Soft Magnetic Material, Compressed Powder Magnetic Core and Method for Producing Compressed Powder Magnetic Core

• US 20070290161A1
• Filed: 08/31/2005
• Published: 12/20/2007
• Est. Priority Date: 09/01/2004
• Status: Active Grant

• Current Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Nishioka, Takao, Hirose, Kazuhiro, Tokuoka, Terukazu, Sawada, Kouhei, Toyoda, Hiruhisa
• Granted Patent: US 7,678,174 B2
• Time in Patent Office: Days
• US Class Current: 252/62.54
• CPC Class Codes: B22F 1/10 Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
• CPC Class Codes: B22F 1/105 containing inorganic lubricating or binding agents, e.g. metal salts
• CPC Class Codes: B22F 1/16 Metallic particles coated with a non-metal coated with lubricating or binding agents or with organic material B22F1/10
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/02 Compacting only
• CPC Class Codes: H01F 1/24 the particles being insulated
• CPC Class Codes: H01F 3/08 made from powder powder coatings on sheets H01F3/02; on strips or ribbons H01F3/04; on wires H01F3/06
• CPC Class Codes: H01F 41/0246 Manufacturing of magnetic circuits by moulding or by pressing powder magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36

Abstract

A soft magnetic material has an iron based powder that has an insulating coating on the surface and an ester wax. The ester wax is added in an amount not less than 0.02% by weight and not more than 0.6% by weight in relation to the soft magnetic material. Consequently, seizure between a metal mold and a material to be molded at the time of molding can be suppressed and the arising of a black residue can be prevented.

Claims

1. :

A soft magnetic material comprising;

an iron-based powder that has an insulating coating on its surfaces; and

at least 1 type of wax that comprises an ester wax;

at least 0.02% by weight and no more than 0.6% by weight of said wax that comprises said ester wax.

2. :

The soft magnetic material according to claim 1, wherein the average particle size of said wax that comprises said ester wax is at least 0.5 μ

m and no more than the average particle size of said iron based powder that has said insulating coating.

3. :

The soft magnetic material according to claim 1, wherein the melting point of said wax that comprises said ester wax is no more than 100°

C.

4. :

The soft magnetic material according to claim 1, wherein the viscosity upon melting of said wax that comprises said ester wax is no more than 15 mPa·

s.

5. :

The soft magnetic material according to claim 1, further comprising at least 0.0005% by weight and no more than 0.1% by weight of a solid lubricant that exhibits lubrication by exfoliating in layers.

6. :

The soft magnetic material according to claim 5, wherein the particle size of said solid lubricant is no more than 1.5 μ

m.

7. :

The soft magnetic material according to claim 5, wherein said solid lubricant is a metal soap.

8. :

The soft magnetic material according to claim 1, further comprising at least 1 resin selected from the group consisting of thermoplastic resins, non-thermoplastic resins, thermosetting resins and non-thermosetting resins.

9. :

A compressed powder magnetic core manufactured by using the soft magnetic material according to claim 1 and having a density of at least 7.3 g/cm³.

10. :

A method of manufacturing a compressed powder magnetic core, comprising the steps of;

producing a molded body by compression molding the soft magnetic material according to claim 1 utilizing a metal mold; and

setting a temperature of said soft magnetic material for said molding

below the melting point of said wax that comprises said ester wax and the temperature of said metal mold set so that it is at or above the temperature at which said wax that comprises said ester wax exists in a liquid state at the interface of said metal mold and said soft magnetic material.

11. :

The method of manufacturing a compressed powder magnetic core according to claim 10, further comprising the step of carrying out heat treatment of said molded body at or above the decomposition temperature of said wax that comprises said ester wax in an air atmosphere.