Thermodynamic modelling of the Fe–Sn–Zr system based on new experiments and first-principles calculations.

The Fe–Sn–Zr system has been studied by first principles calculation and modelled with the Calphad method using the literature and new experimental data. The work includes a revision of Fe–Sn and Fe–Zr systems. Our experimental study has confirmed that the W 5 Si 3 phase (stoichiometry Zr 5 Sn 2,3 Fe 0,7) is stable at 1350 °C but also down to 1000 °C. Moreover, the crystal structure of the X " phase has been determined. The formation enthalpies of all the ordered configurations of the C 15, C 16, C 36, E 1a phases and the stoichiometric Fe 5 Sn 3 , Fe 3 Sn 2 , FeSn, FeSn 2, Fe 23 Zr 6 , FeSn 2 Zr 6 (θ), Fe 36.36 Sn 36.36 Zr 27.27 (N) et Fe 14.39 Sn 43.47 Zr 39.13 (X ″) compounds have been calculated using the Density Functional Theory (DFT). The mixing enthalpies of the A 1, A 2 and A 3 binary solid solutions have been calculated using the Special Quasirandom Structures (SQS) and DFT calculation. From these new experimental and calculated data, new thermodynamic assessments are proposed for Fe–Sn, Fe–Zr and Fe–Sn–Zr systems. • New experiments are provided for Fe–Sn–Zr system. • The structure of X″ phase has been determined. • a complete Calphad description of Fe–Sn–Zr system is given for the first time. • New thermodynamic assessments are provided for Fe–Sn and Fe–Zr systems. [ABSTRACT FROM AUTHOR]