钢/铝异种金属连接工艺的研究现状

近年来采用钢与铝异种金属连接结构的产品越来越多,采用钢铝异种金属焊接可以减轻结构部件的重量,实现轻量化。但钢铝焊接时易出现裂纹、金属间化合物等,严重影响了焊接接头质量。笔者阐述了近年来国内外钢铝异种金属之间各种焊接工艺（压焊、钎焊、熔焊、搅拌摩擦焊）的研究现状,认为激光熔-钎焊方法既易于控制焊接热输入,又能较好的控制钢铝金属间脆性物质层,是一种实现钢与铝异种金属连接的具有前景的工艺。     

钢铝异种金属连接方法现状分析

由于单一金属材料性能的局限性,比如单一金属本身不具备应用所需的所有物理、化学和机械方面的性能,而异种金属接头可以满足需求,这就使得钢铝异种金属的连接变得越来越重要,另外使用钢铝异种金属连接还可以节省费用、节约能源.详细介绍了激光熔焊-钎焊法、脉冲熔焊-钎焊法和CMT法三种连接钢铝异种接头的新型电弧熔焊-钎焊法,这些方法在钢一侧为钎焊,在铝一侧为熔焊,热输入低,熔池温度梯度高,冷却速度快,大大降低了钢铝接头中金属间化合物层的厚度,可以获得良好的接头性能,具有广泛的应用前景.     

铝与钢异种金属电弧熔-钎焊研究与发展现状

铝与钢的连接已成为焊接领域中的热点和难点问题,电弧熔-钎焊在铝与钢异种金属连接中受到了越来越广泛的重视和研究.文中详细分析了铝与钢异种金属的焊接性,金属间化合物层的存在是影响接头性能的关键因素,重点阐述了电弧熔-钎焊的工艺特点和钢表面镀层工艺的研究,电弧熔-钎焊过程兼备熔焊和钎焊的双重特点,铝侧为熔焊结合,钢侧为钎焊结合,指出了镀层工艺存在的问题,综述了铝与钢电弧熔-钎焊国内外最新研究进展,并对铝与钢电弧熔-钎焊的研究方向进行了预测.     

钢铝异种金属新型电弧连接法研究现状

介绍了3种连接钢铝异种接头的新型电弧熔焊一钎焊法，这些方法在钢一侧为钎焊，在铝一侧为熔焊，热输入低，熔池温度梯度高，冷却速度快，大大降低了钢铝接头中金属间化合物层的厚度，可以获得良好的接头性能。     

钒合金与钢异种材料焊接研究现状分析

以钎焊、压焊和熔焊为研究主体,综述了钒合金与钢的连接技术研究进展.现有的研究成果表明,钒合金与钢的连接存在着很大的难度,材料表面氧化膜、结合界面形成的脆性金属间化合物是影响接头性能的关键.解决的有效途径是:选择合适的中间层材料,如Au-Ni,V,Nb等,可以很好地润湿钒合金与钢以提高接头性能;采用爆炸焊或摩擦焊的固相连接手段,避免金属的熔化;采用熔化低熔点金属润湿-钎接高熔点金属的方法精确控制材料之间的反应,将产生金属间化合物的可能性降至最低,以实现异种金属间的可靠连接.     

铝/钢异种金属焊接技术的研究现状

工程装备轻量化及对工程结构安全性的需求,使得铝/钢异种金属的连接构件在工程装备制造领域具有广阔的应用前景,然而铝/钢物理冶金及化学性能的巨大差异使其连接的可靠性成为影响构件安全运行的关键。文中综述了铝/钢异种金属焊接技术的研究进展,主要介绍了铝/钢熔焊、钎焊和压焊、复合焊的研究现状。针对目前各种焊接技术急需解决的问题以及铝/钢合金焊接的发展方向,总结出了今后铝/钢合金焊接研究的重点内容,并对铝/钢合金焊接前景进行了分析与展望。     

钛／铝异种轻金属熔焊技术的研究进展

近年来钛／铝异种轻金属复合结构在航空航天领域的应用受到越来越多的关注。但由于钛／铝之间物化性能相差较大,在进行熔焊连接时易出现裂纹、焊接变形较大、易生成脆性金属间化合物,导致接头较难实现可靠连接。文中针对钛／铝异种轻金属熔焊难点,阐述了国内外对钛／铝异种轻金属之间熔焊技术（激光熔钎焊、电子束焊、钨极氩弧焊）的研究进展,针对各种熔焊技术中存在的不足,讨论了钛／铝异种金属熔焊工艺的改进措施。     

