Thermodynamic modeling of the Mg-Pu and Cu-Pu systems

The thermodynamic assessment of the Mg-Pu and Cu-Pu systems was carried out by using the calculation of phase diagrams (CALPHAD) method on the basis of experimental data including thermodynamic properties and phase equilibria. The Gibbs free energies of the liquid, fcc, hcp, αPu, βPu, γPu, δPu, δ′Pu, and εPu phases were described by the subregular solution model with a Redlich-Kister equation, and those of the intermetallic compounds in the Mg-Pu and Cu-Pu binary systems were described by the sublattice model. A consistent set of thermodynamic parameters were derived for describing the Gibbs free energies of solution phases and intermetallic compounds in the Mg-Pu and Cu-Pu binary systems. An agreement between the calculated results and experimental data is obtained.