Method for manufacturing a rear earth magnet
2022-07-31
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Rare earth alloy powder having an oxygen content of 50 to 4000 wt. ppm and a nitrogen content of 150 to 1500 wt. ppm is compacted by dry pressing to produce a compact. The compact is impregnated with an oil agent and then sintered. The sintering process includes a first step of retaining the compact at a temperature of 700°C to less than 1000°C for a period of time of 10 to 420 minutes and a second step of permitting proceeding of sintering at a temperature of 1000°C to 1200°C. The average crystal grain size of the rare earth magnet after the sintering is controlled to be 3 µ m to 9 µ m.