SPD Processed Alloys as Efficient Vacancy-Hydrogen Systems
Nanocrystallization is known to yield several improvements for the storage and uptake rate of hydrogen in solids. Usually this process is achieved by ball milling to produce a nanopowders. However, handling of these powders is risky and difficult, and there is also a high risk of introducing impurities into the storage material. In this situation materials processed by Severe Plastic Deformation (SPD) yield several advantages: (i) the materials are produced in bulk shape with 100% density; (ii) the introduction of impurities is minimized, (iii) in addition to additional grain boundaries, many dislocations and particularly vacancies are generated which may further improve the hydrogen storage capacity and kinetics.
Witold Lojkowski and John R. Blizzard
A. K. Wieczorek et al., "SPD Processed Alloys as Efficient Vacancy-Hydrogen Systems", Solid State Phenomena, Vol. 114, pp. 177-182, 2006