| 摘要 |
PURPOSE:To produce, with good productivity, a cylindrical rare earth metal sintered magnet, especially a thin magnet and a continuous length magnet, whose magnetic performance is high, by a method wherein, after a magnet composition consisting of magnet powder obtained by pulverizing a cast ingot mainly composed of rare earth metal, Fe and B and an organic binder has been extrusion-molded in a magnetic field, the molded material is sintered. CONSTITUTION:A magnetic compound consists of 90-97 wt.% of magnet powder obtained by pulverizing a cast ingot mainly composed of R (a rare earth metal), Fe and B and consists of 3-10 wt.% of an organic binder; after this magnet composition has been mixed, kneaded and then granulated, it is extrusion-molded in a magnetic field. A metal mold during the molding process is set at a temperature of 220 deg.C; the cooling operation is executed forcibly at an outlet of the metal mold. After the binder has been removed from the molded material, this material is sintered in a gas of Ar at 1000-1500 deg.C; after that, the material is cooled rapidly; if necessary, the material is furthermore treated by an ageing process; a magnet is completed. At an extrusion- molding machine, an electromagnetic coil 7 to impress the magnetic field is installed at the outside of the metal mold. |
