Microstructure and characteristics of soldered joint of high strength ZA alloy

The microstructure and characteristics,properties and phase composition of soldered joint were investigated by optical microscope, scanning electron microscope and X-ray diffraction. The results show that interactive crystallization exists in the interfacial region by using a new developed high strength soldering filler metal. It is complex that the phases in interfacial region.Both solid solution of Cd,Sn,Zn and small amounts of fine grained compounds of Mg₂Sn, MgZn are founded in the interfacial region. Solid solution could improve the strength and plasticity, and small amounts of fine grained compounds could strengthen the matrix which is beneficial to improve the joint strength. However, successive laminate of intermetallic compounds will result in embitterment and deteriorate the properties of the joint. The results also show that the properties and elongation percentage of the joint are higher than base material.