Formation Conditions and Properties of High-Entropy Alloys Creating σ-Phase

High-entropy alloys (HEA) based on the renewal of elements of the V–IX groups of the Periodic Table, which are capable of forming σ-phase with each other, are studied. The formation of the σ-phase in the range of electronic concentration of 6.7-8 el/at was monitored. The effect of electron concentration on the content of the σ-phase in HEA-containing elements forming the σ-phase in a two-component system is shown. The conditions for the formation of a single-phase structure of the σ-phase during crystallization of multicomponent HEA are determined. The limits of the existence of a 100% high-entropy phase are established and the influence of lattice parameters on their properties is revealed. A decrease in the size of the parameters c and an of the σ-phase leads to an increase in both the hardness and modulus of elasticity of alloys with a single-phase structure of the high-entropy σ-phase.