Thermodynamic modelling of phase equilibria in systems for perspective lead-free solders represents first necessary step for development of new lead-free soldering materials. In our case the system Ag-In-Sb was chosen.
The theoretical predictions of phase equilibria in this system were compared with experimental data. The first step performed in this work included testing and verification of literature data for phase equilibria in 3 binary systems (Ag-In, Ag-Sb, In-Sb) [1],[2],[3]. The Thermo-Calc program was used for thermodynamic calculations.
Ternary system was not studied experimentally yet. Therefore the predictions of isothermal cross sections of ternary phase diagram at 200°C and at 500°C in this system were calculated on the basis of binary thermodynamic data only. These predictions were compared with phase equilibrium data, obtained experimentally. For this purpose, several samples of ternary alloys were prepared and annealed in evacuated silica capsule at 200ºC and at 500°C. Resulting alloys were analysed by Differential thermal analysis (DTA) and scanning electron microscope (SEM) analysis. An attempt to optimise thermodynamic parameters was made.
This work is part of COST Action 531 and is supported by the COST projects Nos. OC 531.001 and OC 531.002 of Ministry of Education of Czech Republic.
Literature:
[1] C.-S.Oh, J.-H. Shim, B.-J. Lee and D.N. Lee, J. Alloys Comp. 238, 155-166 (1996)
[2] Y. Cui, S. Ishihara, X. J. Liu, I. Ohnuma, R. Kainuma, H. Ohtani, K. Ishida:
Mat. Trans. 43, 1879 (2002)
[3] Z.Moser, W. Gasior, J. Pstrus, W. Zakulski, I.Ohnuma, X. J. Liu, Y. Inohana, K. Ishida: J. Electron. Mater. 30, 1120 (2001)
E-mail: veronika.buchtova@email.cz