The mechanical properties of high entropy (-like) alloy Wx(TaTiVCr)1-x via first-principles calculations

Mechanical and electronic properties of high entropy (-like) alloys Wx(TaTiVCr)1-x (x = 0.30-0.67) with body centered cubic structure are investigated employing density function theory in combination with special quasi-random structure (SQS) model. With simultaneous addition of multi-principle alloying elements with smaller average of atomic radii, the lattice constants drop slightly, and structural stability is lowered due to the higher formation enthalpies. The calculated elastic stiffness constants and elastic moduli derived within the Voigt-Reuss-Hill approximation suggest the noticeable decrease of hardness and strength of the Wx(TaTiVCr)1-x (x = 0.30-0.67) alloys. Interestingly, ductility of Wx(TaTiVCr)1-x (x = 0.30-0.67) alloys is apparently increased, whereas elastic anisotropy is somewhat larger from several criterions. The further studied electronic structures show that bonding of Wx(TaTiVCr)1-x (x = 0.30-0.67) dominantly originates from the contributions of d electrons of constituent elements, WW bonding is stronger than WM (M = Ta, Ti, V, Cr) and MM interactions (M = Ta, Ti, V, Cr). With simultaneous addition of multi-principle alloying elements, values of DOSs at Fermi level are higher and the interplay between atoms is decreased, showing the lower stability. These results provide a guideline for further optimizing the composition and mechanical properties of tungsten alloy.