摘要搅拌摩擦焊（FSW)是一种新型的固相连接技术，多用于接头的对接，主要是铝 合金、镁合金的焊接。目前，搅拌摩擦焊广泛应用于轨道交通、船舶、航空航天等 领域。但大都是利用搅拌摩擦焊对铝合金厚板进行焊接，对于铝合金薄板的焊接还 没有像厚板焊接那么应用广泛。80925

本文主要研究 1 mm 厚的 2014 铝合金薄板的搅拌摩擦，本实验的难点在于：① 被焊材料很薄，很难对其焊接，形成完整的焊接接头。②焊接完成后工件变形比较 大。③焊缝很容易出现减薄的现象。采用高压水冷装置和合理的焊接工艺参数能有 效地解决上述问题。

本实验的内容是：在高压水冷条件下，采用合理的焊接工艺参数对薄板进行焊 接，并形成良好接头；探索焊缝的宏观形貌和微观组织变化；通过拉伸强度的测量 和硬度值的测量来分析焊接接头的力学性能：综合分析后找出最佳的焊接工艺参数。

毕业论文关键词:铝合金； 搅拌摩擦焊；力学性能；焊接工艺参数；微观组织；宏观形貌

AbstractFriction stir welding (FSW) is a new type of solid state connection technology, which is mainly used in the welding of aluminum alloy and magnesium alloy。 At present, friction stir welding is widely used in the field of rail transport, ship, aerospace and other fields。 But most of the aluminum alloy thick plates are welded by friction stir welding, and the welding of aluminum alloy sheet is not as wide as that of thick plate welding。

This paper mainly studies the FSW of the 1mm thick 2014 aluminum alloy sheets, which has a lot of difficult lies。 First, The material is very thin, it is difficult to be welded ang form a complete welding joint。 Moreover, The workpiece deformation is relatively larger after welding。The last but not least, the thickness of weld seams will reduce。 The above problems can be effectively solved by using high pressure water cooling device and reasonable welding parameters。

This experiment has some contents。 First, The thin plates are welded by using high pressure water cooling device and reasonable welding parameters, and a good joint is formed。 Second, the macro morphology and microstructure changes of the weld were explored。 Third, The mechanical properties of welded joint were analyzed by the measurement of the tensile strength and the hardness value。 The last, the best welding parameters were found out, after comprehensive analysis。

Key words: Aluminum alloy; Friction stir welding; Mechanical properties; Welding parameters; Microstructure; Macro morphology

第一章 绪 论 1

1。1 前言 1

1。2 搅拌摩擦焊综述 1

1。2。1 常规搅拌摩擦焊的原理 1

1。2。2 搅拌摩擦焊的特征 2

1。2。3 搅拌摩擦焊的应用 3

1。3 搅拌摩擦焊的研究现状 5

1。4 研究内容及方法 7

1。4。1 研究内容 7

1。4。2 研究方法 7

第二章 试验材料设备和方案 8

2。1 试验材料 8

2。2 实验设备 8

2。2。1 搅拌摩擦焊焊机的介绍 8

2。2。2 搅拌头的设计 9

2。2。3 冷却装置 10

2。3 焊接试验过程及其影响因素