Fe–Ni many-body potential for metallurgical applications

A many-body interatomic potential for the Fe–Ni system is fitted, capable of both the ferritic and austenitic phase. The Fe–Ni system exhibits stable ordered intermetallic phases, namely, L10 FeNi and L12 FeNi3, are key issues to be tackled when creating a Fe–Ni potential consistent thermodynamics. A procedure, based on a rigid lattice Ising model the theory of correlation functions space, is developed to address all the that are possible ground states of the system. While controlling ground states of the system, the mixing enthalpy and defect properties fitted. Both bcc and fcc defect properties are compared with density theory calculations and other potentials found in the literature., the potential is thermodynamically validated by constructing the alloy diagram. It is shown that the experimental phase diagram is reproduced well and that our potential gives a globally improved description of Fe–Ni system in the whole concentration range with respect to the potentials in the literature.