| 摘要 |
PURPOSE:To produce rare earth-iron-nitrogen compd. magnet powder excellent in oxidation resistance and having high coercive force by providing a copper layer on the surface of rare earth-iron-nitrogen compd. fine powder by electroless plating, furnishing a zinc layer on the copper layer by electroplating and heat-treating the plated fine powder in a specified manner. CONSTITUTION:The rare earth-iron-nitrogen compd. magnet powder contg. Sm alone or the rare earth elements consisting of <=70% of >=1 kind among Y, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu and the balance Sm and having <=5mum grain diameter is brought into contact with a polar org. solvent contg. >=1 kind among copper sulfate, cuprous chloride and cupric chloride to deposit a copper layer having a specified thickness on the surface of the powder. A zinc layer is then formed on the copper layer by electroplating. In this case, the film thickness of zinc is preferably controlled to >=0.04mum and the copper film thickness plus zinc film thickness to <=0.25mum. The magnet powder is then heat-treated at 300-600 deg.C in an inert atmosphere. |
