| 摘要 |
PURPOSE:To provide a magnetic metal powder having a surface coating film of high insulation properties formed and a metal powder compression magnetic core providing a permeability which is flat till high frequencies by forming a coating film of a phosphate containing boron on the surface of each particle. CONSTITUTION:An amorphous alloy assumes a film or powder state when it is quenched very rapidly from its molten state. For instance, an amorphous magnetic alloy powder has formed on the particle surface thereof a phosphate coating film containing boron. To form the phosphate coating film, the amorphous magnetic alloy powder is dipped in a solution in which boric acid and phosphate were dissolved, and is subjected to a short-time treatment at a comparatively high temperature. The amorphous magnetic alloy powder having been completed in the surface treatment is then powder compression molded into a predetermined magnetic core shape. At that time, a small amount of glass or synthetic resin (polyimide) may be added, for instance, to an extent of 20wt.%, as a binder. Alternatively, a small amount of lubricant can be added to enhance the powder compression molding properties, in which a binder need not be used. The magnetic powder is thus improved in its properites due to the surface phosphate coating film of high insulation properties. |
