| 摘要 |
PURPOSE:To achieve with a simple manufacture a magnetic substance of high electric resistivity which has less loss for high-frequency driving, coating the high-permeability grain surface of either iron or iron alloy with a ultrafine metal powder, press molding this, and thereafter sintering the press molded object. CONSTITUTION:An ultrafine metal powder, e.g., grains 2 having a grain diameter of 200-300Angstrom , is applied on the surface of the metal grains 1 of either iron or iron alloy which are provided with high permeability, and after the coated metal grains are press-molded into an object of any shape, the molded object is sintered. Because of the extremely large superficial area per unit mass of the ultrafine metal powder 2, there is existing an oxide film as dense and stable electrical insulation. This is uniformly distributed on the grain boundary of the high-permeability magnetic powder 1 to be press-molded, thereby forming the magnetic powder before molding which has high resistivity due to the coating oxide film. Then, the magnetic powder is sintered, forming the intended sintered magnetic substance. |
