铝镍作为重要的电极材料，研究其连接机理和接头优化工艺具有良好的应用前景. 对1A99铝合金和N4镍合金异种金属进行超声波焊接工艺研究，重点分析焊接能量对接头力学性能、宏观形貌、原子扩散和断裂模式的影响. 结果表明：在超声波焊机的高频振动作用下，能实现铝镍异种金属的有效连接. 当焊接能量为600J时，接头的拉伸载荷可达到1121N；超声波焊接过程中，铝侧发生软化，而镍侧硬度略微提高；铝侧的压痕深度随能量的提高而增加，当能量达到700J时，接头沿厚度方向发生变形. 扫描电子显微镜(SEM)和能谱仪(EDS)分析表明，在优化的焊接参数下，铝镍界面接合区域存在厚度为 5.29μm的过渡层，发生了机械嵌合现象，没有金属间化合物的形成. 本研究解决了采用传统熔焊方法导致铝镍异质金属接头脆化的问题，为促进铝镍电极材料的发展奠定理论基础.
Aluminum-nickel is an important electrode material which has good application prospects to study the bonding mechanism and optimization technology of the joints. Ultrasonic welding of dissimilar metals, 1A99 aluminum alloy and N4 nickel alloy, were conducted in this research. The effect of welding energy on mechanical properties, macro morphology, atomic diffusion and fracture mode of the welded joints have been analyzed emphatically. The results show that under the high-frquency ultrasonic vibration, a sound aluminum to nickel ultrasonic welding joint is successfully obtained. The maximum tensile shear load of joint can reach 1121N at the welding energy of 600J. The hardness profile of aluminum side which is close to the sonotrode tip is decreased, while the hardness of nickel side is slightly increased during the welding process. By increasing the welding energy, the indentation depth on aluminum side is increased, and significant deformation of joints in the thickness direction is observed when the energy reaches 700J. The scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) analysis show that a 5.29μm thick transition layer in the faying interface between Al and Ni is found under the optimized welding parameters. And there is no intermetallic compound (IMC) formed in the joint. The brittleness problem of Al-Ni dissimilar metal joints caused by traditional fusion welding methods is solved in this study, which lays a theoretical foundation for promoting the development of Al-Ni electrode materials.
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