1. Thermodynamic Reassessment of the Cu-Ni-Sn System Adéla Zemanová and Aleš Kroupa Institute of Physics of Materials Academy of Sciences of Czech Republic Žizkova 22, 616 62 Brno Czech Republic

2. The Cu-Ni Binary System FCC_A1+ FCC_A1 S. an Mey: CALPHAD, Vol. 16 (1992), p. 255

3. X.J. Liu, H.S. Liu, I. Ohnuma, R. Kainuma, K. Ishida, S. Itabashi, K. Kameda and K.Yamaguchi: J. Electron. Mater., Vol. 30 (2001), p. 1093 The Cu-Sn Binary System J. Miettinen: CALPHAD, Vol. 27 (2003), p. 309 FCC_A1 and LIQUID phase data were modified to take into account new experimental data obtained in the scope of COST 531 Action γ(D0 3 )/  (A2) two-phase equilibrium

4. H.S. Liu, J. Wang and Z.P. Jin: CALPHAD, Vol. 28 (2004), p. 363 The Ni-Sn Binary System Ni 3 Sn phase (D0 3 structure) - has been modelled as BCC_A2 phase in the COST 531 database for compatibility with Cu-Sn system Ni 3 Sn 2 phase – remodelled to make it compatible with the Au-Ni-Sn assessment - 3-sublattice model: (Ni,Sn) 0.5 (Ni) 0.25 (Ni) 0.25

5. The reassessment of the Cu-Ni-Sn Ternary System based on the work - Miettinen [J. Miettinen: CALPHAD, Vol. 27 (2003), p. 309] - Wang et. al. [C.H. Wang and S.W. Chen: Mater. Trans. A., Vol. 34A (2003), p. 2281] - Pool [ M.J. Pool, I. Arpshofen, B. Predel and E. Schultheiss: Z. Metallkd., Vol. 70 (1979), p. 656 ] - experimental results obtained as part of the COST 531 programme Why the new reassessment ? 1.different unary data [Version 4.4 of the SGTE Unary database] 2.different descriptions of the relevant binary systems 3.the high-temperature Ni 3 Sn-  phase was modelled as BCC_A2 to correspond to the model used in Cu-Sn system

6. The calculated enthalpy of mixing in liquid Cu-Ni-Sn alloys at 1580 K together with experimental data points [*] [*] M.J. Pool, I. Arpshofen, B. Predel and E. Schultheiss: Z. Metallkd., Vol. 70 (1979), p. 656

7. The calculated isothermal section at 600 °C together with experimental data [*] [*] H. Flandorfer and H. Ipser: private communication full symbols – full agreement between the calculation and experimentally obtained phase equilibria blank symbol s – disagreement of calculation with experiment Exp. results:  - single phase equilibrium;  - two-phase equilibrium;  - three-phase equilibrium.

8. [*] C.H. Wang and S.W. Chen: Mater. Trans. A., Vol. 34A (2003), p. 2281 full symbols – full agreement between the calculation and experimentally obtained phase equilibria blank symbol s – disagreement of calculation with experiment Exp. results:  - single phase equilibrium;  - two-phase equilibrium;  - three-phase equilibrium. The calculated isothermal section at 800 °C together with experimental data [*]

9. The calculated isopleths at 2, 4 and 15 wt% Ni in the copper-rich part of the Cu-Ni-Sn system together with experimental data  J. Veszelka: Mitt. Berg-Hüttemänn (Abt. Ung. Hochschule Berg-Forstw., Sopron,1932).

10. The calculated isopleth at x Sn = 0.25 in the Cu-Ni-Sn system together with experimental data points  E. Wachtel and E. Bayer: Z. Metallkd., Vol. 75 (1984), p. 205  J.S.L. Pak, K. Mukherjee, O.T. Inal and H.R. Pak: Mater. Sci. Eng., Vol. A117 (1989), p. 167

11. the high temperature form of Ni 3 Sn phase in the Ni-Sn binary system was remodelled as BCC_A2 for compatibility with Cu-Sn binary system very good agreement was reached with respect to the existing experimental data and previous description of this phase in binary system a thermodynamic description was optimized for the Cu-Ni-Sn ternary system by applying the experimentally measured mixing enthalpy in liquid and experimental phase equilibrium data from the literature the good agreement was obtained between calculated and experimental phase equilibria data and thermodynamic properties Conclusion

12. The authors are grateful to the Ministry of Education of the Czech Republic (Projects No. COST OC 531.002), and to the Academy of Sciences of the CR (project No. KJB 200410601) for financial support. Acknowledgement Thank you for your attention.