Hydrogen-induced changes in the properties of Zr-based AB<inf>2</inf> alloy studied by x-ray, electrical resistivity and differential scanning calorimetry

Powder x-ray diffraction and the electrical resistivity of (Ti 0.1Zr0.9)1.1Mn0.9V 0.1Fe0.5Ni0.5-Hx with different hydrogen concentrations have been investigated and the results have been discussed. An experimental facility has been developed to measure the in situ electrical resistivity of alloys during the hydrogen absorption process. Variation in in situ electrical resistivity with hydrogen concentration in (Ti0.1Zr0.9)1.1Mn0.9V 0.1Fe0.5Ni0.5 has been explained using the phase transformation during hydrogen absorption. Differential scanning calorimetry (DSC) studies have been performed in (Ti0.1Zr 0.9)1.1Mn0.9V0.1Fe 0.5Ni0.5-Hx with different hydrogen concentrations in the temperature range 50-250 °C under argon atmosphere. The DSC studies show that the desorption of hydrogen is from the 24l (A 2B2) tetrahedral sites. The activation energies and diffusion coefficients of hydrogen in (Ti0.1Zr0.9) 1.1Mn0.9V0.1Fe0.5Ni0.5 have been determined in the range 30-100 °C from the hydrogen absorption kinetics measurements. The diffusion coefficient of hydrogen in (Ti 0.1Zr0.9)1.1Mn0.9V 0.1Fe0.5Ni0.5-Hx at 30 °C is 1.1 × 10-10 cm2 s-1. © 2006 IOP Publishing Ltd.