METHOD OF MANUFACTURING DUST COMPACT FOR MAGNET, DUST COMPACT FOR MAGNET, AND BAKED BODY

摘要

PROBLEM TO BE SOLVED: To provide a method of manufacturing a dust compact for a magnet capable of manufacturing, at high productivity, a dust compact for providing a rare earth baked magnet excellent in magnet property, and to provide a dust compact for a magnet, along with a baked body, which is excellent in directivity and suitable for a material of the rare earth baked magnet.

SOLUTION: Material powder P formed of rare earth alloy, containing fine particles, whose particle size is 2 μm or less, by 15 mass % or more, is packed in a molding die 50, and pressurized/compressed, and a magnetic field is applied to form a dust compact. A weak magnetic field of 1T-2T is applied to a powder compact whose packing density is 1.05-1.2 in bulk density to provide a compact 10. The compact 10 is excited at 3T or higher at excitation speed of 0.01 T/sec or more to 0.15 T/sec or less, so that a strong magnetic field of 3T or higher is applied by a high temperature superconducting coil 60. A magnetic field is applied by the high temperature superconducting coil 60 in the direction opposite to the application direction of magnetic field by a normal conducting coil 70 while a high speed excitation is performed, so that fine particles are rotated together with coarse particles, for improved directivity.

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