| 摘要 |
PURPOSE: To enhance oxidation resistance by a method wherein the prescribed quantity of methyl cellulose and water or methanol is added to rare earth containing alloy powder, the mixture is slurried by agitating it at a specific low temperature, and the slurry is powdered by spray-drying using a spray drier, and a binder is uniformly coated on the powder. CONSTITUTION: A binder, consisting of methyl cellulose of 0.1 to 0.4wt.% and water or methanol of 20 to 50wt.%, is added to rare earth containing alloy powder, the mixture is slurried by agitating in the temperature range of 0 to 15 deg.C. This slurry is sprayed and dried by a spray drying device, and a binder is uniformly coated on the obtained powder. Lastly, the powder on which 300 hours have passed is molded into the specific form using a pressing machine in a magnetic field, and the molded material is heated in a vacuum and hydrogen atmosphere to remove the binder. Subsequently, a sintering treatment is conducted in a vacuum atmosphere at 1100 deg.C, and after sintering, the sintered material is cooled by introducing Ar gas, an aging treatment is conducted, and an anisotropic sintered body is obtained. As a result, a rare-earth magnet, having high oxidation resisting property, can be obtained. |
