V-W alloy membranes for hydrogen purification

▶ 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.