Cu is widely used in electronics, machinery and other fields because of its excellent mechanical properties and ductility. Nevertheless, as a worldwide scarce resource, especially in China, we are dependent on imports to a large extent. In order to reduce the cost of manufacturing, it is finding other metals to replace Cu that has become a hot research trend. Fortunately, Al resources are abundant in China, with which the weight and cost of components can be significantly reduced compared with those of Cu. However, due to the large difference in physical properties between them, the residual stress is easy to be generated at the interface, which affects the reliability of the connector. Additionally, the temperature of traditional welding method is relatively high, which easily leads to the softening and deformation near the Al side. Quite a few industries are faced with the problem of Al connection difficulty. Therefore, researchers have noticed a kind of filler metal with great potential for application ———Zn-Al solder. The melting temperature can be controlled by changing the Al content, which is more flexible to meet the welding requirements under different circumstances, and quite suitable for the connection of Cu/Al and other metals. In this paper, the research progress and development trend of Zn-Al filler metal alloying are reviewed. The existing research results are analyzed and summarized from the aspects like microstructure and mechanical properties. In the meanwhile, the existing issues are pointed out, and the future research work is anatomized and prospected. It is expected that Zn-Al filler metal can solve the problems of Cu/Al connection as soon as possible, so as to alleviate the shortage of Cu resources and reduce production cost. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.
