Thermodynamic assessment of the quaternary Cr–Fe–H–Zr system

Abstract

The thermodynamic assessments of the two ternary Cr–H–Zr and Fe–H–Zr systems are carried out using the CALPHAD approach. The hydrogenation properties of all the intermetallic compounds of these two systems are assessed. The formation enthalpies of the E1a-Zr₃FeH₇ and $C16$-Zr₂FeH₅ hydrides are evaluated by DFT calculations. The Pressure-Composition-Temperature diagrams of the Zr(Cr_xFe_1-x)₂ (0.4 < x < 1.1) of the C14 Laves phase are optimized. The calculations and optimization are carried out under para-equilibrium conditions in which the complete system was treated like a pseudo-binary system.