双光束激光-TIG复合焊电弧特性分析

从TIG电弧波动特征方面分别研究了铝合金高功率单光束激光-TIG复合焊和双光束激光-TIG复合焊焊接过程的差别。试验结果表明,双光束-TIG复合焊的电弧电压分布更集中,即双光束-TIG复合焊的电弧电压相对稳定。在试验条件下,当焊接参数相同时,双光束-TIG电弧电压的变异系数随激光功率的增加而减小,单光束-TIG的电弧电压变异系数随激光功率的增加而增加,并且在激光功率密度较小时,单光束-TIG的电压变异系数小于双光束-TIG及单TIG。在激光功率密度较大时,电压变异系数为单光束-TIGTIG双光束-TIG;在相同的焊接参数下,双光束激光-TIG复合焊的焊缝表面成形较单光束激光-TIG复合焊的均匀连续。     

双光束激光焊匙孔动态特征分析

文中研究了高功率单光束激光焊与双光束激光焊过程中匙孔动态特征的差别. 结果表明,单光束激光焊及双光束激光焊接过程中匙孔均处于从产生到湮灭的剧烈波动的过程,不同于单光束激光焊匙孔的形成、长大、维持、缩小、湮灭过程,双光束激光焊的匙孔还存在分离长大及合并缩小的过程;在相同的焊接参数及焊缝具有相同熔深的条件下,双光束激光焊匙孔的波动频率约为单光束激光焊的2/3,单光束激光焊匙孔的开口面积均值约为双光束激光焊匙孔开口面积的1/2,开口面积的波动变异系数约为单光束激光的2倍,即双光束激光焊过程中匙孔较单光束激光焊的具有较高稳定性.     

铝合金双光束激光焊接过程稳定性分析

从成形、气孔、熔深的波动、激光匙孔、光致等离子体、飞溅等方面研究了铝合金高功率单光束激光和双光束激光焊接过程的稳定性。结果表明,在相同工艺参数下,双光束激光焊缝表面成形明显优于单光束,熔深的波动较单光束小;在相同工艺参数及相同熔深条件下,双光束焊缝气孔率较单光束小,小孔及等离子体的波动周期较单光束长,面积波动变异系数较单光束小,飞溅较单光束更加细小均匀。     

双光束激光填丝焊工艺对铝合金焊接气孔率的影响

以LF6铝合金为材料,CO2激光为热源,开展了双光束激光填丝焊气孔特性分析.与单光束激光填丝焊及双光束自熔焊相比,双光束激光填丝焊能够抑制气孔的产生,尤其是并行双光束激光焊抑制气孔效果更明显.在此基础上进一步分析了保护气体成分和激光能量对焊接气孔率的影响.结果表明,采用氦气保护时,等离子体对激光的屏蔽作用小,能够稳定焊接过程;激光功率过大或者过小都会导致匙孔的不稳定,造成焊缝气孔率增加.     

铝合金激光-MIG复合填丝焊稳定性分析

通过与铝合金激光-MIG复合焊方法相对比,主要研究了铝合金激光-MIG复合填丝焊的焊缝成形、熔深稳定性、余高稳定性、焊缝气孔率、激光匙孔特征、等离子体特征. 试验结果表明,在合适的工艺参数条件下,铝合金激光-MIG复合填丝焊焊接过程稳定,焊缝成形良好,额外填入的焊丝可以连续稳定地过渡到熔池中,激光匙孔具有明显的形成、长大、湮灭周期性变化特征;相同工艺参数条件下,铝合金激光-MIG复合填丝焊的焊缝熔深稳定性、余高稳定性与激光-MIG复合焊相当,激光匙孔开口面积约增加15.34%,等离子体+电弧总面积约增加1.95%.     

AZ31B镁合金的几种激光焊接特性研究

采用激光焊、激光-TIG、激光-MIG及激光-超声4种焊接方法对AZ31B镁合金进行焊接,并讨论分析4种焊接方法下的镁合金焊接特性、微观组织以及力学性能。结果表明,激光焊焊缝下塌严重,激光复合焊接技术(激光-TIG、激光-MIG和激光-超声)则能显著改善焊缝下塌缺陷,得到成形良好的连续焊缝。激光复合焊接可有效减小焊缝中的气孔缺陷,其中激光焊焊缝中气孔率为4.3%,激光-TIG和激光-MIG焊缝中气孔率分别为3.4%和3.9%,而激光-超声焊缝中气孔率最低,仅为0.9%;同时,施加超声有助于细化焊缝晶粒尺寸,提高焊接接头的力学性能,接头强度可提高至母材的88.9%,与激光焊相比,提高了7.7%。     

