Thermodynamic properties of alloys of the Ni-Sc and Ni-Y systems

Partial and integral enthalpies of mixing for Ni-Y melts at 1775 K (0 < x Y < 0.34), 1850 K (0.72 < x Y < 1) and Ni-Sc at 1880 K (0 < x Sc < 0.35, 0.51 < x Sc < 1) are determined by means of calorimetry. Thermodynamic properties of liquid and solid alloys and phase diagrams of Ni-Sc(Y) systems in wide ranges of concentration and temperature are modeled using the ideal associated solution theory. It is found that the activities of components exhibit strong negative deviations from the Raoult’s law.