Crystallization kinetics and phase transition under high-pressure of amorphous Sm8Fe85Si2C5 alloy

Citation
Xy. Zhang et al., Crystallization kinetics and phase transition under high-pressure of amorphous Sm8Fe85Si2C5 alloy, ACT MATER, 49(19), 2001, pp. 3889-3897
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
ACTA MATERIALIA
ISSN journal
1359-6454 → ACNP
Volume
49
Issue
19
Year of publication
2001
Pages
3889 - 3897
Database
ISI
SICI code
1359-6454(20011114)49:19<3889:CKAPTU>2.0.ZU;2-R
Abstract
The crystallization kinetics and phase transition under high pressure of am orphous Sm8Fe85Si2C5 have been investigated. The activation energy of cryst allization of both alpha -Fe and Sm-2(Fe,Si)(17)C-x phases in the alloy is larger at the beginning of crystallization, and it undergoes little change in a larger range of crystallized fraction. This essentially results in the formation of an alpha -Fe/Sm-2(Fe,Si)(17)C-x composite microstructure with a relatively coarse grain size. High pressure has a large effect on the ph ase transition of the amorphous alloy as it is annealed at 923 K. By increa sing pressure from normal pressure to 6 GPa, the grain size of crystalline phases decreases from 30.6 to 6.4 nm for the alpha -Fe phase and from 28.7 to 5.8 nm for the Sm-2(Fe,Si)(17)C-x phase. A small grain size of less than 10 nm is required by theoretical models for enhancing magnetic properties of the composites. The volume fraction of Sm-2(Fe,Si)(17)C-x increases with pressure, As pressure increases to 6 GPa, a change in crystallization sequ ence between the alpha -Fe phase and the Sm-2(Fe,Si)(17)C-x phase is observ ed. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All ri ghts reserved.