铝-钢连接液固界面反应研究进展

详细综述了铝钢异种材料连接过程中液态铝与固态钢界面反应的研究进展,重点分析了钢的热浸镀铝、铝钢异种金属钎焊以及熔钎焊的界面反应产物的种类、生成顺序及生长机制,并对熔钎焊短时非平衡态固液界面反应的特点进行了分析和讨论。     

送丝速度对铝/钢激光填丝熔钎焊性能的影响

采用光纤激光器对铝/钢异种金属搭接接头进行激光填丝熔钎焊试验研究。分析了送丝速度对焊缝成形质量、金属间化合物层厚度及力学性能的影响。试验结果表明,选择适当的送丝速度,利用铝和钢的不同熔点,使铝母材刚好熔化但是钢母材不熔化,熔化的铝母材与填充金属一起铺展在钢母材表面并与其实现钎焊连接,可形成优质的熔钎焊接头。当送丝速度小于3. 5 m/min时,易形成硬脆性金属间化合物而导致焊缝开裂。金属间化合物层厚度应控制在一定范围内,方可保证接头性能。当送丝速度为4. 5 m/min时,焊接接头强度有所提高,其线载荷达到203. 5 N/mm,约为铝合金母材抗拉强度的83. 7%。     

铝/铜异种材料的焊接研究

由铝/铜异种材料组成的复合结构在电力工业具有广阔的应用前景,深入研究铝/铜的焊接方法及工艺是很有必要的.文中从熔焊、压焊、钎焊以及搅拌摩擦焊等几个方面,系统介绍了铝/铜异种材料焊接的研究进展.综合分析表明,熔焊方法不适于铝/铜的焊接,极易出现焊接裂纹和性能降低等问题;铝/铜的压焊应用较为广泛,每种具体的压焊方法各有其特点,应根据上件的结构尺寸加以选定.钎焊方法能成功实现铝/铜的焊接.但需要严格确定钎料成分和钎焊工艺.销/铜的搅拌摩擦焊研究刚刚开始,某些热点M题需要进一步深入研究.但发展前景非常广阔.     

Joining of dissimilar materials with friction stir welding

The welding and joining of dissimilar metals which have very different properties, such as aluminium and carbon steel, is considered to be a subject for research and development in the welding/joining sector continuing into the 21st century. There are also huge requirements and expectations for this sector.¹ Due to the aforementioned, the research and development of welding and joining of dissimilar materials have been carried out over many years; for instance, eutectic bonding of copper pipe and aluminium pipe was developed 30 years ago and this process is still applied for the heat pipes of refrigerators. Recently it has even progressed for applications in joining of wide plate materials of aluminium alloy and stainless steel by means of the vacuum rolling process² and also for weldments of aluminium alloy and carbon steel joined by means of friction welding and employed as automobile components.³ However, there are problems from aspects of cost and restrictions concerning the configurations for which joining is feasible using conventional welding and joining processes and these techniques have not yet reached the stage where they can be applied in a number of industrial sectors. Accordingly, an extensive programme of research and development has been deployed in recent years using fusion welding processes, such as electron beam and laser welding and brazing, diffusion bonding and also friction stir welding (FSW).⁴     

Methods of eliminating pollutant emissions from the work environment in welding and related processes

Abstract

The welding and joining of dissimilar metals which have very different properties, such as aluminium and carbon steel, is considered to be a subject for research and development in the welding/joining sector continuing into the 21st century. There are also huge requirements and expectations for this sector.¹ Due to the aforementioned, the research and development of welding and joining of dissimilar materials have been carried out over many years; for instance, eutectic bonding of copper pipe and aluminium pipe was developed 30 years ago and this process is still applied for the heat pipes of refrigerators. Recently it has even progressed for applications in joining of wide plate materials of aluminium alloy and stainless steel by means of the vacuum rolling process² and also for weldments of aluminium alloy and carbon steel joined by means of friction welding and employed as automobile components.³ However, there are problems from aspects of cost and restrictions concerning the configurations for which joining is feasible using conventional welding and joining processes and these techniques have not yet reached the stage where they can be applied in a number of industrial sectors. Accordingly, an extensive programme of research and development has been deployed in recent years using fusion welding processes, such as electron beam and laser welding and brazing, diffusion bonding and also friction stir welding (FSW).⁴     

