Rare earth sintered magnet, method of manufacturing rare earth sintered magnet, rotor, and rotating machine
AssigneeMitsubishi Electric Corporation
InventorsAkito IWASAKI, Yoshikazu NAKANO, Yasutaka NAKAMURA, Yukina YOSHIOKA
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Abstract
A rare earth sintered magnet has a main phase and a grain boundary phase, the main phase has an R2Fe14B crystal structure, rare earth elements R include at least Nd and Sm, and the content of Sm is higher in the main phase than in the grain boundary phase. The rare earth elements R may include La. In this manner, the higher content of Sm in the main phase than in the grain boundary phase suppresses the heat generation of the rare earth sintered magnet due to eddy current loss.
Claims13
-9. (canceled)
A rare earth sintered magnet comprising a main phase and a grain boundary phase, wherein
- the main phase has an R2Fe14B crystal structure,
- rare earth elements R include at least Nd and Sm, and
- a content of the Sm is higher in the main phase than in the grain boundary phase.
A method of producing a rare earth sintered magnet comprising:
- a pulverization process of pulverizing an R—Fe—B system rare earth magnet alloy containing at least Nd and Sm as rare earth elements R;
- a molding process of molding a powder of the R—Fe—B system rare earth magnet alloy to produce a compact;
- a sintering process of sintering the compact between 600 deg C. and 1300 deg C, inclusive, to produce a sintered compact;
- and
- a cooling process of holding the sintered compact at a temperature between 227 deg C. and 427 deg C, inclusive, for 0.1 hours to 5 hours.
Dependencies are inferred from the claim text.