Effect of element Sn and Cu on microstructure and mechanical properties of Zn-10Al solder

The Cu element was added to the Zn-10Al matrix, the microstructure of Cu elements of Zn-10Al matrix alloy melting characteristics, wetting properties, and the mechanical properties were studied by using vacuum furnace VF-1600M, metallographic microscope, SHIMADZU AG-125KN precision universal material testing machine. The results show that with the increase of the Cu content, the melting point of the solder decreases first and then increases. When the copper content is 4% (mass fraction), the melting point of the solder is the lowest. When the copper content is 5%, the wetting property is good, the grain of the solder is fine, and the tensile strength is the highest. When the copper content is continued to increase, the wettability of the solder is improved, the grain size becomes coarser, and the tensile strength decreases. Secondly, the effect of the addition amount of Sn elements on the properties of Zn-10Al-5Cu solder was also studied. The results show that the tensile strength is excellent, the melting temperature of the solder is decreased, and the wetting property of the solder is good when the amount of Sn addition is 3%. When the Sn content increases further, the wettability of solder alloy becomes poor, which does little spread. The obtained Zn-10Al-5Cu-3Sn is an excellent aluminum / copper brazing filler metal.