International Journal of Hydrogen Energy, Vol.41, No.4, 2781-2787, 2016
Influence of Fe on hydrogen storage properties of V-rich ternary alloys
To investigate the influence of Fe on Ti-V-Cr hydrogen storage alloy, Ti35-0.5xV40Cr25-0.5xFex (x = 0, 2, 5, 6 at.%) alloys were prepared by arc melting under argon in open hearth crucible furnace. The microstructures were examined by scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDX), and the phases were identified by X-ray diffraction (XRD) using Cu-Ka radiation. Hydrogen storage characteristics were systematically investigated by pressure-composition-temperature PCT measurement at 303, 333 and 363 K. XRD result showed that the alloys contained primary BCC (V) and secondary alpha Ti and Laves phases. Fe reduced the cell volume and proportion of BCC phase. The proportion of BCC phase ranges from 67 to 90 area%, while secondary phase proportion was found to be 10 to 33 area%. Iron reduced the absorption/desorption capacity, increased the plateau pressure and promotes formation of alpha-phase hydride. The best hydrogen storage properties were obtained in Fe-free sample. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Ti-V based alloys;Microstructure;Laves phase;Phase analysis;Hydrogen storage characteristics