Thermodynamic description of the Al–Fe–Ni system over the whole composition and temperature ranges: Modeling coupled with key experiment

This paper performs an extensive investigation for the complex Al–Fe–Ni system via key experiments and thermodynamic modeling. 12 decisive alloys are prepared with a desire to provide accurate phase relationships needed for the refinement of this ternary phase diagram. The order/disorder transitions between disordered BCC_A2 and ordered BCC_B2 phases as well as between disordered FCC_A1 and ordered L12 phases are described as a two-sublattice model. The calculations indicate that the disordered and ordered phases can be described with a single equation. A self-consistent thermodynamic description of the Al–Fe–Ni system is obtained by considering the huge amount of experimental data from the literature and the present work. Most of the experimental data can be satisfactorily reproduced by the present modeling. The complete liquidus projection and reaction scheme are also presented.