Influence of partial substitution of Mo for Cr on structure and hydrogen storage characteristics of non-stoichiometric Laves phase TiCrB0.9 alloy

The influence of the partial substitution of Mo for Cr on phase composition and hydrogen storage characteristics of non-stoichiometric Laves phase TiCrB0.9-based alloys is investigated by X-ray diffraction (XRD), pressure composition isotherm (PCT), and scanning electron microscopy (SEM) characterizations. XRD tests reveal that the phase composition of the alloys gradually changes from single TiB1.07CrB1.93 Laves phase to the co-existence of Laves phase and Mo-based BCC phase with increasing substitution of Mo for Cr. The phase composition eventually transforms into a single Mo-based BCC phase when the amount of the substitution surpasses a certain level. PCT tests reveal that the maximum hydrogen storage capacity increases with increasing Mo content. The hydrogenation-induced phase changes are also greatly influenced by the substitution of Mo for Cr. SEM tests of the hydrided alloys show that the increasing Mo content enhances hydrogenation-induced pulverization. Finally, hydrogenation-induced phase changes during the course of activation are also investigated.