Hydrogen storage properties of Zr-based multicomponent alloys with C14-Laves phase structure derived from the Zr-Cr-Mn-Fe-Ni system

Author(s)

Andrade, Gaspar ; Silva, Bruno Hessel ; Zepon, Guilherme ; Floriano, Ricardo

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL OF HYDROGEN ENERGY; v. 51, p. 9-pg., 2023-12-15.

Abstract

This study focused on assessing the crystal structure and hydrogen storage properties of two multicomponent alloys having the Zr33(CrMnFeNi)67 and Zr33Cr22Mn15Fe25Ni5 compositions. Both alloys were designed by thermodynamic calculations derived from the TiZrCrMnFeNi system after removing the titanium element from the original composition and keeping the high fraction of zirconium to explore new Zr-based compositions with a strong tendency to crystallize as a C14 Laves phase. The arc-melted Zr-based alloys exhibited a significant presence of C14 Laves phases and small amounts of NiZr intermetallic phase. Hydrogen storage properties investigated through pressure-composition-temperature (PCT) absorption and desorption isotherms revealed that the Zr33Cr22Mn15Fe25Ni5 alloy could absorb 1.8% (H/M = 1.2) of hydrogen with fast kinetics at room temperature after a simple heat activation, while the Zr33(CrMnFeNi)67 alloy could reversibly absorb 1.6% (H/M = 1) with equally fast kinetics. Zr-rich alloys exhibited a low hydrogen equilibrium pressure in the PCT isotherms. After full hydrogenation at room temperature, the initial metallic C14 Laves phases were converted to the respective Laves phase hydrides in both cases. Under cycling, the fractions of the secondary NiZr and the C14 phase change as the samples become more activated. The microstructural analysis, before and after the cycling, showed a very homogeneous microstructure and good distribution of the elements in both alloys. (AU)

• FAPESP's process: 22/01351-0 - Study of the mechanisms of metal-hydrogen reactions in multicomponent alloys with C14 - hexagonal laves phases
• Grantee: Ricardo Floriano
• Support Opportunities: Regular Research Grants