| 摘要 |
PURPOSE: To provide a method of manufacturing an R-Fe-B sintered permanent magnet in which the dimensional accuracy and the productivity of a molded body are enhanced, whose shape is thin and small and which has an excellent magnetic characteristic. CONSTITUTION: A principal phase-based alloy powder which has been crushed fine and a liquid phase-based alloy powder whose particle size has been made comaratively large in order to prevent oxidation are mixed individually or at a prescribed mixing ratio, a binder which is composed of methycellulose, polyacrylamide and polyvinyl alcohol alone or as a mixture and of water is added and kneaded, and a slurrylike substance is formed. The slurry is changed into a granulated powder whose average particle size is 20 to 400μm, whose fluidity is high and whose particle shape is spherical, oxidation during a spray granulation process is suppressed, and the granulated powder is changed into a sintered magnet. Thereby, it is possible to obtain an R-Fe-B sintered permanent magnet in which the lubricant property of the binder itself is excellent, the fluidity of a pulverulent body is enhanced remarkably, a molding cycle is enhanced, the variation in the density of a molded body is reduced, the life of a molding machine is not lowered and whose dimensional accuracy after a sintering operation is excellent. |