铝/钢异种金属Nd:YAG激光-MIG复合热源熔-钎焊接工艺

铝与钢异种金属的优质高效焊接一直是焊接领域的一项技术难题.针对铝与钢焊接的技术困难和特点,提出了可实现铝与钢熔-钎连接的大光斑激光-电弧复合热源焊接方法,用该焊接方法实现了5A02铝合金板与镀锌钢板的优质高效连接.试验结果分析表明,接头钢母材未发生熔化,焊缝与钢母材为钎焊连接,拉伸试样的破坏位置发生在接头铝母材热影响区,接头的抗拉强度与铝合金电弧熔化焊接头强度相当.     

硬质合金与钢焊接技术的研究现状

本文概述了硬质合金与钢焊接中的问题及难点,介绍了硬质合金与钢焊接的国内外研究现状。其中,钎焊和扩散焊是目前连接硬质合金与钢的主要方法,但其接头使用温度受到限制,接头形式也比较单一;而通过采用特殊焊接工艺及焊接材料,利用普通熔焊方法和高能束焊接方法也能实现它们之间的连接,但是在其焊接接头处极易产生裂纹缺陷。因此,这些方法都不能满足使用要求,要获得硬质合金与钢的可靠焊接接头,应从焊接工艺和焊接材料两个方面做进一步的研究。     

Laser fusion welding technology of aluminium alloys

This article deals with recent trends in fusion welding of aluminium dividing the techniques into arc welding and laser welding and hybrid welding combining these. As there have been many reports on welding techniques of welding steel and other metals, it also deals briefly with MIG brazing and laser brazing.     

TiAl基合金与钢连接技术研究进展

TiAl灿基合金具有质轻耐高温的特点，有可能代替Ni基高温合金在发动机中应用，这必然要求解决TiAI基合金与结构钢的连接技术问题。本文综述了以此为应用背景的TiAl基合金与钢连接技术的研究状况，主要涉及摩擦焊、扩散连接以及钎焊等方法，指出了这些方法的特点、最新进展及适用性。     

铝基复合材料焊接的研究现状与展望

介绍了铝基复合材料几种典型的熔化焊、钎焊、固相焊接方法。从焊接的特点,所面临的问题等方面介绍了这几种焊接方法的研究进展,并重点介绍了目前最受关注的搅拌摩擦焊接技术在铝基复合材料中的研究进展。最后展望了这些焊接方法的发展前景。     

Mechanisms of joining aluminium A6061-T6 and titanium Ti–6Al–4V alloys by cold metal transfer technology

Abstract

Cold metal transfer (CMT) welding–brazing joining of Ti6Al4V and Al A6061-T6 was carried out using AlSi₅ wire. The joining mechanisms and mechanical properties of the joints were identified and characterised by scanning electron microscope, energy dispersive spectroscopy and tensile–shear tests. Desired CMT joints with satisfied weld appearances and mechanical properties were achieved by overlapping Ti on the top of Al. The joints had dual characteristics of a welding joint on the aluminium side and a brazing joint on the titanium side. Three brazing interfaces were formed for the joint, which increased the strength of the joint. An intermetallic compound layer was formed at the brazing interface, which included Ti₃Al, TiAl and TiAl₃. Two different fracture modes were also observed: one fractured at the welding/brazing interface and weld metal and the other at the Al heat affected zone (HAZ). Clearly, the joints fractured at the Al HAZ had higher tensile strength than those fractured at the welding/brazing interface and weld metal.     

Fluxless laser beam joining of aluminium with zinc coated steel

Abstract

A laser welding–brazing (LWB) process to join zinc coated steel and aluminium sheets in two different flange geometries is reported. The deep drawing steel sheets are covered by a zinc layer of maximum thickness 10 μm, and a zinc based filler wire was used in the welding experiments with a Nd–YAG laser. Because of the differences in melting temperatures between iron (1808 K), aluminium (933 K), and zinc (693 K), it is possible to weld the aluminium alloy only. Owing to the zinc coating on the steel side, a Zn–Al alloy can be brazed onto the steel without any flux agent. The inevitable formation of a Fe–Al intermetallic phase at the bondline of the weld seam and the steel can be limited to a thickness of less than 5 μm and to a proportion of the contact area only. Mechanical as well as dynamic tests show results comparable to those obtained via other joining techniques. Salt chamber corrosion tests of varnished specimens display minor damage and no decline in tensile strength.