不同焊接方法对E690海工钢气孔规律的影响

E690海工钢采用激光锻造电弧复合焊进行焊接修复。通过显微硬度、残余应力检测评价电弧焊、单光束激光锻造电弧复合焊和双光束激光锻造电弧复合焊3种焊接方法的力学性能和焊缝形貌。采用电弧焊,焊缝产生较多气孔和未熔合;单光束激光锻造电弧复合焊试验表明,经过热力耦合作用,焊接电流、电弧电压分别为108 A和40 V,可以焊接坡口宽度4 mm、坡口深度5 mm的焊缝,进一步增加了焊缝的熔深和熔宽,并且减少了气孔的大小和数量;使用双光束激光锻造电弧复合焊可以在焊接电流、电弧电压平均值分别为70.25 A和33.58 V的情况下有效抑制气孔和裂纹的产生。同时研究了激光波长对焊缝成形的影响,当两束激光波长均为532 nm,激光能量500 mJ,频率为10 Hz,焊道表面及截面形貌的力学性能最佳。     

其它焊接方法

20092154基于视觉传感的激光-MIG复合焊熔透闭环控制/双元卿…//清华大学学报:自然科学版.-2008,48(11):1891~1894在对接焊中,坡口间隙的波动会导致焊接熔透状态的变化,为保证稳定的熔透,需要对焊接熔透状态进行实时检测和控制。针对CO2激光-MIG复合对接焊,建立了基于视觉传感和DSP的熔透状态实时检测与控制系统,获取了清晰的熔池背面图像,经过适当的处理得到了熔池背面熔宽的信息,并通过调节焊接速度或控制电弧电流,对熔透状态进行了控制。结果表明:即使在间隙明显波动的情况下也获得了熔透可靠、背面熔宽均匀的焊缝,从而实现了复合对接焊熔透状态的闭环控制。图12参620092155基于有限元的镁合金弧焊过程分析/齐铁力…//热加工工艺.-2008,37(13):82~84根据TIG焊接和激光-TIG复合热源焊接的物理特征,建立了基于TIG焊接过程的高斯面热源模型和基于激光-TIG复合热源焊接的新型双热源模型,分析了两种焊接方法对应的热源模型的特点。在此基础上,针对AZ31B镁合金,进行了单独TIG焊接和复合热源焊接温度场数值模拟及焊缝区微观组织分析,提出了其热源模型建立过程中的参数修改建议。通...     

其它焊接方法

20092154基于视觉传感的激光-MIG复合焊熔透闭环控制/双元卿…//清华大学学报:自然科学版.-2008,48(11):1891~1894在对接焊中,坡口间隙的波动会导致焊接熔透状态的变化,为保证稳定的熔透,需要对焊接熔透状态进行实时检测和控制。针对CO2激光-MIG复合对接焊,建立了基于视觉传感和DSP的熔透状态实时检测与控制系统,获取了清晰的熔池背面图像,经过适当的处理得到了熔池背面熔宽的信息,并通过调节焊接速度或控制电弧电流,对熔透状态进行了控制。结果表明:即使在间隙明显波动的情况下也获得了熔透可靠、背面熔宽均匀的焊缝,从而实现了复合对接焊熔透状态的闭环控制。图12参620092155基于有限元的镁合金弧焊过程分析/齐铁力…//热加工工艺.-2008,37(13):82~84根据TIG焊接和激光-TIG复合热源焊接的物理特征,建立了基于TIG焊接过程的高斯面热源模型和基于激光-TIG复合热源焊接的新型双热源模型,分析了两种焊接方法对应的热源模型的特点。在此基础上,针对AZ31B镁合金,进行了单独TIG焊接和复合热源焊接温度场数值模拟及焊缝区微观组织分析,提出了其热源模型建立过程中的参数修改建议。通...     

激光-TIG复合热源焊接钛合金T形结构焊缝成形特点及影响因素分析

采用激光-TIG弧复合焊接工艺对钛合金T形结构单面焊背面双侧一次成形焊接新技术进行了研究,通过综合试验、对比分析等方法,研究了多种试验条件下T形结构焊缝成形特点及影响因素,给出了采用激光-TIG复合焊接工艺实现钛合金T形结构单面焊背面双侧一次成形焊接的最佳工艺方案.结果表明,采用激光-TIG复合焊接工艺焊接钛合金T形结构与钨极氩弧熔透焊工艺相比在焊缝组织、焊接效率、焊缝成形、间隙适应性等方面有明显的优势.     

