METHOD FOR PRODUCING SINTERED BODY THAT FORMS RARE-EARTH PERMANENT MAGNET AND HAS NON-PARALLEL EASY MAGNETIZATION AXIS ORIENTATION

摘要

Provided is a method for producing a sintered body that forms a rare-earth permanent magnet, has a single sintered structure and an arbitrary shape, and has easy magnetization axis orientations of different directions applied to the magnet material particles in a plurality of arbitrary regions. This method forms a three-dimensional first molded article from a composite material formed by mixing a resin material and magnet material particles containing a rare-earth substance. While keeping the first molded article at a temperature higher than the softening temperature of the resin, a parallel external magnetic field having parallel magnetic flux is imparted to the first molded article, and as a result, the axis of easy magnetization of the magnet material particles is oriented in parallel to the direction of the external magnetic field. Then, by subjecting the first molded article to a deforming force such as one that changes the horizontal cross-sectional shape of at least one section of a horizontal cross-section of the first molded article, a second molded article is formed in which the orientation direction of the easy magnetization axis of the magnet material particles in at least the one section of the horizontal cross-section is changed to a direction which differs from the orientation direction of the first molded article. The second molded article is heated to a sintering temperature and kept at the sintering temperature for a prescribed period of time. The resin inside the second molded article is vaporized, which forms a sintered body in which the magnet material particles are sintered to one another.