| 摘要 |
PROBLEM TO BE SOLVED: To enable a magnetic material to be baked at a low temperature and ground down in a shorter time by a method wherein the magnetic material is composed of iron sesquinoxide (Fe2O3), ZnO, CuO, and NiO as main components, and a specific weight of Si is added to the magnetic material. SOLUTION: Ferrite material composed of FeO, ZnO, NiO, and CuO which are weighed as main components is mixed and ground by the use of a wet-type inner circulation medium agitation-type mill using silicon nitride balls as medium beads. Thereafter, the ground material is calcinated and ground into oxide magnetic material by the use of a wet-type inner circulation medium agitation- type mill using silicon nitride balls as medium beads. At this point, 0.010 to 0.112 wt.% Si is added to the oxide magnetic material by wear and tear of the medium beads. The core of a bulk-type coil is formed through such a manner where binder is added to the above oxide magnetic material for the formation of granules, and the granules are molded, formed, and baked in the air. |
