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Long-term hydrogen storage in Mg and ZK60 after Severe Plastic Deformation.

Long-term hydrogen storage in Mg and ZK60 after Severe Plastic Deformation.

Authors :
Grill, Andreas
Horky, Jelena
Panigrahi, Ajit
Krexner, Gerhard
Zehetbauer, Michael
Source :
International Journal of Hydrogen Energy. Dec2015, Vol. 40 Issue 47, p17144-17152. 9p.
Publication Year :
2015

Abstract

This paper reports long-term hydrogen storage experiments on MgH 2 and on the Mg alloy ZK60 following prior Severe Plastic Deformation (SPD). Although SPD processing leads to significant enhancements of hydrogen absorption and desorption rates in both materials, these are not necessarily stable with respect to repeated loading/unloading cycles. Cold rolled (CR) MgH 2 shows a reduction of capacity by 30% after 100 cycles. In contrast, in ZK60 (Mg-5Zn-0.8Zr) processed by High Pressure Torsion (HPT), both kinetics and storage capacity are stable for at least 200 absorption/desorption cycles. Analysis by means of Johnson-Mehl-Avrami theory clearly suggests that in the case of CR MgH 2 nucleation is followed by growth of extended MgH 2 domains leading to a gradual deterioration of hydrogen diffusion and storage/release characteristics. In the case of HPT ZK60, however, no further growth occurs subsequent to nucleation thus allowing for permanently enhanced hydrogen diffusion and stable storage/release properties. These results can be understood in terms of the different density and stability of SPD-induced lattice defects acting as nucleation sites in both materials studied. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
03603199
Volume :
40
Issue :
47
Database :
Academic Search Index
Journal :
International Journal of Hydrogen Energy
Publication Type :
Academic Journal
Accession number :
111296418
Full Text :
https://doi.org/10.1016/j.ijhydene.2015.05.145