| 摘要 |
PURPOSE:To improve the energy product of an anisotropic permanent magnet and also to contrive reduction in cost by dispensing with an ingot-powdering process by a method wherein, after the molten alloy, which is adjusted into the prescribed component and composition and quench-solidified into amorphous fine powder, an annealing operation is performed at a specific temperature, and the fine powder is compression- molded. CONSTITUTION:The molten alloy, which is adjusted in the prescribed component and composition, is quench-solidified at the cooling speed of 10<5> deg./sec. or above, and the amorphous fine powder, desirably the fine powder of 150 mum or less in grain diameter, is obtained. Especially magnetic alloy powders of Rem-Co and Rem-Fe-B base and the like are considered suitable. Then, the isotropic fine powder, in which polelike crystal is grown from the powder surface toward the center, is obtained by performing an annealing operation on the amorphous fine powder obtained as above at the temperature at which the fine powder will be crystallized. At this time, 300-700 deg.C is considered suitable, as the recrystallization and annealing temperature. Subsequently, after said fine powder has been oriented in a rotating magnetic field as occasion demands, it is compression-molded, a sintering treatment is performed thereon, and the isotropic sintered magnet having a large energy product is formed. |
