Alloying effects on the stability of vanadium hydrides

The alloying effects on the stability of the γ phase (VH2) and the β phase (VH or V2H) was investigated experimentally in binary V-1mol%M and V-3mol%M alloys, where M represents various alloying elements. It was found that the stability of the γ phase is dependent largely on the alloying elements, and changes systematically following the order of elements in the periodic table. On the other hand, two endothermic peaks are observed in the course of hydrogen desorption from the β phase in the DSC experiments. They are attributable to the onset of the successive transformations of the β phase to the bcc(α) phase containing hydrogen and then of this bcc(α) phase to the hydrogen-free bcc vanadium. Both the peak profile and the peak temperature vary significantly with alloying elements, M, indicating that the hydrogen desorption from the β phase is strongly modified by alloying.