High pressure solidification of alloying substitution and promotion of hydrogen storage properties in AB2-type Y-Zr-Ti-Fe based alloys

Metastable phase has great potential in searching hydrogen storage alloys. In this work, high pressure solidification has been successfully used to realize the supersaturation of Ti in YFe2 based C15 Laves phase to obtain a metastable Y0.7Zr0.24Ti0.06Fe2 alloy. The segregation of Ti, Y, Zr and related multi-phase formation were substantially suppressed and the obtained HPS alloy contained a primary C15 phase(C15–1) and a secondary C15 phase(C15–2) with 77.1% and 22.9% of the total content, respectively. Meanwhile, the hydrogen absorption and desorption capacities increased substantially. This study proves that the combination of high-pressure solidification and alloying is a very effective method for exploring new hydrogen storage materials with metastable structure and high performance.