摘要本文综述了高强铝合金双轴肩搅拌摩擦焊接工艺的研究，从材料选择和结构两方面设计了两种双轴肩搅拌头，并设计了与双轴肩搅拌头相适应的夹具。从搅拌头转速、焊速、母材预热时间等方面设定工艺参数，进行双轴肩与单轴肩搅拌摩擦焊接实验。并分析了双轴肩搅拌摩擦焊与单轴肩搅拌摩擦焊所获得的焊接接头的宏观形貌、微观组织、显微硬度等接头性能。结果表明，搅拌头转速过高以及焊速调节过快，都会使搅拌头断裂。不论是单轴肩还是双轴肩，焊缝的焊核区的组织都是明显均匀细小等轴晶粒，而热机影响区则会出现晶粒粗化现象。双轴肩搅拌摩擦焊焊缝上的显微硬度分布大致呈高-低-高-低-高的趋势。双轴肩FSW焊缝上下表面的硬度差异要比单轴肩FSW的要小。23913
关键词 双轴肩搅拌摩擦焊 双轴肩搅拌头 7A52铝合金 焊接夹具 微观组织
毕业设计说明书（毕业论文）外文摘要
Title The studys on bobbin tool friction stir welding of high-strength aluminum alloy
Abstract
This article aims at studying bobbin tool friction stir welding process of high-strength aluminum alloy 7A52. Designing two kinds of biaxial shoulder mixing head from material selection and structure.Also we designed the welding fixture according to biaxial shoulder mixing head. Performing experiments on bobbin tool FSW and traditional FSW by setting process parameters such as stirring speed and welding speed, the parent metal preheating time. Analyzing the macromorphology, microstructure, microhardness and other joint performance of BTFSW and FSW.The results showed that the mixing head high rotation speed and fast welding speed regulating can make mixing head fracture.Both single shaft shoulder and biaxial shoulder, NZ has obvious even small equiaxed grain, and the HAZ has grain coarsening phenomenon .Biaxial shoulder friction stir weld on the microhardness distribution has roughly high - low - high - low - high trend.Biaxial shoulder FSW weld hardness difference of top and bottom surface is smaller than single shaft shoulder FSW.
Keywords bobbin tool friction stir welding biaxial shoulder mixing head 7A52 welding fixture microstructure phase
目次
1 引言 1
1.2 搅拌摩擦焊的研究 1
1.3 双轴肩搅拌摩擦焊的研究 3
1.4 高强铝合金的焊接性 3
1.5 搅拌头的研究 4
1.6 高强铝合金搅拌摩擦焊国内外研究现状 7
1.7 课题研究内容及方法 7
2 实验材料及设备 10
2.1 实验设备 10
2.2 实验材料 12
3 搅拌头设计 13
3.1 搅拌头材料的选择 13
3.2搅拌头承载分析 14
3.3 搅拌头结构设计 15
3.4 本章小结 17
4 辅助工具设计 18
4.1 夹具 18
4.2 加热装置 19
4.3 本章小结 20
5 双轴肩搅拌摩擦焊接工艺研究 21
5.1 实验工艺方案 21
5.2 双轴肩搅拌摩擦焊焊缝宏观形貌观察 21
5.3 单轴肩搅拌摩擦焊焊缝宏观形貌观察 25
5.4 本章小结 26
6 焊接接头微观组织及力学性能分析 28
6.1 双轴肩搅拌头的焊缝分析 28
6.2 单轴肩搅拌头的焊缝分析 30
6.3 本章小结 32 高强铝合金双轴肩搅拌摩擦焊接研究:http://www.751com.cn/cailiao/lunwen_17169.html