Experimental study and thermodynamic assessment of the Zn-Fe-Ni system

The Zn-rich corner of the Zn-Fe-Ni system was experimentally determined. It was found that the T phase, which was believed previously to be an extension of the binary Γ1 phase in the Zn-Fe system, is a true ternary compound. The composition range of this phase has been determined in this study. Based on the results of the assessments of the Zn-Fe and Zn-Ni systems carried out by the authors and using information on the Fe-Ni system available in the open literature, a preliminary assessment of the Zn-Fe-Ni system was carried out. A two-sublattice model (Fe,Ni,Zn)Zn5 was used to describe the ternary T phase. The calculated phase boundaries in the Zn-rich corner are in good agreement with experimental results. However, reproduction of the complex homogeneity range of the ternary T phase has proven challenging.