Thermodynamic assessments of the Sc–M (M: Ag, B and Th) systems

The phase diagrams and thermodynamic properties in the Sc–M (M: Ag, B and Th) binary systems have been assessed by using the CALPHAD (Calculation of Phase Diagrams) method on the basis of the experimental data including the thermodynamic properties and phase equilibria. The Gibbs free energies of the liquid, bcc, fcc, and hcp phases were described by the subregular solution model with the Redlich–Kister equation, and those of the intermetallic compounds (Ag4Sc, Ag2Sc, AgSc, ScB2 and ScB12) in these three binary systems were described by the sublattice model. The thermodynamic parameters of the Sc–M (M: Ag, B and Th) binary systems were obtained, and an agreement between the calculated results and experimental data was obtained in each binary system.