Hydrogen storage alloys are suitable materials to absorb hydrogen as a type of hydrogen compounds and can easily absorb or release hydrogen by controlling the temperature and pressure. Therefore, they can be promising materials for hydrogen storage system. However, BCC type alloy based on Ti-V has a slow reaction rate and it is difficult to activation for storing hydrogen. In this study, the third and forth elements were added in order to improve hydrogen storage properties in BCC type alloy. Ti-V-Cr based alloys were prepared by arc-melting and then they were ball milled for 4 hours.
Alloys with the Ti/Cr ratio of about 0.84 showed a good hydrogen storage capacity. The maximum hydrogen content and the effective hydrogen capacity were 3.13 wt.% and 2.15 wt.%, respectively. The effect of vanadium content on the Ti-V-Cr based alloys, no significant increase of hydrogen storage capacity was observed. The effect of partial substitution of manganese for vanadium in the Ti_0.34V_0.26Cr_0.38 alloy on the properties was investigated, as generally addition of Mn is considered to expand the plateau range. The partial substitution of Mn in the ternary alloy expanded the plateau range and lowered the plateau pressure. At the same time, the maximum storage capacity was increased. The small amount of Mn addition was increased hydrogen storage capacity. The Ti_0.34V_0.26Cr_0.38Mn_0.02 alloy exhibited 3.4 wt.% hydrogen storage capacity and 0.2 wt.% higher than that of the ternary alloy without Mn element.