| 摘要 |
PURPOSE:To provide alloy powder having improved magnetic characteristics suitable for resin magnets, by introducing nitrogen effective for the improvement of magnetic characteristics of sintered magnet alloy only into the surface layer of the alloy powder. CONSTITUTION:An alloy is dry-milled within atmosphere consisting of or containing nitrogen. Preferably, the alloy subjected to such treatment contains rare-earth elements and iron but substantially no nitrogen and has an average grain size of 100mum or more, so that the surface of the alloy powder obtains identical composition to that of the central principal phase thereof through the treatment. Such alloy is subjected to drymilling within atmosphere consisting of or containing nitrogen, whereby powder thus produced obtains a coercive force improving layer covering the central principal phase. The atmosphere preferably consists of nitrogen or of nitrogen and an inert gas. The dry-milling is continued until an average grain size of 1-50mum is obtained, so that alloy powder having improved magnetic characteristics can be obtained. |
