Effects of alloying elements on the characteristics of Sn-Zn lead-free solder

Abstract

In this work, the effects of alloying elements, such as lanthanum, titanium, aluminum, and chromium, on the oxidation resistance, the wetting properties and the tensile properties of Sn-Zn based lead-free solder were studied. The results show that, under the condition of experiment, alloying additions of Al and Cr can significantly improve the oxidation resistance of Sn-9Zn solder, and Ti have a less effect. Further experiments show that the addition of Al worsens the wetting properties of Sn-9Zn solder, but Cr does not have unfavorable effect on the wetting properties and the melting point of Sn-9Zn solder. The effect of Cr alloying content on the oxidation resistance of Sn-9Zn solder was further studied, and the results indicate that increasing Cr content can enhance the oxidation resistance. To some extent the addition of Cr can improve the elongation of Sn-9Zn solder, but has a less effect on the tensile strength of that.