The Changes of the Hydrogenation Properties of Zr_0.9Ti_0.1Cr_0.7Fe_1.3 Alloy Upon the Pressure Induced Hydriding-Dehydriding Cycling

수소흡수-방출 사이클에 의한 Zr_0.9Ti_0.1Cr_0.7Fe_1.3 합금의 수소화 반응 특성의 변화

The effect of pressure cycling of $Zr_{0.9}Ti_{0.1}Cr_{0.7}Fe_{1.3}$ on the hydrogenation properties was investigated using the P-C-Isotherm curves and hydrogen absorption rate curves in the isotherm condition. The reversible hydrogen absorption capacity was decreased about 45 % after 3300 cycles. In the case of activated sample, the rate controlling steps of hydriding reaction changed from the surface reaction to the hydrogen diffusion process through hydride phase sequentially as reaction proceeded. After 3300 cycles, the sequential change of rate controlling step was same as activated one. However, the hydrogen absorption rate significantly decreased. It is suggested that the degradation of $Zr_{0.9}Ti_{0.1}Cr_{0.7}Fe_{1.3}$ can be interpreted with the formation of $ZrFe_3$ phase at the particle surface.