Hydrogen sorption of Mg-based mixtures elaborated by reactive mechanical grinding
SONG, Myoung-Youp
Division of Advanced Materials Engineering, Research Center of Advanced Materials Development
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Division of Advanced Materials Engineering, Research Center of Advanced Materials Development
SONG, Myoung-Youp
Division of Advanced Materials Engineering, Research Center of Advanced Materials Development
< Réduire
Division of Advanced Materials Engineering, Research Center of Advanced Materials Development
Langue
en
Article de revue
Ce document a été publié dans
Journal of Alloys and Compounds. 2002, vol. 336, n° 1-2, p. 292-296
Elsevier
Résumé en anglais
The use of mechanical grinding (MG) under H2 of magnesium powder improves the hydrogen sorption properties. The hydrogenation of Mg starts in situ during the milling process that allows suppressing the activation procedure ...Lire la suite >
The use of mechanical grinding (MG) under H2 of magnesium powder improves the hydrogen sorption properties. The hydrogenation of Mg starts in situ during the milling process that allows suppressing the activation procedure generally requested for Mg. The effects of the addition of various elements or compounds have been studied. The hydriding is a two-step process: nucleation and diffusion. A direct relationship exists between the nucleation duration and the specific surface. A critical milling time exists below which the diffusion process is improved and above which no further improvement is observed (the maximum internal stress in the powder is also reached at this critical time). The diffusion is controlled by the number of crystallites per particle that can be reduced by increasing the milling time up to 10 h. The addition of Co (catalyst), YNi (hydrogen pump) or oxides (abrasive element and nucleation centre) leads to an improvement of the hydrogen sorption properties (but a strong dependence upon the milling time is reported). Finally, the sorption properties of our mixtures are comparable with thus reported for MgH2-metal mixtures.< Réduire
Mots clés en anglais
Hydrogen absorbing materials
Alloys
Mechanical alloying
Kinetics
Origine
Importé de halUnités de recherche