共查询到15条相似文献,搜索用时 60 毫秒
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以铝硅共晶合金Al-12Si为填充材料,采用光纤激光-冷金属过度(CMT)复合焊接技术制备铝/钢异种金属优质对接接头。通过SEM、EDS和XRD分析,结果表明:不锈钢和熔合区界面存在明显的金属间化合物(IMCs)层。从接头上部到下部,IMCs界面层逐渐增厚,并由锯齿状变成板块状。IMCs层通常表现为两层结构,分别为靠近钢基体侧的θ-Fe4(Al,Si)13层和靠近焊缝侧的τ5-Al8(Fe,Cr)2Si层组成。当激光偏移量为0.4 mm时,热输入的优化范围为80~110 J/mm。在此范围内,IMCs界面层厚度范围为3~8.5μm,接头抗拉强度大于130 MPa,达到铝母材的80%以上。 相似文献
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铝/钛异种合金激光熔钎焊接头界面特性 总被引:5,自引:0,他引:5
以铝硅共晶合金为填充材料,采用激光熔钎焊的方法对铝/钛异种合金进行焊接,获得了同时具有熔焊和钎焊双重特征的焊接接头。由于激光局部加热并且有很高的冷却速度,发现在钛合金附近的钎焊界面形成了特殊的形态结构。结果表明,获得的钛合金钎焊区界面金属间化合物厚度很薄,仅在10μm以下。焊缝上部界面金属间化合物较厚,主要呈锯齿状;焊缝下部界面金属间化合物厚度不足1μm,呈薄层状。界面金属间化合物的主要成分为TiAl3,以Ti(SiAl1-x)3结构的置换固溶体形式存在。底部界面容易成为裂纹产生的源头,裂纹多沿界面附近焊缝中的共晶组织扩展,接头的平均抗拉强度为铝母材的85%左右。 相似文献
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异种金属焊接接头开裂是导致核电事故的主要原因,急需开发新材料新技术,提高焊缝质量。传统电弧焊方法存在效率低、热输入大和变形严重等问题。窄间隙电弧焊的热输入、填充量、变形量等都比传统电弧焊低。与窄间隙电弧焊相比,窄间隙激光填丝焊坡口更窄、热输入更低、变形更小、精度更高。研究表明,窄间隙激光填丝焊可获得满足核电压力容器制造要求的焊缝,有望成为异种金属连接新方法。然而,现有窄间隙激光填丝焊采用常规激光及单焊丝填充,仍存在3个主要问题:一是界面容易产生未熔合问题;二是熔融金属粘度大,熔池流动性差,合金元素分布不均匀;三是低熔点共晶相沿晶界析出过多,无法兼顾焊缝抗液化裂纹、应力腐蚀裂纹和高温失塑裂纹能力。研究表明,焊接热源和焊材是解决上述问题的2个关键因素。创新点:(1)系统论述了核电异种金属焊接材料的发展及其趋势。(2)窄间隙激光焊接有潜力成为核电异种金属连接的新方法。(3)焊接热源和焊材是解决窄间隙激光填丝焊界面未熔合、熔池流动性差低及低熔点共晶相沿晶界析出过多等问题的2个关键因素。 相似文献
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高频感应焊接的特点及其在异种金属焊接中的应用 总被引:2,自引:0,他引:2
回顾了高频感应的定义和发展,介绍了高频感应加热焊接的基本原理和其加热速度快,焊接热影响区小,能量集中,冷却时间短以及环保、节能等特点.针对异种金属焊接存在的难点,综述了常用的焊接方法及其优缺点.高频感应焊的快速加热和表面集肤效应的特点,使其能够实现异种金属钎焊和表面熔覆焊的冶金结合,接头性能优良.指出感应圈的形状及其与... 相似文献
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将激光一电弧复合热源焊接应用于铜与钢的熔一钎连接,用该焊接方法实现了T2紫铜合金板与镀锌钢板的优质连接。结果表明,焊接接头钢母材未发生熔化而铜合金母材熔化,其焊缝与钢母材为钎焊连接,拉伸试验中试样的断裂位置发生在焊缝铜母材热影响区,焊接热影响区略有软化。断口分析发现,接头的断裂属于塑性断裂。高倍电镜分析表明,焊缝钎焊连接界面处未见钢溶蚀及Cu沿铁素体晶界侵入现象;能谱分析结果表明,焊接接头中Cu,Fe原子分别向对方基体进行了良好的扩散,二者在钎焊连接界面处形成了Cu—Fe固溶体,并且在接头的钎焊连接界面处有Si元素的富集现象。 相似文献
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Dissimilar metal joining between 5A02 aluminum alloy and H62 brass sheets was conducted by gas tungsten arc welding with Zn-15% Al and Al-12% Si flux-cored filler wires. The microstructure in the weld and distribution of major alloying elements in the intelfacial layer were examined, and the tensile strength of the resultant joints was measured. Pores appeared in the weld made with Zn-15% Al flax-cored filler wire, the interracial layer mainly consisted of AlCu phase, and the specimens fractured through the weld with tensile strength of 129 MPa. When Al-12% Si flux-cored filler wire was used, Cu diffused into the weld and Al2 Cu phase formed, and the specimens fractured along the interfacial layer with tensile strength of 122 MPa. 相似文献
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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。 相似文献
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Tetsuo Suga Yasuoa Murai Taizo Kobashi Kunika Ueno Minoru Shindo Katsunori Kanno 《Welding International》2016,30(3):166-174
