Grain boundary structure in high-entropy alloys

We report atomistic simulation studies of grain boundary structure in a high-entropy FCC alloy. The simulations are based on empirical interatomic potentials and use massively parallel molecular dynamics techniques at the atomistic level to study the local structure. The studies address a series of pure tilt grain boundaries with random misorientations around the [110] crystallographic axis. We study the relaxed structures using various models and visualization techniques, including analyzing the dislocation content of the boundary region. A main focus is the role that the local composition in the random alloy plays in the structure and energy of the boundaries. This is performed by comparing the structures obtained for the complex random alloy with a corresponding “average atom” material that has the same average properties, but no local randomness. The implications for the overall properties of high-entropy alloys are discussed.