Thermodynamic assessments of the Sm-Zn and Nd-Zn systems

In order to develop the thermodynamic database of phase equilibria in the Mg-Zn base alloy system, the thermodynamic assessments of the Sm-Zn and Nd-Zn systems were carried out by using the calculation of phase diagrams (CALPHAD) method on the basis of the experimental data including thermodynamic properties and phase equilibria. Based on the available experimental data, Gibbs free energies of the solution phases (liquid, bcc, hcp, dhcp and rhomb_C19) were modeled by the subregular solution model with the Redlich-Kister formula, and those of the intermetallic compounds were described by the sublattice model. A consistent set of thermodynamic parameters has been derived for describing the Gibbs free energies of each solution phase and intermetallic compound in the Sm-Zn and Nd-Zn binary systems, respectively. An agreement between the present calculated results and experimental data is obtained.