DocumentCode :
1153694
Title :
Homogenisation behaviour of Nd2(Fe0.98Nb0.02)14B alloy
Author :
Ahmed, Fathalla M. ; Edgley, Donald S. ; Gutfleisch, Oliver ; Harris, Ivor R.
Author_Institution :
Sch. of Metall. & Mater., Birmingham Univ., UK
Volume :
30
Issue :
2
fYear :
1994
fDate :
3/1/1994 12:00:00 AM
Firstpage :
616
Lastpage :
618
Abstract :
The effects of the homogenisation conditions on the microstructure of a Nd2(Fe0.98Nb0.02)14B alloy have been investigated. In the as cast condition the microstructure of the alloy contains four phases, the Nd2Fe 14B matrix phase, a Nb-containing ternary phase (Nb26 Fe32B42), Nd-rich regions and free iron. In contrast, the homogenised alloy contains only the first two phases and very small amounts of the Nd-rich phase. The Nb26Fe32 B42 ternary phase was found to originate (nucleate) in the heart of the free iron phase which provides strong evidence for the role of Nb in the removal of free iron from the microstructure. The electrical resistivity of the alloy was measured at regular intervals during the homogenisation process at 1000°C and these studies revealed that, after 40 hours, the alloy was completely homogenised and this was in a good agreement with the microstructural studies. The resistance measurements also indicated a degree of anisotropy in the as-cast material and there was a maximum in resistance at an intermediate stage which could indicate an age hardening process. The resistance was found to correspond to a microhardness value
Keywords :
boron alloys; crystal microstructure; electrical conductivity of crystalline metals and alloys; ferromagnetic properties of substances; hardness; heat treatment; iron alloys; magnetic anisotropy; neodymium alloys; niobium alloys; 1000 C; Nb26Fe32B42 ternary phase; Nd-rich phase; Nd2(Fe0.98Nb0.02)14B; Nd2(Fe0.98Nb0.02)14B alloy; Nd2Fe14B matrix phase; age hardening; anisotropy; as-cast material; electrical resistivity; free iron phase; homogenisation; microhardness; microstructure; nucleation; Cooling; Electric resistance; Electrons; Iron alloys; Magnetic properties; Microstructure; Neodymium; Niobium alloys; Scattering; Temperature;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/20.312353
Filename :
312353
Link To Document :
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