The ultimate rolling reduction rate of as-cast Nb–TiNi alloys was evaluated by measuring the thickness changes in cold-rolled samples. Furthermore, the effects of cold rolling and subsequent annealing upon hardness, microstructure, hydrogen permeability and hydrogen flux of as-cast Nb40Ti30Ni30 alloy (mol%) were examined by using a Vickers hardness tester, a scanning electron microscope, and a mass flow meter, respectively. The value of H permeability for the Nb40Ti30Ni30 alloy was reduced with increasing rolling reduction rate and attained to one third of the original one by 50% rolling reduction, but recovered to the original one by annealing at 1373K for 605ks. The H flux was inversely proportional to the membrane thickness at 673K. A flux of 12ccH2/cm2/min was attained for the sample with the thickness of 120μm. The present work demonstrated that rolling and subsequent annealing were effective and useful for the preparation of the hydrogen permeation Nb–TiNi alloy membrane.

Microstructure and Hydrogen Permeation of Cold Rolled and Annealed Nb40Ti30Ni30 Alloy. K.Ishikawa, S.Tokui, K.Aoki: Intermetallics, 2009, 17[3], 109-14