镁铝异种金属激光-TIG复合热源焊焊接性分析

采用激光-TIG复合热源和TIG焊接异种金属镁和铝，利用X射线衍射仪、金相显微镜和扫描电镜研究镁和铝焊接接头的微观组织、元素分布。结果表明，TIG焊接镁和铝形成连续的金属间化合物层，导致镁和铝接触的界面开裂，不能实现有效的连接。激光-TIG复合热源由于其焊接速度高和对熔池的快速搅拌作用，使镁和铝形成的金属间化合物由连续的层状变成弥散的状态，改善了异种金属镁和铝的焊接性。镁和铝激光-TIG复合热源焊接的焊缝成形均匀，美观。     

Characteristics of 5A90 Aluminum-lithium Alloy by YAG-MIG Hybrid Welding

The characteristics of 5A90 Aluminum-Lithium alloy by YAG laser and MIG arc hybrid welding (Hybrid welding) were studied.Compared with the laser beam welding (LBW),the hybrid welding could not only improve the weld appearance significantly,but also have better engineering compatibility.The obvious microstructure characteristics of joint by the hybrid welding are fine-grained layer near fusion-line and the equiaxed grain in most area of welded seam.The subgrains of the equiaxed grains,located in the weld center,tend to coarse from bottom to top of weld joint.The microhardness of welded seam by the hybrid welding (83.57HV0.2) is lower than that by LBW (95.65HV0.2),but the uniformity of the former is better than that of the latter.The ultimate strength and the elongations after fracture of the joint by the hybrid welding are lower than that by LBW.The tensile fracture always occurs in HAZ or weld centerline,and the fractography presents mixture rupture.Therefore,if the combined mechanical properties of joint by the hybrid welding meet the operation requirements,it should be improved by reasonable artificial aging or heat treatment after welding,and it also should develop a better filler wire matched with the base metal.     

Microstructure and mechanical properties of wrought magnesium alloy AZ31B welded by laser-TIG hybrid

The laser-TIG hybrid welding was mainly used to weld the wrought magnesium alloy AZ31B. The tech-nical characteristics of laser-TIG hybrid welding process was investigated and the interactional mechanism between laser and arc was discussed, at the same time the microstructure and mechanical properties of the wrought magnesi-um alloy AZ31B using laser-TIG hybrid welding were analyzed by optical microscope, EPMA, SEM, tensile ma-chine, hardness machine. The experimental results show that the presence of laser beam boosts up the stability of the arc during high speed welding and augments the penetration of weld； the crystal grains of magnesium alloy weld are fine without porosity and cracks in the best welding criterion and the microstructure of HAZ does not become coarse obviously. The elements profile analysis reveals that Mg content in the weld is lower than that of the base metal, but Al content is higher slightly. Under this experimental condition, the wrought magnesium alloy AZ31B joint can be achieved using laser-TIG hybrid process and the tensile strength of the joint is equivalent to that of the base metal.     

工业纯钛光纤激光-MIG复合焊接工艺及性能

采用光纤激光与熔化极惰性气体保护电弧焊(MIG焊)复合焊接工业纯钛,分别对激光焊、MIG焊和复合焊接头的焊缝表面成形、横断面进行了观察,并进行了激光焊和复合焊接头的拉伸试验及杯突试验.结果表明,复合焊的电弧稳定性比MIG焊显著提高,焊接速度可提高7倍;复合焊与激光焊接头的抗拉强度高于母材;复合焊接头的杯突值优于激光焊接头的杯突值,这是因为复合焊焊缝的微观组织有利于接头的塑性.因此,采用光纤激光-MIG电弧复合焊接方法很好地实现了工业纯钛的高速焊接,焊缝成形良好,接头的塑性优于单一激光焊的塑性.

Abstract：

Fiber laser-metal inert gas (MIG) arc hybrid welding was used to weld the commercial pure titanium (CP-Ti). The weld appearance, cross section, tensile strength, Erichsen value and microstructure of the CP-Ti welded joints were studied. The results show that the arc stability is substantially improved and the welding speed can be increased to 7 times by fiber laser-MIG hybrid welding. The welded joints by laser welding and the hybrid welding exhibit the higher ultimate tensile strength than those of the base metal. In addition, the welded joint by the fiber laser-MIG hybrid welding has higher Erichsen values than that by laser joints. The difference in plasticity is attributed to the microstructure changes in the welded joint of hybrid welding. Thus, the fiber laser-MIG hybrid welding of CP-Ti can be carried out suecessfully at higher welding speed with a good combination of weld bead appearance and plasticity.     

