Gas phase hydrogen permeation in palladium-25 % silver

A hydrogen permeation facility based on an ultra high vacuum system was assembled with the ultimate goal to investigate gas phase hydrogen permeation through various metal foils. The system was designed with a membrane holder that does not require welding or brazing of the membrane to the supporting flange.; Hydrogen permeation experiments were carried out on cold rolled Pd-25% Ag foils with a thickness of 127 mum at 350°C for various time intervals and a constant flow rate of hydrogen. The effect of hydrogen permeation on the microstructure of the membrane material was studied by X-ray diffraction.; The results have shown an unexpected through-thickness texture gradient in the as-received Pd alloy. With the exception of a minor stabilization effect for one specific texture component, gas phase hydrogen permeation for up to 48 hours at 350°C has no significant effect on the crystal orientation with respect to the membrane surface.