Microstructure of Cold Rolled Magnesium and Magnesium Hydrides for Hydrogen Storage Applications
J. LANG1, N. SKRYABINA2, D. FRUCHART3, M. DANAIE4 and J. HUOT1
1Chemistry and Physics Department, Universitй du Quйbec а Trois-Riviиres, 3351 des Forges, Trois-Riviиres, Quйbec, G9A 5H7 (Canada)
2Department of Physics, Perm State University, Ul. Bukireva 15, Perm 614990 (Russia)
3Institut Nйel BP 166, 38042 Grenoble Cedex 9 (France)
4Department of Materials
Science and Engineering, McMaster University, Hamilton, Ontario (Canada)В
Keywords: hydrogen absorbing materials, magnesium alloys, cold rolling, gas-solid reactions
Pages: 545–552
Abstract
It has recently been shown that Severe Plastic Deformation (SPD), and particularly cold rolling, techniques could be used to obtain nanostructured metal hydrides with enhanced hydrogen sorption properties. Cold rolling is a particularly interesting technique because it is easily scalable to industrial level. We present here the effect of cold rolling on hydrogen storage properties of magnesium and magnesium hydride (MgH2). Commercial magnesium and magnesium hydride were processed in a vertical cold rolling apparatus. For pure magnesium, a highly textured material was obtained after only one roll and first hydrogenation was faster than unprocessed magnesium. In the case of magnesium hydride, after only five rolling passes hydrogen sorption kinetics at 623 K were greatly enhanced without noticeable loss of capacity. The improvement in sorption kinetics is attributed due to the nanocrystalline structure and number of created defects. Investigation of the powder morphology and crystal structure indicates that cold rolling is equivalent to ball milling.
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