Thermodynamic Reassessment of the Cu-Ni-Sn System

Adéla Zemanová and Aleš Kroupa

Institute of Physics of MaterialsAcademy of Sciences of Czech Republic Žizkova 22, 616 62 Brno Czech Republic

 The Cu-Ni Binary System

FCC_A1+FCC_A1

S. an Mey: CALPHAD, Vol. 16 (1992), p. 255

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(D03)/(A2) two-phase equilibrium

H.S. Liu, J. Wang and Z.P. Jin: CALPHAD, Vol. 28 (2004), p. 363

 The Ni-Sn Binary System

• Ni3Sn phase (D03 structure) - has been modelled as BCC_A2 phase in the COST 531 database for compatibility with Cu-Sn system

• Ni3Sn2 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

 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 Ni3Sn- phase was modelled as BCC_A2 to correspond

to the model used in Cu-Sn system

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

The calculated isothermal section at 600 °C together with experimental data [*]

[*] H. Flandorfer and H. Ipser: private communication

Sn

NiCu

L

BCC_A2

Ni Sn3 2

Ni Sn_LT3

FCC_A1

Cu Ni Sn3 27 10

Cu Sn3

Ni Sn3 4

Cu Sn10 3

full symbols – full agreement betweenthe calculation and experimentally obtained phase equilibria blank symbols – disagreement of calculation with experiment

Exp. results: - single phase equilibrium; - two-phase equilibrium;

- three-phase equilibrium.

Sn

NiCu

L

FCC_A1

Ni Sn3 2

Ni Sn_LT3

BCC_A2

[*] C.H. Wang and S.W. Chen: Mater. Trans. A., Vol. 34A (2003), p. 2281

full symbols – full agreement betweenthe calculation and experimentally obtained phase equilibria blank symbols – 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 [*]

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

FCC_A1

L

BCC_A2

BCC_A2+Cu Sn3

2 wt% Ni

15 wt% Ni

L

FCC_A1

BC

C_

A2

4 wt% Ni

FCC_A1

BCC_A2

FCC_A1+Cu Sn3

L

J. Veszelka: Mitt. Berg-Hüttemänn (Abt. Ung. Hochschule Berg-Forstw., Sopron,1932).

The calculated isopleth at xSn = 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

x = 0.25Sn L

BCC_A2

[12][ ]13

Cu Sn+Ni Sn

3

3 2 Cu Sn+Ni Sn+BCC_A2

3 3 2

BCC_A2+FCC_A1

BCC_A2+Ni Sn_LT3

Cu Ni Sn+FCC_A1+Ni Sn_LT

3 27 10

3

Cu Sn+BCC_A2(very narrow region)

3

• the high temperature form of Ni3Sn 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

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.