Structural Features and Solid-Solution Hardening of High-Entropy CrMnFeCoNi Alloy

Abstract

The phase composition, microstructure, and mechanical properties of the single-phase CrMnFeCoNi high-entropy alloy with fcc lattice produced by vacuum argon-arc melting are studied. The alloy solid-solution hardening mechanism is analyzed. It is established that the abnormally high athermic solid-solution hardening of the alloy is due to the variation in the Burgers vector along the dislocation line and to the presence of its component perpendicular to the slip plane. The activation energy of dislocation motion and activation volume are calculated. It is shown that the activation energy of dislocation motion is close to the activation energy of pure metals with the fcc lattice, and the activation volume is significantly reduced as compared to pure metals because picosized distortions grow in the crystal lattice of the multicomponent alloy. The ratio of hardness and yield stress for this alloy is examined.