Isothermal Section of the Sn-Fe-Zn Ternary System at 270°C

Abstract

With a relatively low liquidus temperature, the eutectic Sn-Zn alloy is suitable replacement for conventional eutectic Sn-Pb solder in the electronic industry. One of the most important materials as a lead-frame is Fe-42Ni alloy (Alloy 42) in the microelectronic packaging. The Sn-Fe-Zn ternary phase diagram is a powerful and useful tool to understand the interfacial reactions between Sn-Zn alloy and Alloy 42 substrate (Fe-rich alloy). The isothermal section of the Sn-Fe-Zn ternary system was experimentally investigated at 270oC in this study. Ternary Sn-Fe-Zn alloys were prepared and annealed at 270 oC to determine the isothermal section of the Sn-Fe-Zn ternary system. The experimental results revealed that no ternary intermetallic compound was formed, and noticeable Zn solubility was observed in the FeSn2 phase. The isothermal section of the Sn-Fe-Zn ternary system consists of nine single-phase areas, thirteen two-phase areas, and seven tie-triangles at 270 oC