The Sn-Bi-Ag system is an important ternary system for electronic products, and this study investigates its phase equilibria and solidification behavior. Sn-Bi-Ag alloys were prepared and equilibrated at 210 °C and 400 °C, and their equilibrium phases were determined. Thermodynamic descriptions of the ternary Sn-Bi-Ag system are developed from the results determined in this study and those available in the literature. Isothermal sections and liquidus projection are then calculated using the determined Sn-Bi-Ag thermodynamic descriptions. Solidified microstructures of three Sn-Bi-Ag alloys are examined. It is found that the solidification paths cut through the monovariant line, instead of following the monovariant line as expected.
- Phase equilibria