Powdered iron core magnetic devices
AssigneeGeneral Electric Company
InventorsTrasimond A. Soileau, Lawrence W. Speaker
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Abstract
A compacted powdered iron core utilizes iron powder in the 0.002 to 0.006 mean particle size range which is first coated with an alkali metal silicate and then overcoated with a silicone resin polymer. The treated powder is compressed to approximately 94% of theoretical density and then annealed at approximately 600.degree. C. This results in a core component characterized by overall core losses as low as in conventional laminated cores in A.C. operation.
Claims20
A magnetic core comprising densely packed iron particles having a coating of an alkali metal silicate insulating material and an overcoating of a polymer film selected from the group consisting of silicones, polyimides, fluorocarbons and acrylics, said coating and overcoating providing substantial insulation between particles.
A compacted powdered iron magnetic core component for use in A.C. electrical devices comprising:
- iron powder consisting of particles sized less than 0.05 inch prior to compaction,
- the particles of said powder having been coated with alkali metal silicate, overcoated with a polymer film selected from the group consisting of silicones, polyimides, fluorocarbons and acrylics providing insulation between particles, and compacted to at least 90% of theoretical iron density, and
- the so formed compact having been annealed after said compaction and exhibiting relatively low hysteresis losses together with relatively low eddy current losses.
A method of making a powdered iron magnetic core component for use in A.C. electrical devices comprising:
- selecting iron powder having particles sized less than 0.05 inch in diameter,
- mixing an aqueous solution of alkali metal silicate into said powder,
- drying the powder,
- mixing a silicone resin dissolved in an organic solvent into said powder,
- drying the powder to allow the resin to form a thin overcoat on the particles,
- and pressing the powder to the desired shape for the core component.
Dependencies are inferred from the claim text.