Long term hydrogen storage properties of ZK60 Mg-alloy as processed by different methods of SPD

Author(s)
P. Cengeri, Y. Kimoto, M. Janoska, Z. Abbasi, Y. Morisada, H. Fujii, N. Enzinger, Ch Sommitsch, G. Boczkal, G. Krexner, M. J. Zehetbauer, E. Schafler
Abstract

Hydrogen storage characteristics is studied in the Mg-alloy ZK60 after processing by different SPD (Severe Plastic Deformation) methods such as High Pressure Torsion (HPT) and Friction Stir Processing (FSP), applying various deformation extents and rates. The capacity and kinetics of hydrogen storage was investigated and analysed, up to 100 storage cycles. While the degree of SPD deformation is less important for the storage capacity, the SPD processing method itself matters, yielding about ~ 30% more capacity in FSP than in HPT. As shown by DSC and XRD analyses, it is the density of SPD-induced vacancy agglomerates which is significantly higher in FSP than in HPT (~ 10–3 instead of ~ 10–4) because of the enhanced dislocation slip activity. Thanks to their stabilization through Mg(Zn,Zr) precipitates, the vacancy agglomerates survive numerous cycles of hydrogen storage in spite of the high storage temperature of 350 °C, and can act as thermally stable heterogeneous nuclei for the hydrogenation. This latter mechanism was found in all SPD methods applied irrespective of the deformation extent, on the basis of Johnson–Mehl–Avrami-Kolmogorov analysis providing the Avrami exponent n = 1, already from the second up to the highest hydrogen storage cycles.

Organisation(s)
Dynamics of Condensed Systems, Physics of Functional Materials
External organisation(s)
Osaka University, AGH University of Science and Technology, Universität Wien, Karlsruher Institut für Technologie, Osaka Research Institute of Industrial Science and Technology, Technische Universität Graz
Journal
Journal of Materials Science
Volume
59
Pages
5906-5922
No. of pages
17
ISSN
0022-2461
DOI
https://doi.org/10.1007/s10853-024-09529-0
Publication date
04-2024
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics
ASJC Scopus subject areas
Ceramics and Composites, Materials Science (miscellaneous), Materials Science(all), Mechanics of Materials, Mechanical Engineering, Polymers and Plastics
Portal url
https://ucris.univie.ac.at/portal/en/publications/long-term-hydrogen-storage-properties-of-zk60-mgalloy-as-processed-by-different-methods-of-spd(40577bff-efd7-4f59-be5d-f2ec1815cbc4).html