| 摘要 |
PURPOSE:To rustproof-treating magnetic metal powder providing graphite coating on the powder surfaces, by bringing the metal powder into contact with hydrocarbon gas or water gas and making them react. CONSTITUTION:Powder of Fe, Co, Ni, or alloys of these with a particle diameter of 0.5mu or smaller is used. When a mixed gas of Co and H2 is used, graphite coating effective for preventing the oxidation is formed on the surfaces of the metal powder by bringing the powder into contact under 150-400 deg.C. Or, using methane or ethane, etc., the metal powder is brought into contact under 300-500 deg.C in an H2 current. It is appropriate that the amount of graphite effective for preventing the oxidation should be in the range of 0.5-15wt.% to the metal powder. The magnetic metal films obtained by this method have merits that the lowering of the saturation magnetization sigmaS is very little and the durability for preventing the oxidation is sufficient owing to the fine graphite coating. |
