Cu,Ni对Sn-Zn-Al无铅焊料组织和性能的影响

Effect of Cu and Ni on microstructure and properties of Sn-Zn-Al lead-free solders

为了提高Sn-Zn系无铅焊料的性能,通过微合金化的方法得到了Sn-Zn-Al-Cu,Sn-Zn-Al-Ni四元无铅焊料.首先采用润湿平衡法对合金在铜片上的润湿力和润湿时间进行了测试,然后采用比色分析的方法直观比较了焊料的抗氧化性,最后测试了焊料的力学性能并对其微观组织进行了分析.结果表明:Cu和Ni的加入使得Sn-Zn-Al合金的润湿性有所提高,同时对抗氧化性无明显影响;微量Cu,Ni的加入使得组织中的粗大针状富Zn相细化和减少,并出现了新的含铜和含镍增强相,在强度提高的同时,塑性略有降低.

In order to improve the performance of Sn-Zn solders, new Sn-Zn solders were prepared by doping small amounts of Cu or Ni into Sn-Zn-A1 ternary alloys. A wetting balance method was utilized to measure the wetting force and wetting time of the solders on Cu substrate. By using the colorimetric analysis, the oxidation resistance of the solders was evaluated. Finally the mechanical property was tested and the microstructure was investigated. The results show that the additions of Cu and Ni into Sn-Zn-AI solders improves the wettability while it has no obvious effect on oxidation resistance. Minute additions of copper and nickel cause the decrease in the needle-like primary Zn-rich phase and the appearance of Cu-Zn or Ni-Zn intermetallic compound, which results in increments of tensile strength and a little deterioration of elongation.