Materials Science Forum, Vol.510-511, 534-537, 2006
Hydrogen absorption kinetics of Ti-Nb-Cr alloys
The Ti-Cr systems are known to consist of BCC solid solution, C36, C14, C15 Laves phase at high temperature. Among others, BCC solid solution phase has been reported to have a high hydrogen storage capacity. However, activation, wide range of hysteresis at hydrogenation/dehydrogenation, and degradation of hydrogen capacity due to hydriding/dehydriding cycles have to be improved for its application. In this study, for improving such a problem, we added on Nb. To obtain a target materials, Ti-1Nb-lOCr, Ti-3Nb-10Cr and Ti-5Nb-10Cr specimens were prepared by planetary ball mill. The milling process was carried out under nitrogen atmosphere. Specimens synthesized were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermo gravimetric analysis/differential scanning calorimetry(TG/DSC). In order to examine hydrogen absorption kinetics, Sievert's type automatic pressure-composition-isotherm (PCI) was performed at 293, 323, 373 and 423K under 1, 5MPa hydrogen atmosphere.
Keywords:BCC solid solution;Ti-Nb-Cr systems;hydriding/dehydriding;planetary ball mill;pressure-composition;isotherm (PCI)