2019-Sustainable Industrial Processing Summit
SIPS2019 Volume 3: Kobe Intl. Symp. / Science of Innovative and Sustainable Alloys and Magnets (SISAM)
| Editors: | F. Kongoli, M. Calin, J.M. Dubois, K. Zuzek-Rozman |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2019 |
| Pages: | 156 pages |
| ISBN: | 978-1-989820-02-5 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Between metastability and equilibrium in Fe-Ga functional alloys
Igor S. Golovin1; Valeria V. Palacheva1; AbdelKariem Mohamed1; Anatoly M. Balagurov2; Ivan A. Bobrikov2;1NATIONAL UNIVERSITY OF SCIENCE AND TECHNOLOGY 'MISIS', Moscow, Russian Federation; 2JOINT INSTITUTE OF NUCLEAR RESEARCH, Dubna, Russian Federation;
Type of Paper: Invited
Id Paper: 150
Topic: 42
Abstract:
The equilibrium phase diagram does not reflect the real structure of Fe-Ga alloys neither in the as cast state nor after annealing followed by air-cooling or furnace-cooling. Functional properties of the Fe-Ga alloys are extremely sensitive to particular details of the phase transition from the metastable (as-cast, as-quenched) state with A2 or D03 structures with positive magnetostriction to the equilibrium state with L12 structure and negative magnetostriction. They are also sensitive to short range ordering of the A2 metastable phase including the formation of local martensite-like structures.
In the present study, we have investigated the time-dependence and temperature-dependence of the transition of as-cast metastable Fe-(9-33at.%)Ga ‘Galfenol’ alloys to the equilibrium state along with corresponding changes in their functional properties and anelastic effects that accompany these transitions. To characterize such a time-temperature-transition diagram we used both long-time isochronal annealing (up to 300 hrs) and instant heating treatments with different temperature protocols. In-situ neutron diffraction at instant heating-cooling and isochronal annealing, XRD, DSC, VSM, SEM-EBSD, Mössbauer and mechanical spectroscopy techniques were used to study first and second order phase transitions, structure, and functional properties of Galfenols.
Keywords:
Advanced materials; Alloys; Magnetic Materials;References:
[1] I.S. Golovin, А.M. Balagurov, V.V. Palacheva, I.A. Bobrikov, V.B Zlokazov.Materials and Design, 98 (2016) 113-119
[2] V.V. Palacheva, A. Emdadi, F. Emeis, I.A. Bobrikov, A.M. Balagurov, S.V. Divinski, G. Wilde, I.S. Golovin. Acta Materialia 130 (2017) 229-239
[3] M.V. Matyunina, M.A. Zagrebin, V.V. Sokolovskiy, O.O. Pavlukhina, V.D. Buchelnikov, A.M. Balagurov, I.S. Golovin. Phase Transitions. 92 (2019) n.2, 101-116