Isothermal section of ternary Sn-Zn-Ni phase equilibria at 250 °C

Ternary Sn–Zn–Ni alloys were prepared and equilibrated at 250 °C for 4–15 weeks. The phases formed in these equilibrated alloys were determined experimentally. The isothermal section of Sn–Zn–Ni system was constructed, based on the phase diagrams of the three constituent binary systems and the ternary phase equilibria data, determined in this study and referenced in literatures. 12 single-phase regions were identified in the Sn–Zn–Ni ternary system at 250 °C, including the three ternary compounds, δ,τ1 and τ2. There were 13 ternary phase regions and 23 binary phase regions in the 250 °C Sn–Zn–Ni isothermal section. The solubility of Zn in the binary Sn–Ni compounds is significant, and is 15.1% (mole fraction) in the Ni3Sn phase.