Dust core and method for producing the same
First Claim
1. A powder magnetic core obtained by compacting an iron-based magnetic powder covered with an insulation film, wherein:
- a saturation magnetization Ms is Ms≧
1.9 T in a 1.6 MA/m magnetic field;
a specific resistance ρ
is ρ
≧
1.5 μ
Ω
m;
a magnetic flux density B2k is B2k≧
1.1 T in a 2 kA/m magnetic field; and
a magnetic flux density B10k is B10k≧
1.6 T in a 10 kA/m magnetic field.
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Accused Products
Abstract
The present invention is characterized in that, in a powder magnetic core obtained by compaction of an iron-based magnetic powder covered with an insulation film, a saturation magnetization Ms is Ms≧1.9 T in a 1.6 MA/m magnetic field; a specific resistance ρ is ρ≧1.5 μΩm; a magnetic flux density B2k is B2k≧1.1 T in a 2 kA/m magnetic field; and a magnetic flux density B10k is B10k≧1.6 T in a 10 kA/m magnetic field. In accordance with the present invention, it has been possible to industrially carry out compacting iron-based magnetic powders under remarkably high compacting pressures. As a result, high-performance powder magnetic cores are obtained which have a high density, and which are good in terms of the specific resistance and magnetic permeability.
26 Citations
26 Claims
-
1. A powder magnetic core obtained by compacting an iron-based magnetic powder covered with an insulation film, wherein:
-
a saturation magnetization Ms is Ms≧
1.9 T in a 1.6 MA/m magnetic field;
a specific resistance ρ
is ρ
≧
1.5 μ
Ω
m;
a magnetic flux density B2k is B2k≧
1.1 T in a 2 kA/m magnetic field; and
a magnetic flux density B10k is B10k≧
1.6 T in a 10 kA/m magnetic field. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A process for producing a powder magnetic core comprising:
-
a coating step of coating an insulation film on a surface of an iron-based magnetic powder;
an applying step of applying a higher fatty acid-based lubricant to an inner surface of a die;
a filling step of filling the iron-based magnetic powder with the insulation film coated into the die with the higher fatty acid-based lubricant applied; and
a forming step of warm pressure compacting the iron-based magnetic powder filled in the die. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
-
-
24. A process for producing a powder magnetic core comprising:
-
a coating step of coating an insulation film on a surface of an iron-based magnetic powder;
an applying step of applying a higher fatty acid-based lubricant to an inner surface of a die;
a filling step of filling the iron-based magnetic powder with the insulation film coated into the die with the higher fatty acid-based lubricant applied; and
a forming step of warm compacting the iron-based magnetic powder filled in the die;
whereby a powder magnetic core obtained is that;
the saturation magnetization Ms is Ms≧
1.9 T in a 1.6 MA/m magnetic field;
the specific resistance ρ
is ρ
≧
1.5 μ
Ω
m;
the magnetic flux density B2k is B2k≧
1.1 T in a 2 kA/m magnetic field; and
the magnetic flux density B10k is B10k≧
1.6 T in a 10 kA/m magnetic field.
-
-
25. A powder magnetic core obtained by:
-
a coating step in which an insulation film containing Fe is coated on a surface of an iron-based magnetic powder;
an applying step of applying a higher fatty acid-based lubricant to an inner surface of a die;
a filling step of filling the iron-based magnetic powder with the insulation film coated into the die with the higher fatty acid-based lubricant applied; and
a forming step of warm compaction of the iron-based magnetic powder filled in the die so that a metallic soap film is formed by a reaction between Fe in the insulation film and the higher fatty acid-based lubricant, wherein;
a saturation magnetization Ms is Ms≧
1.9 T in a 1.6 MA/m magnetic field;
a specific resistance ρ
is ρ
≧
1.5 μ
Ω
m;
a magnetic flux density B2k is B2k≧
1.1 T in a 2 kA/m magnetic field; and
a magnetic flux density B10k is B10k≧
1.6 T in a 10 kA/m magnetic field.
-
-
26. A process for producing a powder magnetic core comprising:
-
a coating step in which an insulation film containing Fe is coated on a surface of an iron-based magnetic powder;
an applying step of applying a higher fatty acid-based lubricant to an inner surface of a die;
a filling step of filling the iron-based magnetic powder with the insulation film coated into the die with the higher fatty acid-based lubricant applied; and
a forming step of warm compaction of the iron-based magnetic powder filled in the die so that a metallic soap film is formed by a reaction between Fe in the insulation film and the higher fatty acid-based lubricant.
-
Specification