1060纯铝箔作为中间层，通过电阻热辅助超声波缝焊的方式实现1 mm厚度6061铝合金和T2紫铜异种金属焊接，分析了焊接过程中电阻热对铝/铜焊接接头焊缝成形、界面形貌、温度场以及力学性能的影响. 结果表明，采用单独超声波缝焊焊接铝/铜异种金属时，因产生的焊接能量较小，接头连接界面处仅局部区域位置形成连接，接头拉剪强度为45 MPa. 但在电阻热辅助超声波缝焊过程中，电阻热的加入能够有效预热工件，令待焊材料表面发生软化，在高频振动作用下，接头连接界面处形成有效连接. 同时，引入电阻热提高了铝/铜界面处温度，由单独超声波缝焊的140 ℃增加至190 ℃，界面处原子扩散距离增加，获得焊接接头的拉剪强度增加至75 MPa，相对前者接头拉剪强度提高67%.
The 6061 aluminum alloy and pure copper with the same thickness of 1 mm were successfully welded with 1060 pure aluminum foil as the interlayer by resistance heat-assisted ultrasonic seam welding. The effect of resistance heat on the weld appearance, interface morphology, temperature field, and mechanical properties of the welded joints was investigated. The results showed that only local areas were connected at the interface of the Al/Cu welded joints by single ultrasonic seam welding and the tensile shear strength was only 45 MPa, which was attributed to the generated small welding energy in the welding process. However, the workpiece can be successfully preheated by the front resistance heat, which could soften the surface of the material in the resistance heat-assisted ultrasonic seam welding process. Therefore, an effective connection was formed at the joint interface under the function of the high-frequency vibration. Meanwhile, the interface temperature was significantly improved. The temperature at the Al/Cu interface was increased from 140 ℃ to 190 ℃, which increased the atomic diffusion distance at the Al/Cu interface, and the strength of the welded joint was significantly improved. The tensile shear strength reached 75 MPa, which was 67% higher than that of single ultrasonic seam welding.
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