Microstructural study of as-cast Nd-Fe-B alloys

Author

Lemarchand, Dany ; Vial, F. ; Hauet, A. ; Labulle, Bernard ; Vigier, Pierre

Author_Institution

Fac. des Sci. de Rouen, Mont-Saint-Aignan, France

Volume

26

Issue

1

fYear

1990

fDate

1/1/1990 12:00:00 AM

Firstpage

253

Lastpage

256

Abstract

The primary solidification or iron in Nd-Fe-B alloys is detrimental to the magnetic properties of sintered magnets; around the compositions of the ferromagnetic φ phase (Nd₂Fe₁₄B) some fluctuations of the compositions and/or production processes control this solidification. A microstructural study of as-cast alloys by means of metallography, electron probe, and Mossbauer spectroscopy showed, besides the main φ phase, some amounts of α-Fe dendrites and intergranular precipitates of Nd_1.1Fe₄B₄ and of an Nd-rich phase. Following the observations, the boundary separating the primary crystallization field of Fe and φ can be more precisely defined. The optimal composition avoiding iron precipitation can be found

Keywords

Mossbauer effect; boron alloys; dendrites; electron probe analysis; ferromagnetic properties of substances; iron alloys; metallography; neodymium alloys; precipitation; solidification; Mossbauer spectroscopy; Nd-Fe-B; dendrites; electron probe; intergranular precipitates; magnetic properties; metallography; microstructural study; optimal composition; primary crystallization field; primary solidification; production processes; sintered magnets; Electrons; Fluctuations; Iron alloys; Magnetic properties; Magnets; Neodymium; Probes; Process control; Production; Spectroscopy;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.50549

Filename

50549