Oxidation kinetics of Nd-Fe-B permanent magnets with modified microstructure
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Beijing University of Technology, Beijing 100022 (China)
Oxidation kinetics of Nd-Fe-B permanent magnets prepared by both spark plasma sintering (SPS) and conventional sintering techniques has been studied at elevated temperature in dry air environment. Compared with the conventional sintered magnet, the SPS magnet possesses much lower oxidation rate, which leads to less reduction of magnetic properties of the SPS magnet than that of the conventional sintered magnet. Microstructure observation shows that the SPS magnet possesses unique microstructure due to the special sintering mechanism of SPS technique. In detail, the grain size of the Nd{sub 2}Fe{sub 14}B main phase is fine and uniform, only a few Nd-rich phases form along the grain boundaries of Nd{sub 2}Fe{sub 14}B phase, while most of them agglomerate into triple junctions as small particles. Such microstructure modification restrains effectively the intergranular corrosion along Nd-rich phase in the SPS magnet. As a result, the SPS magnet possesses excellent corrosion resistance at elevated temperature.
- OSTI ID:
- 21137317
- Journal Information:
- Journal of Applied Physics, Vol. 103, Issue 7; Conference: 52. annual conference on magnetism and magnetic materials, Tampa, FL (United States), 5-9 Nov 2007; Other Information: DOI: 10.1063/1.2830529; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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