| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide rare earth-iron-nitrogen based magnet powder having excellent magnetic properties by reducing a nonmagnetic phase of reducing the magnetic properties, and reducing the strain of crystals and the remaining of α-Fe to form into the nuclei of magnetization reversal (nucleation), and to provide a method for inexpensively producing the same by a reduction diffusion process. <P>SOLUTION: The production method comprises: a stage where rare earth oxide powder, iron powder and at least one kind of reducing agent powder selected from alkali metals or the like are mixed in prescribed ratios; a stage where the mixture is heated at 900 to 1,180°C in an inert gas atmosphere; a stage where the obtained reaction product is successively cooled to 20 to 300°C in an inert gas atmosphere; a stage where the inert gas is thereafter exhausted, then, a gaseous mixture comprising ammonia and hydrogen is fed thereto, and the reaction product is heated up in the gas flow, so as to be subjected to nitriding treatment at 350 to 500°C; a stage where the obtained nitriding-treated product is next injected into water, and is subjected to wet treatment, so as to be collapsed; and a stage where the collapsed nitriding-treated product is charged to a pulverizer, so as to be pulverized. <P>COPYRIGHT: (C)2007,JPO&INPIT |
