High-temperature oxidation behavior of Sn-8Zn-3Bi-P and its effect on properties

The effect of alloying P on oxidation behavior of the liquid Sn-8Zn-3Bi lead-free solder at 250℃ was investigated by thermogravimetry experiment.The effect mechanism of P on the oxidation was discussed by scanning electronic microscopy(SEM) and auger electronic spectroscopy (AES)in experiments.Properties were compared between before after oxidation to explore the effect on solders' other properties.The results indicate that P can improve the oxidation resistance of Sn-8Zn-3Bi obviously.P was oxidized which is prior to Zn.A oxide film consisting of P₄O₆ which was tend to volatilize formed on the surface of the solder.The over-all properties of the solder is best with the addition of 0.2wt.%P.