Sorry, you need to enable JavaScript to visit this website.

Hydrogenation-induced microstructure evolution in as cast and severely deformed Mg-10 wt.% Ni alloy

TitleHydrogenation-induced microstructure evolution in as cast and severely deformed Mg-10 wt.% Ni alloy
Publication TypeArticolo su Rivista peer-reviewed
Year of Publication2013
AuthorsPopilevsky, L., Skripnyuk V.M., Estrin Y., Dahle A., Mirabile Gattia Daniele, Montone Amelia, and Rabkin E.
JournalInternational Journal of Hydrogen Energy
Volume38
Pagination12103-12114
ISSN03603199
KeywordsAlloys, Cerium alloys, Equal channel angular pressing, Eutectic alloys, Hydrogen, Hydrogen absorption, Hydrogen storage, Hydrogen storage properties, Hydrogen-absorption kinetics, Hydrogenation, Hydrogenation cycle, Magnesium alloys, Micro-structure evolutions, Microstructural changes, Microstructure, Nickel, Transformation stress
Abstract

We determined the kinetics of hydrogen absorption of the hypoeutectic Mg-10 wt.% Ni alloy in the as-cast state and after processing by four passes of equal channel angular pressing (ECAP). While during the first hydrogenation cycle the ECAP-modified alloy exhibited faster absorption than its as-cast counterpart, this advantage was lost after the second hydrogenation cycle; parity was regained after six cycles. We attributed these differences in the hydrogen absorption kinetics to the formation of large (tens of micrometers) faceted Mg crystals observed during the first hydrogenation cycle. These crystals were significantly larger in the ECAP-modified alloy than in its as-cast counterpart. We discussed the growth of large Mg crystals during hydrogenation in terms of self-diffusion of Mg atoms driven by the metal-hydride transformation stress. The larger size of these crystals in the ECAP-processed alloy was attributed to the acceleration of diffusion by ECAP. Our metallographic studies revealed a number of microstructural changes in the alloys upon hydrogenation, such as cracking, accumulation of plastic strain in large Mg crystals, and re-distribution of the dispersed particles of Mg2Ni phase in the partly hydrogenated alloys. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights.

Notes

cited By 2

URLhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-84882595549&doi=10.1016%2fj.ijhydene.2013.03.034&partnerID=40&md5=442b669d43c6244015701ee0687fed5e
DOI10.1016/j.ijhydene.2013.03.034
Citation KeyPopilevsky201312103