| 摘要 |
PURPOSE:To safely and stably produce raw material powder for a permanent magnet material by coarsely crushing specifically composed raw material Fe-B-R ingots, occluding H2 therein to form coarsely crushed powder and pulverizing the powder by a supersonic inert gas contg. O2 at a specified ratio. CONSTITUTION:The ingots essentially consisting of 12-20atom% R (at least 1 kind among Nd, Pr, Dy, Ho, and Tb or further at least 1 kind among La, Ce, Sm, Gd, Er, Eu, Tm, Yb, Lu, and Y), 4-20atom% B, 65-81atom% Fe are crushed and H2 is occluded therein to cause natural decay and to form the coarsely crushed powder having 500-10mu average grain size. The coarsely crushed powder is then injected into a pulverizing chamber for gaseous flow pulverization using the supersonic inert gas contg. 50-6,000ppm O2 and is thereby pulverized to the fine raw material powder having 1.5-5mu average grain size. The fine powder is molded to a required shape and size by orientation in a magnetic field; thereafter, the molding is sintered in a vacuum and is allowed to cool. The molding is further subjected to an aging treatment in an Ar atmosphere, by which the permanent magnet material is obtd. |
