(1. 哈尔滨工业大学(威海) 山东省特种焊接重点实验室,威海 264209;
2. 哈尔滨工业大学先进焊接与连接国家重点实验室,哈尔滨 150001)
摘 要: 采用Zn-2%Al(质量分数)药芯焊丝对5052铝合金和H62黄铜进行TIG熔钎焊搭接试验,并对接头显微组织、界面层结构及力学性能进行分析。结果表明:Zn-2%Al药芯焊丝在黄铜母材表面润湿性良好,能够获得较好的铝/黄铜熔钎焊接头。在黄铜侧过渡区形成块状和条状的AlCu脆性金属间化合物相,同时在黄铜侧界面处形成Cu9Al4、CuZn金属间化合物层。随焊接热输入的增大,界面层厚度先增大后减小,接头拉伸载荷也是先增大后减小。焊缝中心区及界面层的显微硬度高于铝和黄铜母材的。接头拉伸时断于黄铜侧界面区,且断口为解理断裂。
关键字: 铝/黄铜异种金属;TIG熔钎焊;药芯焊丝;显微组织;力学性能
(1. Shandong Provincial Key Laboratory of Special Welding Technology,
Harbin Institute of Technology at Weihai, Weihai 264209, China;
2. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China)
Abstract:5052 aluminum alloy and H62 brass dissimilar metals were welded by TIG welding-brazing lap using Zn-2%Al (mass fraction) flux-cored wire. Microstructure, interface layer structure and mechanical properties of the joint were studied. The results show that favorable welding-brazing joints are obtained due to the excellent wettability of molten Zn-2%Al on the surface of brass. The massive and strip AlCu intermetallic compounds (IMCS) form in the transition zone at the brass side, meanwhile, Cu9Al4 and CuZn intermetallic compound layers form at the interface. The interface layer thickness and tensile load of joint increase at first and thendecrease with the increase of welding heat input. The micro-hardnesses of weld center and the interface layer are higher than those of aluminum and brass base metals. Tensile test results show that the joint fractures at interface layer of the brass side with cleavage fracture surface.
Key words: Al/brass dissimilar metals; TIG welding-brazing; flux-cored wire; microstructure; mechanical property