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 TiCrB_0.9-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 TiB_1.07CrB_1.93 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.