Effects of Zn, Zn-Al and Zn-P Additions on the Tensile Properties of Sn-Bi Solder

摘要

Effects of Zn, Zn-Al and Zn-P additions on melting points, microstructures, tensile properties, and oxidation behaviors of Sn-40 Bi lead-free solder were investigated. The experimental results show that the addition of these three types of elements can refine the microstructures and improve the ultimate tensile strength(UTS) of solder alloys. The fractographic analysis illustrates that ductile fracture is the dominant failure mode in tensile tests of Sn-40Bi-2Zn(SBZ)and Sn-40Bi-2Zn-0.005Al(SBZA) specimens, while brittle fracture is the controlled manner in Sn-40Bi-2Zn-0.005P(SBZP) and Sn-58 Bi solders. XPS analysis indicates that trace amounts of both Al and P additives in solder can improve the antioxidant capacity, whereas only the additive of Al in solder can reduce the thickness of oxidation film.