have a certain impact on the organizational structure, hardness, shear strength of the underlying aluminum-copper joints。

Keywords: Friction Stir Welding;  Aluminum-Copper Dissimilar Metal; Lap Joints; Microscopic Features

目录

第一章  绪论 1

1。1 选题背景 1

1。2 异种金属的焊接 2

1。2。1 异种材料的焊接性 2

1。2。2 铝铜异种材料的焊接性 3

1。2。3 异种金属的搅拌摩擦焊 4

1。3 本课题国内、外研究现状与发展趋势 6

1。3。1 铝-铜异种材料的搅拌摩擦焊国外研究现状 6

1。3。2 铝-铜异种材料的搅拌摩擦焊国内研究现状