Phase equilibria and thermodynamics of binary copper systems with 3d-metals.: VI.: Copper-nickel system

Thermodynamic evaluation of the Cu-Ni system within the CALPHAD approach is based on values of mixing enthalpies and activities of components in liquid and solid solutions, as well as parameters of phase transformations. The excess Gibbs free energy of phases is described by the following equations: Delta G(L, ex) = x(Ni)(1-x(Ni))(14259 + 0.45T) J/mole for liquid alloy and Delta G((Cu, Ni), ex) = x(Ni)(1-x(Ni)) x (6877.12 + 4.6T + (1-2x(Ni))(-2450.1 + 1.87T)) J/mole for fcc solution. For the Gibbs free energy of the (Cu, Ni) phase, the magnetic effect is described by thye Hillert-Jarl method. The thermodynamic model of the system generates a self-consistent description of all thermodynamic values and phase equilibria. The calculated binodale of fcc solid solution is in satisfactory agreement with experimental data. The critical point have coordinates 605 K and x(Ni) = 0.6