| 摘要 |
PURPOSE:To form a magnetic powder of the same shape and the same grain size by evaporation-eliminating a dispersion medium through mixing a non- magnetic powder with a magnetic fluid which ferrite grains are stabilized and dispersed in the dispersion medium. CONSTITUTION:After a graded kaolin is added to a diluted magnetic fluid in which a kerosine is added to a kerosine base magnetic fluid, kneaded by a roll mill. After this is spread on an evaporating tray and dried to sweep away a kerosine smell by an air bath, it is subjected to a heat treatment in a nitrogen air current. After powder heat-treated is cooled down to a room temperature in a nitrogen atmosphere, it is ground by a vibrating mill. Therefore, a magnetic powder of a predetermined grain size and a predetermined magnetic characteristics are obtained. |
