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为了提高Sn-9 Zn-Cu钎料的润湿性和焊接强度,通过添加一定量稀土La-Ce合金元素,选用较合适的钎剂和优化后的工艺,研究了RE的加入对Sn-9 Zn-0.3 Cu钎料钎焊6061铝合金组织和剪切强度的影响。通过焊接接头扫描电镜(SEM)和能谱(EDS)分析组织形貌和成分,对接头进行拉伸试验并观察断口组织。结果表明,RE的加入改善了钎料组织,减缓富铜相的团簇,细化晶界中的富锌相,阻止Cu6Sn5的产生。RE的加入对富锌相的影响较小,降低了铝向钎料的扩散,增大了钎料向铝工件的溶解,使得钎料与铝件吸附更加牢靠;焊接接头良好,拉伸试验得出RE含量在0.2%时较佳,抗剪切强度提高34%倍.。断裂面都在钎料中,随着RE从0.1%增加到0.2%出现典型的韧性断裂,添加量在0.4%RE时有大量的β-Sn产生,钎料氧化严重,氧化Ce成为断裂源。
In order to improve the wettability and welding strength of Sn-9Zn-Cu solder, by adding a certain amount of rare earth La-Ce alloy elements, choosing the proper flux and the optimized process, the effects of RE addition on Sn-9 Effect of Zn-0.3 Cu Brazing on Microstructure and Shear Strength of 6061 Aluminum Alloy. Tissue morphology and composition were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Tensile tests were performed on the joints and the fracture tissues were observed. The results show that the addition of RE improves the microstructure of brazing filler metal, slows the growth of copper-rich phase clusters, and fills the zinc-rich phase in grain boundaries to prevent the formation of Cu6Sn5. The addition of RE has little effect on the Zn-rich phase, reducing the diffusion of aluminum to the brazing filler metal, increasing the dissolution of the brazing filler metal to the aluminum workpiece, and making the brazing filler metal and the aluminum component adsorb more firmly; the welding joint is good and the tensile test The RE content is better at 0.2% and the shear strength is increased by 34%. The fracture surfaces are all in the brazing filler metal. Typical ductile fracture occurs with the increase of RE from 0.1% to 0.2%. A large amount of β-Sn is produced when the amount of RE is 0.4% RE. The oxidation of the brazing filler metal is serious and Ce oxide is the source of fracture.