V–W alloy membranes for hydrogen purification

• Published in: Journal of alloys and compounds 2011-09, Vol.509, p.S881-S884
• Main Authors: Yukawa, H., Nambu, T., Matsumoto, Y.
• Format: Article
• Language: English
• Subjects: Alloying effects; DBTC; Hydrogen embrittlement; Hydrogen permeability; Hydrogen permeable membrane; Hydrogen solubility; Hydrogen storage; Membranes; Permeability; Resistance to hydrogen embrittlement; Solubility; Temperature; V-based alloy; Vanadium base alloys
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2010.09.161

▶ V–5 mol%W alloy possesses excellent hydrogen permeability together with strong resistance to hydrogen embrittlement. ▶ V-W alloy exhibits better mechanical properties than Nb-W alloy in hydrogen atmosphere at high temperature. ▶ Ductile-to-Brittle Transition hydrogen Concentration (DBTC) for pure V is determined to be about H/M = 0.22. ▶ Vanadium is ductile even in hydrogen gas atmosphere when dissolved hydrogen concentration is less than DBTC. ▶ Alloying effects and temperature dependence on the hydrogen solubility of vanadium is clarified. The alloying effects of tungsten on the hydrogen solubility and the hydrogen permeability are investigated for V-based hydrogen permeable membranes. The hydrogen solubility is found to decrease by the addition of tungsten into vanadium or by increasing the temperature. It is shown that the ductile fracture occurs for V–5 mol%W alloy even in the hydrogen pressures of 0.3 MPa at 773 K. It is also found that the mechanical properties (i.e., strength and ductility) of V-based alloy are better than that of Nb-based alloy in hydrogen atmosphere at high temperature. It is demonstrated that the V–5 mol%W alloy possess excellent hydrogen permeability without showing any hydrogen embrittlement when used under appropriate permeation conditions, i.e., temperature and hydrogen pressures.