低功率YAG激光-TIG电弧复合焊接镁合金薄板工艺

以2 mm厚AZ31B变形镁合金薄板为研究对象开展低功率脉冲YAG激光-TIG电弧复合热源焊工艺研究,分析了激光与电弧的能量匹配对焊缝成形的影响规律.结果表明,镁合金薄板低功率YAG激光-TIG电弧复合热源焊接过程中,激光能量与电弧能量之间的相互匹配将直接影响焊缝的表面成形,获得理想焊接接头的工艺参数区间相对较狭小.为使焊缝成形均匀连续,焊接过程中需要对焊缝背面采用氩气进行保护,当保护气体流量为5～10 L/min时获得了具有最佳性能的焊接接头,其拉伸载荷达到镁合金母材的95%以上.     

Nd:YAG激光+CMT电弧复合热源横焊工艺参数对焊缝形貌的影响

以304不锈钢为对象,借助横焊焊缝横断面图像来分析Nd:YAG激光+CMT电弧复合热源横焊焊缝横断面的成形特征,研究了Nd:YAG激光+CMT电弧复合热源横焊过程中焊接工艺参数对焊缝横断面形貌的影响.结果表明,在Nd:YAG激光+CMT电弧复合热源横焊中,焊接工艺参数对横焊焊缝横断面形貌的影响显著;Nd:YAG激光加入CMT电弧焊中明显提高了复合焊缝以及复合焊中CMT焊缝的熔深;采取适当的焊接工艺参数(小的光丝间距、大的激光功率、小的焊接速度、适合的离焦量以及小的或大的CMT功率)可以避免熔池机械式叠加和焊缝横断面错位现象,使得焊缝成形良好.     

CO2 laser-micro plasma arc hybrid welding for galvanized steel sheets

A laser lap welding process for zinc-coated steel has a well-known unsolved problem-porosity formation. The boiling temperature of coated zinc is lower than the melting temperature of the base metal, which is steel. In the autogenous laser welding, the zinc vapor generates from the lapped surfaces expels the molten pool and the expulsion causes numerous weld defects, such as spatters and blow holes on the weld surface and porosity inside the welds. The laser-arc hybrid welding was suggested as an alternative method for the laser lap welding because the arc can preheat or post-heat the weldment according to the arrangement of the laser beam and the arc. CO₂ laser-micro plasma hybrid welding was applied to the lap welding of zinc-coated steel with zero-gap. The relationships among the weld quality and process parameters of the laser-arc arrangement, and the laser-arc interspacing distance and arc current were investigated using a full-factorial experimental design. The effect of laser-arc arrangement is dominant because the leading plasma arc partially melts the upper steel sheets and vaporizes or oxidizes the coated zinc on the lapped surfaces. Compared with the result from the laser-TIG hybrid welding, the heat input from arc can be reduced by 40%.     

活性剂对激光-电弧复合焊接的影响

提出了激光-电弧复合活性焊接法,以提高小功率激光-电弧复合焊接的熔深.在待焊不锈钢表面涂覆一层活性剂,然后进行激光-电弧复合焊接.研究了工艺参数对焊缝成形性的影响,并对焊接接头的组织性能进行了分析.结果表明,涂覆活性剂后可以使复合焊接的熔深增加,并且可以细化复合焊焊缝组织.复合焊接头与复合活性焊接头的显微硬度变化规律一致.复合活性焊接头的抗拉强度较高,达到母材抗拉强度的92%.复合活性焊接头的腐蚀速率低于复合焊接头的腐蚀速率,具有良好的耐蚀性能.     

Novel hybrid method： pulse CO2 laser-TIG hybrid welding by coordinated control

0IntroductionRecently,laser-arc hybrid welding,as a rising spe-cial manufacture technology,has attracted more and moreinterest and attentions of some researchers and weldingcompanies.But,concerning laser-TIG hybrid welding,most of the research in this area mainly focused on contin-uous wave laser-TIG arc hybrid welding[1-3].In previousworks,because of the absorption and defocusing of laserenergy by hybrid arc plasma,the energy loss of laser wasvery serious when laser traversed arc in continu…