钛合金激光+PMIG对接焊工艺与过程保护试验研究
摘要本论文采用光纤激光+PMIG复合热源焊接方法，开展了板厚3mm的TC4钛合金焊接工艺、成型、组织性能等研究。研究表明：钛合金采用激光+PMIG复合热源焊方法，在改善焊缝表面缺陷上优势明显，能得到外观呈光亮色泽，飞溅、氧化等焊接缺陷少的焊缝。并对其焊接过程中气体保护工作做出了探究。通过微观分析和力学性能测试，得到其抗拉强度能达到母材96％以上，硬度由焊缝向母材依次降低。相比传统MIG焊接、激光焊接，复合热源焊在提高接头性能方面展现很大优势。而通过不断改变电弧电流I、激光功率参数P，并对系列焊接接头对比，进行参数优化。其中激光功率和电弧电流对焊缝正、背面宽度影响较大。根据焊接的板厚确定所需的激光功率和电弧电流。68278
毕业论文关键词： TC4钛合金 光纤激光+PMIG复合热源焊接 参数优化微观组织 接头力学性能
毕 业 论 文 外 文 摘 要
Title TC4 titanium alloy laser + PMIG welding process experimental study and process protection
Abstract
Using the optical fiber laser welding + PMIG composite heat source method, The thickness of 3 mm TC4titanium alloy welding, molding and organization performance are Carried out. Research shows that: Titanium alloy laser welding + PMIG composite heat source method. have advantages in improving the weld surface defects. Can get appearance bright color, less spatter and weld defects such as oxidation of welds. And the gas protection welding process has made the exploration. By microscopic analysis and mechanical property test，Its tensile strength can reach the parent metal of more than 96%，From the weld to the parent metal hardness reduced in turn，Compared to conventional MIG welding, laser welding，Composite heat welding show great advantages in terms of improving joint performance. And through continuous change of arc current and the parameters of the laser power P, I and the series of welding joint, parameters optimization. The laser power and arc current to weld, the back width influence. According to the welding of thickness to determine the required laser power and the arc current.
Keywords: TC4 Titanium Alloy Fiber Laser + Pulse MIG Welding Parameter optimization Microstructure
Joint mechanical properties
目 次
第一章 绪论 1
1.1 选题背景及意义 1
1.3 TC4钛合金焊接性能分析 3
1.3.1 高温时钛合金高活性 3
1.3.2 钛合金焊接接头脆化和裂纹倾向 4
1.3.3 钛合金焊接气孔问题 4
1.4 激光+PMIG 复合热源焊接的优点 4
1.5 激光+PMIG电弧焊的研究 6
1.5.1 激光+PMIG复合热源焊接的作用机理 6
1.5.2 激光+PMIG复合热源焊接的作用方式 6
1.5.3 激光+PMIG复合热源焊接影响参数 8
1.6 课题研究的主要内容