Coercive force of Co added Nd-Fe-B based powders prepared by crushing sintered magnets

Author

Sakai, I. ; Tsutai, A. ; Sahashi, M. ; Inomata, K.

Author_Institution

Toshiba Corp., Kawasaki, Japan

Volume

26

Issue

5

fYear

1990

fDate

9/1/1990 12:00:00 AM

Firstpage

2616

Lastpage

2618

Abstract

An anisotropic resin-bonded magnet was prepared by crushing sintered Nd-Fe-B magnets with Co-Al or Co-Ga. The following magnetic properties for the composition of Nd_14.5Fe₆₃Co₁₆Ga₁B_5.5 were obtained: (BH)_max=114 kJ/m³, B_r=0.89 T, and iH_c=810 kA/m. Co addition is shown to play a significant role in improving the magnetic properties of the crushed powder. The surface layer damaged by crushing becomes thinner in the powder containing Co. In the Co-added sintered magnets, the main crack brought about by Vickers indentation is comparatively easy to propagate through the grain boundaries, and microcrack branchings are rarely observed. These mechanical properties are closely related to the thickness of the damaged surface layer. Al or Ga addition to the Nd-Fe-Co-B system is very effective for obtaining a high coercive force of the powder

Keywords

boron alloys; cobalt alloys; coercive force; cracks; ferromagnetic properties of substances; iron alloys; neodymium alloys; permanent magnets; Co addition; Nd_14.5Fe₆₃Co₁₆Ga₁B _5.5; Vickers indentation; anisotropic resin-bonded magnet; coercive force; crushing sintered magnets; grain boundaries; high coercive force; magnetic properties; mechanical properties; microcrack branchings; powders; surface layer; Anisotropic magnetoresistance; Coercive force; Grain boundaries; Iron; Magnetic anisotropy; Magnetic properties; Neodymium; Perpendicular magnetic anisotropy; Powders; Surface cracks;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.104816

Filename

104816