An anisotropic resin-bonded magnet was preparea by crushing sintered Nd-Fe-B magnets with Co-AI or Co-Ga. The authors have obtained the following excellent magnetic properties for the composition of Nd14. 5Fe63CO16Ga1B5.5: (BH) max=114 kJ/m3, Br=0.89 T and iHc=810 kA/m. Especially, Co addition plays a significant role in improving the magnetic properties of the crushed powder. The surface layer damaged by crushing becomes thinner in the Co containing powder. 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 is scarcely 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.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering