LAUSR

The defect structure of annealed cast, electron beam melted and ultrafine-grained titanium Ti–6Al–4V alloys before and after hydrogenation was studied. It has been established that before hydrogenation the predominant types of defects in electron beam melted and ultrafine-grained titanium alloy are dislocations and low-angle boundaries, respectively. The cast alloy after annealing is defect-free material. Hydrogenation from the gas phase to 1.00 ± 0.15 wt% leads to an increase of the concentration of the predominant type of defects. Moreover, vacancy complexes also presented in electron beam melted and ultrafine-grained Ti–6Al–4V alloys interact with hydrogen and form hydrogen–vacancy complexes.