摘要：本文设计了一种高转速搅拌摩擦焊具，焊具机械部分由机械本体、高转速搅拌摩擦头、电机组成，控制部分由控制系统、测控系统组成，焊接转速可高达15000rpm，主要针对1mm及以下薄壁铝镁铜等轻合金焊接，具有焊接变形小、效率高、焊缝成型好等优点。并对1mm3003-H32薄壁铝合金进行了高转速搅拌摩擦焊接工艺试验，研究了合理的焊接工艺参数范围，利用光学显微镜、维氏硬度计和万能拉伸试验机对其微观组织和力学性能进行了分析。研究表明：当焊接转速达到10000rpm以上时，可以实现1mm3003-H32铝合金的对接，焊缝成型美观，焊核区晶粒细小而均匀，有较好的焊接接头质量。当主轴转速一定时，随着焊接速度的增加，接头抗拉强度出现先增大后减小的变化；焊接速度一定时，随着主轴转速的增加，抗拉强度也呈现先增大后减小的趋势。主轴转速在11000rpm、焊接速度1000mm/min时，接头抗拉强度最高，达到母材的78%，前进侧硬度值稍高于后退侧，焊缝区硬度值为28HV,约为母材的58.3%。

关键字：高转速；搅拌摩擦焊；组织与性能；轻合金焊接

Abstract：This paper designs a kind of high speed friction stir welding tool. The welding tool is composed of mechanical body, high speed stirring friction head, motor drive and its control system, measurement and control system. The welding speed can be as high as 15000rpm, mainly for 1mm and below thin-walled aluminum Magnesium and other light alloy welding, with a small welding deformation, high efficiency, good welds and other advantages. The welding process of 1mm3003-H32 thin-walled aluminum alloy was studied by means of high speed friction stir welding process. The reasonable range of welding parameters was studied. The microstructures and mechanical properties were analyzed by metallographic microscope, Vickers hardness tester and universal tensile tester. The results show that when the welding speed reaches 10000rpm or more, the 1mm3003-H32 aluminum alloy can be docked, the weld shape is beautiful, the grain size of the welding nucleus is small and uniform, and the quality of the welded joint is better. When the speed of the spindle is constant, the tensile strength of the joint increases first and then decreases with the increase of the welding speed. When the welding speed is constant, the tensile strength increases first and then decreases with the increase of the spindle speed. When the spindle speed is 11000rpm and the welding speed is 1000mm/min, the tensile strength of the joint is the highest, reaching 78% of the base metal. The hardness value of the advancing side is slightly higher than the retreating side, the hardness of the weld zone is 28HV, about 58.3% of the base metal.

Keywords：High speed；Friction stir welding；Oganization and performance；Light alloy welding

目 录

第一章 绪论 1

1.1选题背景及意义 1

1.2搅拌摩擦焊 2

1.2.1搅拌摩擦焊原理 2

1.2.2搅拌摩擦焊特点 2

1.2.3搅拌摩擦焊的研究现状 3

1.3高转速搅拌摩擦焊 4

1.3.1高转速搅拌摩擦焊原理 4

1.3.2高转速搅拌摩擦焊特点 4

1.3.3薄板铝合金搅拌摩擦焊的研究现状及问题 4

1.4研究内容与目的 6

1.4.1研究内容 6

1.4.2研究目的