铝合金激光焊接工艺特性研究

结合近年铝合金激光焊接的研究情况,阐述了铝合金激光焊接与复合焊接的特点以及研究现状,分析了铝合金的焊接特性以及焊接工艺参数对焊接质量的影响,讨论了激光焊接时存在的问题和解决措施。     

铝合金激光焊接技术研究进展

综述铝合金激光焊接技术特点及研究现状,开展3 mm厚LF6铝合金激光-MIG电弧复合焊接工艺研究。文献综述表明,铝合金激光自熔焊接表面成形不好,且易于产生气孔缺陷,激光填丝焊、激光-电弧复合焊以及双光束激光焊等能够有效地解决上述铝合金激光焊接问题。试验研究表明,激光-MIG电弧复合焊接LF6铝合金可获得良好的焊缝成形,内部质量达到QJ1666A-2011Ⅰ级焊缝质量要求,接头强度达到母材的90%以上,具备较为优异的力学性能。     

铝合金激光焊接技术特性

主要综述了铝合金激光焊的焊接特性，如小孔效应及等离子问题，讨论了焊接工艺参数对焊接质量的影响，分析了影响焊缝质量的因素(气孔、裂纹等)，同时提出了改进措施，并介绍了铝合金激光焊接的几种新方法。     

高强铝合金双焦点激光焊接研究现状

高强铝合金在激光焊接时,易出现气孔、热裂纹、焊接接头性能差、厚板与不等厚板难以焊接、熔池温度场与流场变化难以测量等问题,严重限制着高强铝合金的发展。目前,双焦点激光焊接技术能够有效地改善高强铝合金激光焊接中出现的问题。本文简要介绍了双焦点激光焊接的原理及实现方式,探究双焦点激光焊接对上述高强铝合金激光焊接中出现的问题的影响。     

光纤激光器在铝及铝合金焊接中的应用

介绍了铝及铝合金激光焊接特性,对光纤激光器的原理和优势做了简介。对铝及铝合金激光焊接工艺参数对焊接质量的影响进行了分析。举例说明了光纤激光器在铝及铝合金焊接中应用,并对光纤激光器焊接应用进行了展望。     

6061铝合金光纤激光填丝焊工艺与性能研究

采用光纤激光填丝焊工艺对6061铝合金进行焊接,研究了激光功率、焊接速度和送丝速度对铝合金激光焊接接头质量和热输入对接头拉伸性能的影响。结果表明,6061铝合金激光填丝最佳焊接工艺为激光功率2 k W、焊接速度3 m/min、送丝速度1.5~3.0 m/min。激光焊接接头抗拉强度随热输入增加而降低,热输入由80 J/mm增加到146J/mm,抗拉强度由218 MPa降低到206 MPa。     

激光-MIG复合焊工艺及其在轨道交通领域应用现状

阐述了激光-MIG复合焊接的基本原理和特点;介绍了铝合金激光-MIG复合焊接的工艺特性、研究现状及其在轨道交通车辆行业的工业应用。激光-MIG复合焊接充分集成激光焊接与MIG焊接的优点,能有效解决铝合金焊接的诸多问题,在轨道交通领域将会得到更加广泛的应用。     

航空铝合金激光焊接的研究进展

铝合金在航空领域的应用越来越广泛,而激光焊接以其特有的技术优势成为铝合金材料焊接的重要方法,在航空领域有着广阔的应用前景。介绍了目前铝合金激光焊接中的主要问题以及国内外的研究热点。     

激光-MIC复合焊工艺及其在轨道交通领域应用现状

阐述了激光-MIG复合焊接的基本原理和特点;介绍了铝合金激光-MIG复合焊接的工艺特性、研究现状及其在轨道交通车辆行业的工业应用.激光-MIG复合焊接充分集成激光焊接与MIG焊接的优点,能有效解决铝合金焊接的诸多问题,在轨道交通领域将会得到更加广泛的应用.     

建筑电气设备铝合金壳体的焊接技术

铝合金具有较高的热导率,导致焊接时热量迅速传递给周围材料,容易造成熔池飞溅、产生裂纹等,影响焊接效果,为此,文中提出采用激光焊技术对建筑电气设备铝合金壳体实施焊接,并从焊接接点部署、焊接拉伸角度、激光入射角度等方面计算焊接最佳参数;引入锤击法完成铝合金壳体的锻延,增加焊接处关联密度,提高整体焊接质量。试验结果表明,利用这种方法对建筑电气设备铝合金壳体展开焊接,能够有效避免焊接飞溅、裂纹等的产生,整体焊接质量较高。     

Pore formation during continuous wave Nd:YAG laser welding of aluminium for automotive applications

Summary

Pore formation is an important concern in laser welding of automotive aluminium alloys. This paper investigates the influence of laser beam defocus on pore formation during continuous wave Nd:YAG laser welding of 5182 and 5754 automotive aluminium alloys. It was found that the instability of the keyhole during welding was a dominant cause of pore formation while hydrogen rejection played an insignificant role. The defocusing of the laser beam greatly affected the stability of the keyhole. Finally, the mechanism of keyhole collapse and pore formation is proposed.     

