Patent ID: 6554913
Filing Date: 2003-04-29
Classification: H01F,Y10S,Y10T

Abstract:
A method of manufacturing magnetic powder comprising:milling a ribbon-shaped magnetic material, said ribbon-shaped magnetic material obtained by the sub-method comprising: colliding a molten alloy of a magnetic material to a circumferential surface of a rotating cooling roll so as to cool and then solidify the molten alloy; and expelling gas entered between the circumferential surface of the cooling roll and a puddle of the molten alloy with gas expelling means provided on the circumferential surface of the cooling roll defined by gas flow passages, said gas flow passages having an average width of 0.5 -90 &mgr;m to prevent the molten alloy from entering the gas flow passages, wherein when an average pitch of these gas flow passages is defined as P&mgr;m and an average particle size of the magnetic powder is defined as D&mgr;m, a relationship represented by a formula P