The diffusion of hydrogen in the tetrahedral interstitials of bulk spherical Laves phase ZrMn0.85Cr0.1V0.05Fe0.5Ni0.5 and ZrMn0.85Cr0.1V0.05Fe0.5Ni0.5-1wt%B alloys was studied in the α-phase (solid-solution) region at 450 to 650C, for hydrogen pressures up to 100mbar using Sieverts-type apparatus. The diffusion constants were determined from the gas–solid reaction, where the gas pressure dependence upon time was measured at a fixed temperature (table 6). The results were analysed in terms of Fick's diffusion law. The dependence of the diffusion constant upon alloy composition and initial pressure was evaluated. The activation energy was obtained from the temperature dependence of diffusion, using the Arrhenius relationship (table 7).

Hydrogen Diffusion Studies in Zr-Based Laves Phase AB2 Alloys. A.L.M.Reddy, S.Ramaprabhu: Journal of Alloys and Compounds, 2008, 460[1-2], 268-71

Table 6

Diffusivity of H in Zr-Mn-Fe-Ni-Cr-V Alloys at 650C