Title :
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
fDate :
9/1/1990 12:00:00 AM
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 Nd14.5Fe63Co16Ga1B5.5 were obtained: (BH)max=114 kJ/m3, Br=0.89 T, and iHc=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; Nd14.5Fe63Co16Ga1B 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;
Journal_Title :
Magnetics, IEEE Transactions on
