| 摘要 |
PURPOSE:To obtain a polymer composite type rare earth magnet which has extremely excellent magnetic characteristics by grinding sintered alloy powder to an appropriate grain size and by aging treatment at the range of a temperature wherein the coercive force of the grain after the treatment is not reduced. CONSTITUTION:After an alloy ingot obtained by melting an R2T14B system magnetic alloy is minutely ground, formed in a magnetic field, the formed powder is sintered, the sintered material is ground to a grain size of average 100-500 mum, the ground powder is mixed with a polymer resin and is made aging treatment at the range of a temperature 450-680 deg.C. That is, by grinding the sintered material sintered after the alloy powder is formed in a magnetic field, even the greater grain size crystal grain of the sintered material is also made a one-directional anisotropic grain and high orientation is shown in a magnetic field. By making the grain size of the powder average 100 mum or more, the stress-strain, etc. introduced while being ground is also removed by the aging treatment and coercive force is improved. |
