B2 ordering in body-centered-cubic AlNbTiV refractory high-entropy alloys
Fritz Körmann, Tatiana Kostiuchenko, Alexander V. Shapeev, Jörg Neugebauer
Abstract
The phase stability of a bcc AlNbTiV high-entropy alloy at elevated temperatures is studied using a combination of machine-learning interatomic potentials, first-principles calculations, and Monte Carlo simulations. The simulations reveal a B2 ordering below about 1700 K, mainly caused by a strong site preference of Al and Ti. A much weaker site preference for V and Nb is observed, strongly affecting the alloys total configurational entropy. The underlying mechanisms of the B2 phase stability as opposed to the random solid solution are discussed in terms of a high persisting configurational entropy of the B2 phase due to strong sublattice site disorder.
Topics & Concepts
Materials scienceConfiguration entropyHigh entropy alloysCubic crystal systemAlloyThermodynamicsMonte Carlo methodEntropy (arrow of time)Condensed matter physicsStatistical physicsMetallurgyPhysicsMathematicsStatisticsHigh Entropy Alloys StudiesMetal and Thin Film MechanicsHigh-Temperature Coating Behaviors