基于激光——MIG复合热源的5A02铝合金/镀锌钢熔——钎焊  

Fusion-brazing Joining for Dissimilar Metals Between 5A02 Aluminium Alloy and Zinc-coated Steel Based on Laser-MIG Hybrid Welding

作　　者：雷振[1] 秦国梁[1] 林尚扬[1] 王旭友[1] 

机构地区：[1]哈尔滨焊接研究所,哈尔滨150080

出　　处：《机械工程学报》2009年第3期94-98,共5页Journal of Mechanical Engineering

基　　金：国家"十一五"科技支撑计划资助项目(2006BAF04B10)

摘　　要：基于激光—MIG复合热源焊接技术实现了5A02铝合金/镀锌钢异种金属板材的优质、高效熔—钎焊接,并对焊缝的成形、接头性能及微观结构作了分析。分析结果表明,该焊接技术可以实现5A02铝合金/镀锌钢的高速熔—钎焊接,最高焊接速度可达5m/min,焊接接头中镀锌钢母材未发生熔化,铝焊缝与镀锌钢母材为钎焊连接;焊接接头的抗拉强度可达153.1MPa,约为5A02铝合金母材抗拉强度的75.7%,接近于该铝合金熔化焊接头的强度;拉伸试验中试样断裂在焊缝铝合金母材热影响区,接头的断裂主要是塑性断裂,但有脆性断裂的痕迹。对接头的组织和结构进行分析表明:焊缝钎接界面处生成了一薄层Al-Fe金属间化合物,化合物层的平均厚度约为1.51μm,生成的金属间化合物主要为Fe3Al、FeAl2、Fe2Al5、FeAl3,并且在这些化合物的周围会产生Si元素的富集。High efficiency and quality fusion-brazing joining between 5A02 aluminium alloy and zinc-coated steel sheet, based on laser-MIG hybrid welding, is successfully done. The seam appearance and the mechanical properties as well as the microstructures of the joints are analyzed. The results indicate that a high speed fusion-brazing joining can be achieved with this welding method, and the highest welding speed is up to 5 m/min. A brazed joint between the aluminium alloy and the steel is formed, and the stee 1 sheet under the seam is not melted. The top tensile strength of the joint is 153.1 MPa, about 75.7% of that of the aluminium alloy base metal. It is almost as high as that of the aluminium alloy＇s fusion joint. In tensile test, the specimen fracture is in the heat-affected zone of aluminium aside. It can be sure that the main fracture form of the joint is ductile fracture, but has the trace of brittle fracture. The analysis on the microstructure of joint shows that a thin intermetallic compound layer is generated on the brazing interface, but its average thickness is only about 1.51 μm. It＇s confirmed that the compound layer is composed of Fe3Al, FeAl2, Fe2Al5 and FeAl3, and the zone of these intermetallic compounds abounds in silicon.

关 键 词：激光 MIG电弧 复合热源 异种金属 熔-钎焊接 

分 类 号：TG457[金属学及工艺—焊接]