Thermodynamic Calculation Of Phase Equilibria In Sb-Sn-X(X=Au,Ag,Cu) Alloy Systems

Pb-Sn alloy solder is widely used in the electronics industry for its excellent performance and low cost,but factors such as environmental pollution,legal restrictions,and technological developments make it necessary to find new high-performance lead-free solders.The most promising lead-free solder to replace the Pb-Sn alloy solder is Sn-based alloy.In this study,the phase equilibria and phase transitions of the Sb-Sn-X(X=Au,Ag,Cu)ternary systems were investigated based on the experimental measurements of phase equilibria and thermodynamic properties,as well as the results of the Sb-Sn binary system optimized in this work,mainly as follows:(1)The phase transition temperatures of Sb-Sn alloys were determined using differential thermal analysis(DTA),the Sb-Sn binary system was reoptimized using the CALPHAD method,and the calculated phase diagrams and thermodynamic properties of the Sb-Sn system were in good agreement with the experimental data.A reasonably selfconsistent Au-Sb-Sn thermodynamic database was obtained based on the experimental results of liquids projection,isothermal sections,partial vertical sections reported in previous literature,and the calculated isothermal and vertical sections and property diagrams of the Au-Sb-Sn system were in good agreement with the experimental results.(2)Based on the experimental results of thermodynamic and phase equilibria experimental measurements and the results of the Sb-Sn binary system optimized in this work,the thermodynamic modeling of the Ag-Sb-Sn system was carried out using the phase diagram calculation CALPHAD method to evaluate the thermodynamic parameters of the stable phase in the Ag-Sb-Sn ternary system as well as the thermodynamic properties of the Ag-Sb-Sn ternary system.The liquids projection,isothermal and vertical sections were calculated and compared with available experimental results.The results show reasonable agreement with all available experimental data and similar or better agreement with previously calculated thermodynamic models.(3)Thermodynamic models for each phase in the Cu-Sb-Sn ternary system were evaluated and thermodynamic calculations were performed.The calculated results are in good agreement with the experimental results.The phase diagram calculation CALPHAD method was used to thermodynamically model the Cu-Sb-Sn system,and its liquids projection and isothermal section were calculated.A self-consistent Cu-Sb-Sn thermodynamic database was obtained based on the reproduction of isothermal sections,liquids projection,invariant reactions,and thermodynamic properties,indicating that the database can accurately describe the phase equilibria and thermodynamic properties of the Cu-Sb-Sn system.