Welding phenomena and in-process monitoring in high-power YAG laser welding of aluminium alloy

Laser welding of aluminium alloys is difficult because of their low laser coupling, easy formation of welding defects, etc. and thus the establishment of in process monitoring technique is expected in various industries to obtain highly reliable laser welds. In this study, therefore, both the reflected laser beam and radiation light from die molten pool were investigated as monitoring signals during YAG laser welding of A5052 and A5182 aluminium alloy to confirm validity and usefulness of these signals for monitoring. At the same time, laser-welding phenomena were observed through a high-speed video camera to better interpret the monitored signals. Two signals were detected by utilizing photo sensors and band pass or cut-off filters coaxially against a laser beam and from the above-back direction. In this paper, experimental setup, and monitoring and observation results were presented. The correlation between monitoring signals and welding phenomena was clarified when the welding defects such as underfilling and through holes were formed.     

Laser beam welding of wrought aluminium alloys

Abstract

Laser beam welding is now a common manufacturing method for a wide range of steel products from automobiles to razor blades. However, the process has only recently been approved for critical applications involving aluminium alloys, notably in the aerospace and automotive industries. The properties of aluminium alloys influence the interaction between the beam and the material to a far greater extent than for steels. The challenge of developing industrial welding procedures has therefore been considerable. The present review describes the effects of CO₂ and Nd–YAG laser beam processing parameters and the properties of the most common wrought aluminium alloys on the characteristics of welded joints. Porosity, solidification cracking, and poor weld bead geometry are shown to be the most frequently encountered imperfections. These can be eliminated through the use of appropriate filler materials, process gases, material preparation, and in some instances, adaptive control systems. Very little work has been reported on the corrosion properties of laser welded aluminium alloys. Experimental processing parameters are presented and compared using an analytical model, which can also be employed for predictive purposes. A number of industrial applications are described. These demonstrate that, for specific alloys, the process is now sufficiently well understood to be approved for high volume production, particularly in the transport industries.     

Hybrid laser-arc welding of aluminium alloys

Special features of laser welding of aluminium alloys with laser and arc heat sources are investigated. Advantages and shortcomings of these methods are noted. Experiments were carried out to combine laser and arc heat sources for welding aluminium alloys. Equipment for hybrid welding is described. The technological parameters influencing the external formation of the welded joints are determined. Specific conditions for welding 1424 aluminium alloys with a thickness of 4.0 mm are presented. High-quality welded joints were produced by hybrid laser-arc welding in 1424 alloy with a thickness of 4.0 mm.     

铝合金激光焊接的工艺特性及其发展现状

概述了铝合金激光焊接的工艺特性及难点，指出了铝合金激光焊接技术的研究现状及发展方向。     

铝/钛异种合金激光深熔钎焊试验分析

采用3500W板条式扩散冷却CO2激光器,利用激光深熔钎焊原理对3mm厚6061铝合金和钛合金进行异种金属激光焊接.聚焦激光作用在铝合金一侧为深熔焊,熔化的铝合金浸润钛合金界面形成钎焊接头.拉伸试验发现,断裂均发生在界面处,通过Olympus金相显微镜观察发现断口存在部分未熔合.结果表明,降低焊接速度,并采用合适的偏焦量,负离焦量和偏转角度可以改善界面的熔合.     

几种常见合金的激光扫描焊接特性及研究现状

激光扫描焊接是一种高效的新型激光焊接技术,具有独特的激光束定位方式、扫描范围广、灵活性高、工作距离长等优点,相比于传统激光焊接,其多点焊接的特性能在很大程度上提升焊接效率.概述了激光扫描焊接技术的工作原理和分类,重点阐述铝合金、镁合金、钛合金、铜及铜合金、铝-钢异质合金几种常用合金的激光扫描焊接特性及研究现状.扫描激光...     

空心铝球的电子束焊接

铝合金的可焊接性较差,熔焊时易产生裂纹和气孔等缺陷,理论分析了缺陷产生的原因.真空电子束焊接独特的优点可以解决铝合金的焊接难题.空心铝球的焊接更有特殊性,采用真空电子束焊接比激光焊接更为有利.主要探讨了工件的精度、清洁处理、工装夹具、焊接范等因素对焊接质量的影响,并分析了焊接结果.     

Effects of magnesium content on dual beam Nd : YAG laser welding of Al – Mg alloys

Abstract

The effects of Mg content on the weldability of aluminium alloy sheet using the dual-beam Nd:YAG laser welding process have been studied by making bead-on-plate welds on 1.6 mm thick AA 1100, AA 5754 (3.2 wt-%Mg) and AA 5182 (4.6 wt-%Mg) alloy sheets. Whereas all full-penetration laser welds made in 1100 aluminium were of excellent quality,many of the welds produced in the aluminium–magnesium alloys exhibited rough, spiky underbead surfaces with drop-through and undercut. A limited range of process variables was found, however, that allowed welds with acceptable weld bead quality to be produced in the 5754 and the 5182 alloy sheet. Goodwelds were only produced in these alloys if the lead/lag laser beam power ratio was ≥1. Weld penetration and the maximum welding speed allowing full penetration keyhole-mode welding were observed to increase with Mg content. This was attributed to the effect of Mg on the vapour pressure within the keyhole and the surface tension of the Al–Mg alloys. Significant occluded vapour porosity was seen in the 5754 and 5182 alloy welds with borderline penetration; however, there was no evidence of porosity in the acceptable full-penetration welds with smooth underbead surfaces. Hardness profiles in the 5754 and 5182 welds showed a gradual increase in hardness from the base metal values through the heat affected zone (HAZ) to a peak in hardness in the weld metal adjacent the fusion boundary. It is possible that this increase in hardness may be the result of the presence of Mg₂Al₃ or metastable Mg₂Al₃′ precipitates in this region of the weld and HAZ.