Influences of Partial Substitution of VFe Alloys for Cr on Structure and Hydrogen Storage Performances of TiCr1.8 Alloy

Influences of partial substitution of VFe alloys for Cr on structure and hydrogen storage performances of TiCr1.8 alloy were studied by XRD, PCT and TG-DSC methods. Results show that phase composition gradually changes from single Laves phase to BCC phase. Crystal cell parameters are enlarged by increasing of VFe content in alloys. The maximum hydrogen capacity increases also with the increase of VFe content in alloys. It is up to 5.2/a. f. u. (the unit of a.f.u. means the ratio of the number of absorbed hydrogen atoms to alloys formula unit) corresponding to 3.4% in mass. The reversible hydrogen storage capacity increases first, but then decreases with the increase of VFe content in alloys. There are two kinds of positions with different combining energy for hydrogen storage in TiCr1.2(VFe)0.6 alloy with BCC phase.