Research Status of Brazing Filler Metals for Cu/Al Brazing

With the increasingly widespread application of dissimilar metal composite structural components, achieving high-quality welding of Cu/Al dissimilar metals is of great significance for economic and lightweight development in the indus trial field. Due to its advantages of low heat input, high material compatibility, and small thermal deformation of welded parts, brazing has a good application prospect in the field of dissimilar metal material welding. Based on the analysis of the characteristics of Cu/Al dissimilar metal brazing, the advantages, limitations, and latest research progress of Al-Si, Sn-Zn, and Zn-Al brazing filler metals in the application of Cu/Al dissimilar metal connections were reviewed. The effects and mechanisms of alloying and adding rare earth elements on the microstructure and mechanical properties of brazing filler metals and Cu/Al brazed joints were introduced. The problems and solutions encountered in the future research were summarized, and the research direction in the field was prospected.