Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7719109 | International Journal of Hydrogen Energy | 2014 | 9 Pages |
Abstract
The hydrogen permeability of cast Nb30Ti35Ni35âxCox (x = 0â¦35) alloys is found to increase with the Co content, induced by the tailored microstructures containing high fractions of eutectic and less primary phase. Among the cast alloys, Nb30Ti35Co35 consisting entirely of eutectic exhibits the highest permeability, particularly 2.65 Ã 10â8 mol H2 mâ1 sâ1 Paâ0.5 at 673 K. This permeability is further increased to 3.58 Ã 10â8 mol H2 mâ1 sâ1 Paâ0.5 by aligning eutectic grains perpendicularly to the membrane surface using directional solidification. The high permeability is attributed to the high hydrogen solubility and diffusivity in alloys. Our work demonstrates that hydrogen permeable alloys containing high fractions of eutectic may exhibit high permeability by adequately optimizing morphology, volume fraction and alignment of the bcc-Nb phase in the eutectic as the pathways for hydrogen permeation.
Related Topics
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Authors
Xinzhong Li, Erhu Yan, Markus Rettenmayr, Dongmei Liu, Yanqing Su, Jingjie Guo,