Evolution of the Phase and Hydrogen Storage Properties of New-Type VTiCrFeMn High-Entropy Alloy Prepared via Mechanical Alloying

Abstract

High-entropy alloys (HEAs) have ample space for composition design, so finding an ideal hydrogen storage material is a great challenge. This work used the atomic radius difference, valence electron concentration, entropy, enthalpy, and new design parameters to develop a new-type alloy with a BCC structure. The V₃₅Ti₂₅Cr₂₀Fe₁₀Mn₁₀ alloy was selected by semi-empirical formula calculation, subsequently, the alloy was successfully synthesized by mechanical alloying, and hydrogen storage properties were evaluated. The activated sample shows an excellent kinetic performance of hydrogen absorption, but its maximum hydrogen storage capacity is only about 0.34 wt.%. The results of the PCI test show that the hydrogen absorption way may be composed of the H-solid solution in the alloy and the formation of a few hydrides, which determines the hydrogen storage capacity. Significantly, the design method reported in this paper can meet the composition design of most HEAs, which has a broad application prospect.

Keywords:

• High-entropy alloy
• alloy design
• hydrogen absorption properties
• mechanical alloying
• kinetic performance

Additional information

Funding

This work was financially supported by the Basic Research Project of Yunnan Province (Nos. 202021AS070049 and 202102AB080004).