Short-Range Order Formed in an Equiatomic CoNiCrFeMn Alloy during Annealing. Atomistic MD/MC Simulation

The formation of a short-range order in an equiatomic high-entropy alloy (HEA) CoNiCrFeMn during annealing at moderate temperatures is studied by atomistic MD/MC simulation, including the exchange of atoms in the Monte Carlo (MC) scheme and relaxation of their positions by molecular dynamics (MD) simulation. Two types of chemical short-range order (CSRO) regions are found to form during annealing. The first type is mainly represented by Fe–Co atoms, and the second, by Cr-rich regions with Ni and Mn atoms at their boundaries. The short-range order formation is shown to include several stages, the sequence of which is determined by the Cr–Cr, Fe–Co, and Ni–Mn interactions.