First principle energies of binary and ternary phases of the Fe–Nb–Ni–Cr system

We present first principles enthalpies of formation and lattice parameters of iron, nickel, chromium and niobium alloys. Some of these results have been partially used in a recent assessment of the Fe–Ni–Cr–Nb quaternary phase diagram. Emphasis has been put on the fcc (A1) and bcc (A2) unary structures, the X3Y -D022,-L12,-D03,-D0a,X2Y -C14(MgZn2),-C15(MgCu2) and -C36 (MgNi2) Laves and X7Y 6-D85 (μμ) binary phases, and the X8Y 4Z18-D8b (σσ) ternary phase. We employed the state of the art to compute their properties by means of the DFT (PBE functional and PAW pseudo potentials). A comparison with experimental and theoretical data is also provided.

► Ni base alloys are used in the aeronautic and nuclear industries.
► First principles study of the structural and formation energies of the main unary and binary phases and one ternary phase of the Ni–Nb–Cr–Fe system.
► Good agreement between DFT simulations and experimental data.
► The formation energies calcuclated could help in the assessment of the phase diagrams containing Ni–Nb–Fe–Cr systems.