| 摘要 |
PURPOSE:To obtain a bonded magnet whose oxidation-resistant property is excellent by a method wherein a film of an organic high polymer is formed, by a plasma polymerization operation, on the surface of an R2T14B-based alloy powder which is composed of rare-earth elements R including yttrium, a transition metal T and boron B. CONSTITUTION:An R2T14B-based alloy powder which has been degreased and cleaned is placed inside a reaction tube provided with required electrodes; the inside of the reaction tube is set to 10<-3>Torr or lower; after that, an organic substance is introduced in such a way that the inside of the tube becomes a required pressure; a glow discharge is executed; the alloy powder covered with an organic high polymer is obtained. As the organic substance to be used, a compound which does not have a functional group to form a high polymer may be used; e.g. a compound having a vinyl group, 4-methylpyridine, furan, n-hexane, tetrafluoromethane, dimethylsulfoxide and the like can be enumerated; normally, they are introduced into the reaction tube as a vapor; they may be introduced as a liquid/gaseous colloid. As an output of the glow discharge, about 10 to 300W is appropriate. The obtained high-polymer film is provided with a sufficient bonding property and reliability as an oxidation-resistant film as it is. However, it is preferable to heat-treat the film at a melting point or lower of said high polymer. |
