Toyota Jidosha Kabushiki Kaisha

Nichia Corporation

Reimi Tabuchi

Motoki Hiraoka

Masaaki Ito

Hisashi Maehara

Michiya Kume

Masanori Okanan

A Sm—Fe—N-based rare earth magnet more resistant to demagnetization than ever before, particularly at high temperatures, and a production method thereof are provided. The present disclosure presents a production method of a rare earth magnet, including mixing a SmFeN magnetic powder and a modifier powder to obtain a mixed powder, compression-molding the mixed powder in a magnetic field to obtain a magnetic-field molded body, pressure-sintering the magnetic-field molded body to obtain a sintered body, and heat-treating the sintered body, and a rare earth magnet obtained by the method. Dof the magnetic powder is 1.50 μm or more and 3.00 μm or less, the content ratio of the zinc component in the modifier powder is 6 mass % or more and 30 mass % or less, and the heat treatment temperature is 350° C. or more and 410° C. or less.

Rare earth magnet and production method thereof

A Sm—Fe—N-based rare earth magnet more resistant to demagnetization than ever before in an environment where an external magnetic field is applied, particularly at high temperatures, and a production method thereof are provided. The present disclosure presents a production method of a rare earth magnet, including preparing a coated magnetic powder, compression-molding the coated magnetic powder in a magnetic field to obtain a magnetic-field molded body, pressure-sintering the magnetic-field molded body to obtain a sintered body, and heat-treating the sintered body, and a rare earth magnet obtained by the method. Dof the magnetic powder in the coated magnetic powder is 1.50 μm or more and 3.00 μm or less, the content ratio of the zinc component in the coated magnetic powder is 3 mass % or more and 15 mass % or less, and the heat treatment temperature is 350° C. or more and 410° C. or less.

The present invention is a method for producing a rare earth magnet, including preparing a magnetic powder and a modifier powder, mixing them to obtain a mixed powder, compression-molding the mixed powder in a magnetic field to obtain a magnetic-field molded body, and pressure-sintering the magnetic-field molded body to obtain a sintered body, wherein the magnetic powder includes a first particle group and a second particle group, the Dvalues of the first particle group and the second particle group are denoted by dμm and dμm, respectively, dand dsatisfy the relationship of 0.350≤d/d≤0.500, and the ratio between the total volume of the first particle group and the total volume of the second particle group is from 9:1 to 4:1; and a rare earth magnet obtained by the production method.

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Nisshin, Japan

Reimi Tabuchi