Effect of microstructure on hydrogenation of Zr_0.7Ti_0.3V₂ alloy

The microstructure and phase composition of Zr_0.7Ti_0.3V₂ alloy were investigated by SEM, EDS and XRD, respectively. Hydrogen absorption pressure-composition-temperature (PCT) property of the alloy was investigated by pressure reduction method at temperature ranging from 673 K to 823 K. The results indicate the dominant phases of the annealed alloy can be ascribed to ZrV₂ (C15 type), α-Zr and abundant V solid solution phases. After hydrogenation, the dominant phases can be ascribed to V₁₆Zr₈H_36.29, ZrH_1.801, and VH_2.01 phases. The wider and flatter plateau region can be found in the hydrogen absorption PCT curves. The BCC phase is beneficial to the hydrogen absorption kinetics and the HCP phase can improve the hydrogenation PCT characteristic. The multiphase structures make the Zr_0.7Ti_0.3V₂ alloy preserve excellent hydrogen absorption properties.