Experimental study and thermodynamic modelling of the ternary system Fe-Ni-Si with re-modelling of the constituent binary systems

The present paper reports on the thermodynamic modelling of the complete ternary Fe-Ni-Si system based on key experimental results and information reported in literature. The key experiments were performed to verify phases and phase fractions in selected ternary Fe-Ni-Si alloys using samples in the as-cast state as well as annealed samples. Chemical compositions of the samples were analysed by Energy Dispersive X-Ray Spectroscopy. Microstructure characterization was performed by Scanning Electron Microscopy and Electron Backscatter Diffraction techniques. Phase transformation temperatures were determined by Differential Scanning Calorimetry operated in the Differential Thermal Analysis mode. Calculations per-formed using proposed thermodynamic description reproduce experimental data well, including data from available literature. In particular, the Fe-rich corner of the Fe-Ni-Si system has been modelled in detail, with emphasis on the A2 and B2 phase fields. The developed ternary database was used to compute phase diagrams and thermodynamic properties of the constituent binary systems as well as selected isothermal and isopleth sections. Due comparison with commercially available and previously modelled thermo-dynamic descriptions is presented and discussed. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This paper presents the thermodynamic modeling of the complete ternary Fe-Ni-Si system based on experimental results and literature information. Key experiments were conducted to verify the phases and phase fractions in Fe-Ni-Si alloys, and the chemical compositions were analyzed. The modeling results match well with the experimental data, especially for the Fe-rich corner of the system. The ternary database developed in this study provides valuable information for phase diagrams and thermodynamic properties.