Effect of silicon addition on mechanical and electrical properties of Sn–Zn based alloys rapidly quenched from melt

In the present study, the effect of Si additions (0.1–0.5 wt.%) on mechanical and electrical properties of Sn–12Zn–3Bi based alloys was studied and analyzed. The investigation indicates that the mechanical properties of quaternary alloy Sn–12Zn–3Bi–0.5Si are higher than that of binary Sn–12Zn and ternary Sn–12Zn–3Bi melt spun-alloys. The addition of silicon to the Sn–12Zn–3Bi ternary system improves the electrical resistivity of the alloy and lowers the melting temperature. The Sn–12Zn–3Bi–0.3Si alloy has a melting point around 195 °C. Electrical resistivity of Sn–Zn–Bi–Si solder alloys, 9–14 μΩ cm, is much lower than that of Sn–37Pb solder. Test results indicate that adding small amount of Si can evidently improve the solderibility, mechanical, creep resistance, melting point and electrical properties of the binary Sn–12Zn and ternary Sn–12Zn–3Bi alloys. The change in mechanical and electrical properties is discussed based on the microstructural observations.