In many industries, there are applications that require the joining of stainless steel and copper components; therefore, the welding of dissimilar stainless steel/copper joints is a common process. For this investigation, the optimal brazing conditions and suitable filler metals for laser brazing of stainless steel/copper lap joints were studied. Tensile shear force increases with increases in the laser spot diameter or in the laser irradiation angle, which is associated with increased bonding width; however, as bonding width approaches 2 mm, tensile shear force reaches a saturated value due to fracturing at the HAZ of the Cu base plate. In order to obtain joints with high tensile shear strength, laser brazing was optimized by using Cu–Si-based filler metal under the following conditions: laser power, 4 kW; spot diameter, 3 mm; laser irradiation angle, 80°; irradiation position shift, 0.6 mm; brazing speed, 0.30 m/min; and filler metal feed speed, 0.30 min. Concerning filler metals, it was found that the Ni–Cu type showed relatively large tensile shear force even at high welding speeds in comparison with those of the Cu–Si, Cu, Cu–Ni, Ni–Cu and Ni types, respectively. 相似文献
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激光焊接中激光聚焦技术的研究 总被引:1,自引:0,他引:1
激光焊接中,激光聚焦特性的好坏是影响焊接质量的关键因素。本文首先对透射聚焦和反射聚焦进行了概述,然后对一些新的聚焦技术如多焦点技术、旋转焦点技术等进行了介绍,并分析了多焦点技术对激光焊接速度和焊缝质量的影响,证明多焦点技术的优越性。 相似文献
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Koji Nishimoto Tomoki Harano Yoshihiro Okumoto Ken Atagi Hiroo Fujii Seiji Katayama 《Welding International》2013,27(11):817-823
Dissimilar metal joints of Zn-coated Galvannealed steel (GA steel) and commercially available pure aluminium (A1050) sheets were produced by changing the laser power and the roller pressure by the laser pressure welding method. By this method, the YAG laser beam was irradiated into a flare groove made by these dissimilar metal sheets. In addition, the laser beam was scanned at various frequencies and patterns through the fθ lens using two-dimensional scanning mirrors. Then the sheets were pressed by the pressure rolls to be joined. The compound layers in the weld interface were observed by an optical microscope and the layer thicknesses were measured. The thicknesses ranged from 7 to 20 μm. The mechanical properties of the welded joints were evaluated by the tensile-shear test and peel test. In the tensile-shear test, the strengths of the joints produced under the most welding conditions were so high that the fracture occurred through the base aluminium sheet. In the peel test of the specimens subjected to a laser beam of 1200–1400 W power under roller pressure of 2.94 kN, the specimen fracture took place in the base aluminium sheet. Even if the compound layer was thick, high joint strength was obtained. On the other hand, the specimen fractured in the weld interface at a laser power of 1500 W. The results of X-ray diffraction on the peel test specimen surface identified that the intermetallic compound on the GA steel side was Fe2Al5Zn0.4. Moreover, the aluminium parts adhering to the GA steel side were confirmed. These results suggest that the fracture in the peel test occurred between the compound layer and A1050 and partly in the base aluminium. A micro-Vickers hardness test was performed to examine the hardness distribution in the compound layer. The hardness values near A1050 and GA steel were about 100 and 470 Hv, respectively, which suggests that the compound layer should not necessarily consist of brittle intermetallic compounds. It is therefore concluded that laser pressure welding could produce high strength joints of GA steel and A1050 dissimilar materials. 相似文献