Stabilization of Equiatomic Solutions Due to High-Entropy Effect

The stability of solid-solution phases in FCC and BCC lattices was examined in multi-component alloys based on the CALPHAD technique using the compound energy formalism and regular solution model. From the thermodynamic calculations, it was found in ternary systems that the single solid-solution phase became stable around the equiatomic composition where the configurational entropy was the largest value. The transition temperatures decreased with the increasing number of elements in the system. The A1/L10 transition temperature was affected by the stoichiometric compositions of the ordered phases existing at the equiatomic composition, whereas it was not significant for the A2/B2 transition in the two-sublattice model. The single solid-solution phase region at equiatomic compositions was affected by variations in the interaction parameters. In multi-component systems, the variations were averaged with increasing the number of elements in the system. This suggests that high-entropy alloys can afford a variety of elements.