First-principles studies of behavior of hydrogen and mechanical properties of TiCrTaV high-entropy alloys

Abstract

This study investigates the dissolution and diffusion of H atom in TiCrTaV of two body-centered cubic (BCC) high-entropy alloys and their effects on the mechanical properties and electronic structure of the alloys by first-principles calculations. Results show that the solution energy of H atom and local lattice distortion vary depending on the local environment. Meanwhile, the site occupancy of H atoms in tetrahedral interstitials are slightly advantageous in the two structures. Diffusion of H also presents a sluggish effect. The dramatic increases and decreases of diffusion barrier disrupted the periodicity and symmetry of H diffusion in the two BCC structures, thereby slowing down the H accumulation. After hydrogenation, TiCrTaV high-entropy alloys (HEAs) still maintain resistance to deformation, indicating that they are the potential candidate structural materials for fusion reactors. Our investigation indicates that this low-activation HEA may exhibit promising irradiation resistance due to its special H behavior.