Effects of Ti substitution by Zr, on the microstructure and hydrogen storage properties OF Ti2-xZrxCrV (x = 0.5, 1, 1.5, 2) alloys.

The effect of the substitution of Ti by Zr on the crystal structure, microstructure, and first hydrogenation behavior of Ti2-xZrxCrV where X = 0.5, 1.0, 1.5, and 2.0 have been investigated. The samples were synthesized by arc-melting and characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The hydrogenation capacity was measured using a home-made Sieverts apparatus. Pure-Ti2CrV crystallizes in a body-centered cubic structure (BCC). Substitution of Ti by Zr leads to the appearance of a secondary phase, namely a C15 Laves phase for the Ti-containing samples, and C15 Laves phase plus a Zr-rich phase for the X = 2.0 sample. The substitution of Ti by Zr increased the lattice parameters in both phases for all samples. Increasing Zr content made the first hydrogenation faster but reduced the hydrogen capacity.

Effect of Zr3Fe addition on hydrogen storage behaviour of Ti2CrV alloys.

In this work, the hydrogen storage behavior of Ti2CrV + X wt.% Zr3Fe, where X = 2, 4, 6, 8 and 10 was investigated. The synthesis of all samples was carried out through arc-melting, followed by comprehensive characterization using X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The pure-Ti2CrV as-cast sample presented a single-phase microstructure. However, the addition of the Zr3Fe led to a remarkable transformation, resulting in the appearance of a Zr-rich secondary phase. It was found that the first hydrogenation is improved with the addition of at least 6 wt% of Zr3Fe, avoiding any preheating of the sample. These samples achieved their maximum capacity in approximately 10 min at room temperature. The maximum capacity recorded was 4.2 wt% H for the sample with X = 6 wt% Zr3Fe, while for X = 8 and 10 wt% Zr3Fe, the capacity recorded was 4.1 wt% and 4.0 wt%, respectively.