| 摘要 |
PROBLEM TO BE SOLVED: To solve problems that a soft magnetic powder having an insulation film formed on the surface with a conventional method tends to break the insulation film due to a pressure applied when being press-formed, shows low workability, lowers its electrical resistivity when the insulation film has been broken by the pressure applied when having been press-formed, and consequently increases electric power loss due to an eddy current. SOLUTION: This production method comprises the steps of: placing an Mg-containing metallic evaporation material in a treatment chamber 10; heating the evaporation material to vaporize it and form an atmosphere of the metallic vapor in the treatment chamber; charging the soft magnetic powder to the treatment chamber, which is in a state of being kept at a lower temperature than that in the treatment chamber; selectively depositing the metallic evaporation material on the surface of the soft magnetic powder by using a temperature difference between the atmosphere in the treatment chamber and the soft magnetic powder, while moving the soft magnetic powder in the treatment chamber; and subsequently heating the soft magnetic powder having the metallic evaporation material depositing on the surface at a predetermined temperature. COPYRIGHT: (C)2008,JPO&INPIT
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