| 摘要 |
To improve the performance of a rare-earth magnet, it is effective to use a low-oxidized powder having a small grain size. One objective of the present invention is to provide a method for manufacturing a sintered rare-earth magnet having a magnetic anisotropy, in which a very active powder having a small grain size can be safely used in a low-oxidized state. Another objective is to provide a method capable of efficiently manufacturing products having various shapes. In a weighing and loading section 41 and a high-density loading section 42, a fine powder as a material of the sintered rare-earth magnet having a magnetic anisotropy is loaded into a mold until its density reaches a predetermined level. Then, in a magnetic orientation section 43, the fine powder is oriented by a pulsed magnetic field. Subsequently, the fine powder is not compressed but immediately sintered in a sintering furnace 44. The present method enables the mass-producing machine to be simple in its operation and its housing to be accordingly smaller, so that it will be possible to eliminate the danger of oxidization or burning of the powder, which has been a serious problem for a conventional method that uses a large-scale die-pressing machine. Furthermore, the manufacturing efficiency can be improved by using a multi-cavity mold for manufacturing a sintered rare-earth magnet having an industrially important shape, such as a plate magnet or an arched plate magnet. |
