| 摘要 |
PURPOSE:To improve oxidation-resistant properties of a permanent magnet and improve its practical performance by a method wherein a specific content of metal or alloy powder whose melting point is specified is added to rare-earth metal compound powder whose basic components are rare-earth element, iron and boron and the mixed powder is compressed and molded at a temperature not higher than the specified melting point. CONSTITUTION:The basic components of magnetic powder are rare-earth metal, iron and boron. Its particle size is not larger than 80mesh (177mum). Then metal or alloy powder whose melting point is not higher than 900 deg.C is prepared as binder. The recommended content of the binder is 10vol.%-50vol.%. If the content is lower than 10vol.%, although the magnetic performance is improved, the mechanical strength is degraded and the practical performance is degraded. Moreover, as the surface coating layers of the magnetic powder particles become thin, the degradation of rust-resistant properties becomes a problem. On the other hand, if the content is higher than 50vol.%, the magnetic performance is degraded and the characteristics of the permanent magnet can not be exhibited. Therefore, 50vol.% is the maximum. |
