Abstract
Changes in magnetic properties after applying grain boundary diffusion process to Nd-Fe-B sintered magnets with a thickness of several millimeters were investigated, and their microstructures were also observed. Coercivities of the magnets coated with heavy rare earths (HRE=Dy and Tb) oxide or fluoride powder and then heat-treated, were enhanced significantly without a considerable reduction in a remanence. During the heat treatment, HRE element diffused into the magnet through the grain boundary, and formed HRE-rich shells around the grain boundary of the Nd2Fe14B phase by substituting Nd. The coercivity increased by more than 400 kA/m with a thickness of up to 3 mm for the magnet processed with TbF3.
Original language | English |
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Pages (from-to) | 2909-2911 |
Number of pages | 3 |
Journal | IEEE Transactions on Magnetics |
Volume | 42 |
Issue number | 10 |
DOIs | |
Publication status | Published - 2006 Oct |
Externally published | Yes |
Keywords
- Coercive force
- Dy2O3
- DyF3
- TbF3
- diffusion
- grain boundary
- powder
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering