Investigation on Ti–Zr–Cr–Fe–V based alloys for metal hydride hydrogen compressor at moderate working temperatures

Abstract Ti0.85Zr0.17Cr1.2-xFe0.8Vx (x = 0–0.2), Ti0.85Zr0.17Cr1.2-yFe0.7+yV0.1 (y = 0–0.25) and Ti0.87-zZr0.15+zCr0.95Fe0.95V0.1 (z = 0–0.04) alloys for metal hydride hydrogen compressor at moderate working temperatures were prepared by induction levitation melting. Their microstructures and hydrogen storage properties were systematically investigated. The results show that all Ti–Zr–Cr–Fe–V based alloys have a single C14 Laves phase structure. As the V content in the Ti0.85Zr0.17Cr1.2-xFe0.8Vx (x = 0–0.2) alloys increases, better activation kinetics and larger hydrogen storage capacity are achieved, while the plateau pressure decreases and the plateau slope factor increases. Similarly, the hydrogen storage capacity, the plateau pressure and the plateau slope factor of the Ti0.87-zZr0.15+zCr0.95Fe0.95V0.1 (z = 0–0.04) alloys vary identically with Zr content increasing. Conversely, these three properties vary oppositely with increasing Fe content in the Ti0.85Zr0.17Cr1.2-yFe0.7+yV0.1 (y = 0–0.25) alloys. Among the studied alloys, Ti0.85Zr0.17Cr0.95Fe0.95V0.1 possesses the best overall properties for the designed moderate hydrogen compression application.