Composite soft magnetic powdery material and magnetically biasing permanent magnetic core containing same

Abstract

The present invention relates to a composite soft magnetic powdery material. The composite soft magnetic powdery material includes a strong permanent magnetic powder and a Fe-based soft magnetic powder. The mixing ratio of the Fe-based soft magnetic powder to the strong permanent magnetic powder is from 5:5 to 9:1. The composite soft magnetic powdery material has a magnetic permeability of from 5 to 50.

1 . A composite soft magnetic powdery material comprising:
 a strong permanent magnetic powder; and   a Fe-based soft magnetic powder, wherein the mixing ratio of said Fe-based soft magnetic powder to said strong permanent magnetic powder is from 5:5 to 9:1,   wherein said composite soft magnetic powdery material has a magnetic permeability of from 5 to 50.   
   
   
       2 . The composite soft magnetic powdery material according to  claim 1  wherein said strong permanent magnetic powder has an intrinsic coercive force of 5 kOe or more and a Curie temperature (Tc) of 300° C. or more. 
   
   
       3 . The composite soft magnetic powdery material according to  claim 1  wherein said strong permanent magnetic powder includes rare-earth permanent magnetic powder. 
   
   
       4 . The composite soft magnetic powdery material according to  claim 3  wherein said rare-earth permanent magnetic powder is selected from a group consisting of NdFeB series, SmCo series and SmFeN series. 
   
   
       5 . The composite soft magnetic powdery material according to  claim 1  wherein said Fe-based soft magnetic powder is selected from a group consisting of carbonyl iron powder, atomizing iron powder, electrolytic iron powder, Fe—Si alloy powder, Fe—Ni alloy powder, Fe—Si—Al alloy powder, Fe—Si—Cr alloy powder, and Fe-based amorphous power. 
   
   
       6 . The composite soft magnetic powdery material according to  claim 1  wherein said composite soft magnetic powdery material has a specific resistance of 0.1 Ω•cm or more. 
   
   
       7 . The composite soft magnetic powdery material according to  claim 1  wherein said Fe-based soft magnetic powder and said strong permanent magnetic powder have substantially identical shapes. 
   
   
       8 . The composite soft magnetic powdery material according to  claim 7  wherein said Fe-based soft magnetic powder and said strong permanent magnetic powder have spherical or nearly spherical shapes. 
   
   
       9 . The composite soft magnetic powdery material according to  claim 7  wherein said Fe-based soft magnetic powder and said strong permanent magnetic powder have maximum particle size equal to or less than 100 μm, and average particle size between 5 μm and 50 μm. 
   
   
       10 . A magnetically biasing magnetic core having a magnetic permeability of from 5 to 50, said magnetically biasing magnetic core comprising:
 a composite soft magnetic powdery material comprising a strong permanent magnetic powder and a Fe-based soft magnetic powder, wherein the mixing ratio of said Fe-based soft magnetic powder to said strong permanent magnetic powder is from 5:5 to 9:1; and   at least one additive.   
   
   
       11 . The magnetically biasing magnetic core according to  claim 10  wherein said strong permanent magnetic powder has an intrinsic coercive force of 5 kOe or more and a Curie temperature (Tc) of 300° C. or more. 
   
   
       12 . The magnetically biasing permanent magnetic core according to  claim 10  wherein said strong permanent magnetic powder includes rare-earth permanent magnetic powder. 
   
   
       13 . The magnetically biasing magnetic core according to  claim 12  wherein said rare-earth permanent magnetic powder is selected from a group consisting of NdFeB series, SmCo series and SmFeN series. 
   
   
       14 . The magnetically biasing magnetic core according to  claim 10  wherein said Fe-based soft magnetic powder is selected from a group consisting of carbonyl iron powder, atomizing iron powder, electrolytic iron powder, Fe—Si alloy powder, Fe—Ni alloy powder, Fe—Si—Al alloy powder, Fe—Si—Cr alloy powder, and Fe-based amorphous power. 
   
   
       15 . The magnetically biasing magnetic core according to  claim 10  wherein said magnetically biasing magnetic core has a specific resistance of 0.1 Ω•cm or more and a density of 5.5 g/cm 3  or more. 
   
   
       16 . The magnetically biasing magnetic core according to  claim 10  wherein said Fe-based soft magnetic powder and said strong permanent magnetic powder have spherical or nearly spherical shapes. 
   
   
       17 . The magnetically biasing magnetic core according to  claim 16  wherein said Fe-based soft magnetic powder and said strong permanent magnetic powder have maximum particle size equal to or less than 100 μm, and average particle size between 5 μm and 50 μm. 
   
   
       18 . The magnetically biasing magnetic core according to  claim 10  wherein said at least one additive includes an insulating agent and/or an organic adhesive. 
   
   
       19 . The magnetically biasing magnetic core according to  claim 18  wherein said organic adhesive is selected from polypropylene resin, 6-nylon resin, 12-nylon resin, polyethylene resin, polyimide resin, phenolic resin or epoxy resin. 
   
   
       20 . The magnetically biasing magnetic core according to  claim 10  wherein said magnetically biasing magnetic core has been subject to magnetization.