| 摘要 |
PURPOSE:To stably control the composition for bearing the specific magnetic characteristics by a method wherein the rough particle side of crushed powder is circularly crushed in the fine crushing step of an alloy powder for controlling the mean particle diameter distribution within specific range. CONSTITUTION:Within the title permanent magnet manufactured by crush- molding and baking the melt-cast ingot mainly comprising rare earth element-Fe- boron, the mean crystalline particle diameter of a sintered body is to be 3.5mum-10mum, the content probability of the particles in the sintered body in diameter exceeding 10mum is not to exceed 10% while the value of Hk/proper coercive force is to be 95%. On the other hand, within the manufacturing method of this mean particle diameter of a material powder before the molding step is to be 3-7mum, the content probability of the particles in diameter exceeding 9mum is not to exceed 10% furthermore, rough particles in diameter exceeding 10mum is to be classified and circularly crushed into alloy powder. Through these procedures, the title high performance permanent magnet having so high coercive force and Hk can be manufactured. |
