High-pressure hydrogenation properties of Ti-V-Mn alloy for hybrid hydrogen storage vessel

Ti-V-Mn alloys, which are one of the suitable materials for a high-pressure hybrid hydrogen storage vessel of 35 MPa, have been evaluated the hydrogenation properties and the microstructures. Among the Ti-V-Mn alloys produced by as-cast arc melting and annealing treatment at 1223 K, a Ti0.5V0.5Mn alloy particularly absorbed hydrogen up to 2.1 wt% at 260 K under 35 MPa H2. The hydrogen desorption pressure isotherm showed sloping plateau in the range of 0.3-0.6 MPa at 260 K. This effective hydrogen capacity under H2 pressure from 35 to 0.1 MPa was 1.9 wt%. The alloy mainly consisted of the hexagonal C14 Laves and BCC phases. The microstructure of the several phases in the alloy was revealed by transition electron microscopy (TEM).