Alloying Effects on the Hydrogen Diffusivity during HydrogenPermeation through Nb-based Hydrogen Permeable Membranes

摘要

The hydrogen solubility and the hydrogen permeability have been measured for Nb-basedalloys in order to investigate the alloying effects on the hydrogen diffusivity during hydrogenpermeation. The hydrogen diffusion coefficient during hydrogen permeation is estimated from alinear relationship between the normalized hydrogen flux, J d, and the difference of hydrogenconcentration, ΔC, between the inlet and the outlet sides of the membrane. It is found that thehydrogen diffusion coefficient during the hydrogen permeation is increased by alloying ruthenium ortungsten into niobium. On the other hand, the activation energy for hydrogen diffusion in pureniobium under the practical permeation condition is much higher than the reported values measuredfor dilute hydrogen solid solutions. It is interesting that the activation energy for hydrogen diffusiondecreases by the addition of ruthenium or tungsten into niobium.