Reversible hydrogen absorption in a Ti-6Al-4V alloy produced by mechanical alloying

Hydrogen absorption in a Ti-6Al-4V alloy prepared by ball milling was investigated in view of the reversible storage of hydrogen in a solid state. The material characterization by X-ray and neutron diffractometry demonstrated the formation of a single ? phase whose unit cell expanded during the hydrogen absorption. The maximum storage capacity of this ? phase was 1.8 wt% H and no hydride formation was observed. The existence of such a particular supersaturated hexagonal phase was attributed to the strongly defective structure formed by the mechanical alloying process.