Thermodynamic Analysis of Phase Equilibria in the Mg–Al–Ho Ternary System

Abstract

A thermodynamic analysis of phase equilibria in the MgAlHo ternary system has been carried out with special emphasis on the metastable phase separation of the hexagonal close-packed (hcp) phase. In this study, the Gibbs free energy of mixing of the hcp phase was evaluated using first-principles calculations combined with the cluster variation method (CVM), and the obtained results as well as the available experimental data were introduced into the analysis. The calculated results enabled the reproduction of experimental results on both the phase equilibria and the thermodynamic properties obtained from the first-principles calculations and the CVM. In addition, the calculations indicated a tendency for metastable two-phase separation in the hcp phase between the Mg-rich corner and the AlHo binary side, which was similar to the MgYZn ternary system shown in our previous work.

Thermodynamic Properties of Binary Al–Pr Alloys

“…This difference is much higher than the experimental errors and the distinction between various elements in the Al-Ln series. In addition, there are new papers [34][35][36][37][38][39][40] for Al-Ln systems focusing on the simulation of their thermodynamic properties, differing largely from [10] as well.…”