Reaction mechanism and microstructure of interface in soldered joint of zinc-based alloy

The micro-region compositisions, fine microstructure and phases of interface region in joint soldered with new solder and flux self-developed were studied by means of XRD, EPMA, TEM and SEM.The results show that the interface region mainly consists of diffusion zone and dissolution zone.There was more Cd based solid solution(1.44% Zn) in diffusion zone, while more Zn based solid solution in dissolution zone.The interface region mainly consists of Cd, Sn, Zn, Al solid solution, and oxides such as SnO, SnO₂, CdO and metallic compounds such as MgZn, Mg₂Sn, Al₄Cu₉ and Mg₂Cu₆Al₅.No continuous intermetallic compounds layer which would seriously impair the properties of the soldered joint is found.