Surface characteristics of fluorinated hydriding alloys

To overcome the shortcomings of hydriding alloys such as poor initial activation characteristics, high sensitivity to impurities and pyrophoricity, a new surface treatment method has been developed by employing an F--containing aqueous solution. It has been successfully applied to AB, AB(2), A(2)B and AB(5) type alloys. Distinguished characteristics have been obtained by fluorinating alloy surfaces. In this work, the surface structures and compositions of the fluorinated AB, AB(2), A(2)B and AB(5) type alloys were determined by means of SEM, EPMA and XPS. The reactivity and stability of the fluorinated surface were examined after exposing fluorinated alloys to water and air for various periods, and after repeating hydriding/dehydriding (HID) cycles with pure and impure hydrogen containing CO. It is the main purpose of this paper to reveal the surface structures and compositions of the fluorinated fine powder alloys, and to reveal the relationship between fluorinated surface structures and improved reaction characteristics in both gas-solid and liquid-solid systems.