Crystallisation and phase decomposition processes in Pr4.5Fe77B18.5 amorphous ribbon

Citation
Yc. Jung et al., Crystallisation and phase decomposition processes in Pr4.5Fe77B18.5 amorphous ribbon, MATER TRANS, 42(10), 2001, pp. 2102-2111
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Material Science & Engineering
Journal title
MATERIALS TRANSACTIONS
ISSN journal
1345-9678 → ACNP
Volume
42
Issue
10
Year of publication
2001
Pages
2102 - 2111
Database
ISI
SICI code
1345-9678(200110)42:10<2102:CAPDPI>2.0.ZU;2-G
Abstract
The isothermal crystallisation processes and the decomposition behaviours o f the crystallised phases in Pr4.5Fe77B18.5 amorphous ribbons prepared by a melt quench technique have been investigated by means of differential ther mal analysis, X-ray diffraction, and high resolution transmission electron microscopy, and the following results were obtained. The phase initially cr ystallised is Fe3B and the crystallisation of Pr2Fe23B3 particles occurs im mediately after the Fe3B formation. This is probably due to the fact that F e3B/amorphous interphase boundaries provide potent nucleation sites for Pr2 Fe23B3 particles in view of chemistry in the vicinity of Fe3B particles and the structure of the interfaces. Then, fine hard magnetic Pr2Fe14B particl es nucleate at Fe3B interfaces directly. In the following processes, Pr2Fe1 4B and Pr2Fe23B3 particles grow by the coalescence of fine particles. In th e later annealing stages, Pr2Fe23B3 particles decompose into Pr2Fe14B netwo rks involving spherical alpha -Fe particles in a eutectoid-like mode. At th e final stage of annealing these Pr2Fe14B networks transform in-situ into t hose of Pr2Fe14B.