| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide technology for stably obtaining a rare earth permanent magnet which exhibits coercive force higher than a conventional one without dispersion while degradation of residual magnetic flux density is suppressed. <P>SOLUTION: A manufacturing method of R-T-B (R: one type or two or above types of rare earth elements comprising Y, T: one or two or above types of transition metal elements in which Fe or Fe and Co are made indispensable and B: boron) system rare earth permanent magnet is provided with a step for forming powder whose ratio of D50 (D50: Particle size whose cumulative volume ratio becomes 50%) with respect to D99 (D99: Particle size whose cumulative volume ratio becomes 99%) is below 2.99, and a step for sintering an obtained molding body and obtaining a sintered body. Thus, high coercive force of not less than 15kOe and not less than 16kOe and residual magnetic flux density of not less than 13kG are given even if Dy effective for high coercive force is not contained by setting a particle size ratio "D99/D50" to be below 2.99. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
