Structure and Properties of TiCrFeNiC High Entropy Alloy Produced by Powder Metallurgy

A feature of this class of materials is the unique combination of physical and mechanical characteristics both at room and at elevated temperatures. It is believed that high mechanical properties of HEAs are provided mainly due to the fact that the presence of dissimilar atoms of elements with different electronic structures, size and thermodynamic properties in the crystal lattice of the solid solution of substitution leads to its significant distortion and slow diffusion of atoms in a multicomponent elemental matrix. This contributes to significant solid solution hardening and thermodynamic stability of properties, provides increased thermal stability of the phase composition and structural state, and, consequently, high alloy properties hardness, strength, wear resistance, oxidation resistance, etc. The high entropy of mixing elements in the alloys causes the Gibbs free energy to be minimized and leads to the predominant formation of solid solutions with BCC, FCC or FCC + BCC structure. The phases formed on the basis of solid solutions are more stable than intermetallic compounds or other complex ordered structures [1,2].