Method for Producing Soft Magnetic Metal Powder Coated With Mg-Containing Oxide Film and Method for Producing Composite Soft Magnetic Material Using Said Powder

• US 20080003126A1
• Filed: 09/06/2005
• Published: 01/03/2008
• Est. Priority Date: 09/06/2004
• Status: Abandoned Application

• Current Assignee: Diamet Corporation (Mitsubishi Materials Corporation)
• Original Assignee: Mitsubishi Materials PMG Corp (Mitsubishi Materials Corporation)
• Inventors: Nakayama, Ryoji, Watanabe, Muneaki, Uozumi, Gakuji
• Application Number:
  US11/574,655
• Publication Number:
  US 20080003126A1
• Time in Patent Office: Days
• US Class Current: 419/35
• CPC Class Codes: B22F 1/06 Metallic powder characterised by the shape of the particles nanosized particles B22F1/054
• CPC Class Codes: B22F 1/145 Chemical treatment, e.g. passivation or decarburisation
• 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 2201/02 Nitrogen
• CPC Class Codes: B22F 2201/03 Oxygen
• CPC Class Codes: B22F 2201/11 Argon
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/02 Compacting only
• CPC Class Codes: B22F 3/10 Sintering only
• CPC Class Codes: C22C 33/02 by powder metallurgy working metallic powder B22F
• CPC Class Codes: C22C 38/00 Ferrous alloys, e.g. steel alloys cast-iron alloys C22C37/00
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/06 containing aluminium
• CPC Class Codes: C22C 38/08 containing nickel C22C38/105 takes precedence
• CPC Class Codes: C22C 38/10 containing cobalt
• CPC Class Codes: C22C 38/12 containing tungsten, tantalum, molybdenum, vanadium, or niobium
• CPC Class Codes: C22C 38/18 containing chromium
• CPC Class Codes: H01F 1/33 mixtures of metallic and non-metallic particles; metallic particles having oxide skin
• 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 method for producing a soft magnetic metal powder coated with a Mg-containing oxide film, comprising the steps of adding and mixing a Mg powder with a soft magnetic metal powder which has been subjected to heating treatment in an oxidizing atmosphere at a temperature of 40 to 500° C. to obtain a mixed powder, and heating the mixed powder at a temperature of 150 to 1,100° C. in an inert gas or vacuum atmosphere under a pressure of 1×10⁻¹² to 1×10⁻¹ MPa, while optionally tumbling; and a method for producing a composite soft magnetic material from the soft magnetic metal powder coated with a Mg-containing oxide film.

Claims

1. A method for producing a soft magnetic metal powder coated with a Mg-containing oxide film, comprising the steps of:

subjecting a soft magnetic metal powder to oxidation treatment to provide a raw powder material;

adding and mixing a Mg powder with said raw powder material to obtain a mixed powder; and

heating said mixed powder at a temperature of 150 to 1,100°

C. in an inert gas or vacuum atmosphere under a pressure of 1×

10<sup>−

12</sup> to 1×

10<sup>−

1</sup> MPa, thereby obtaining a soft magnetic metal powder coated with a Mg-containing oxide film.

2. The method according to claim 1, further comprising the step of heating said soft magnetic metal powder coated with a Mg-containing oxide film in an oxidizing atmosphere at a temperature of 50 to 400°

C.

3. The method according to claim 1, wherein said step of subjecting a soft magnetic metal powder to oxidation treatment comprises heating a soft magnetic metal powder in an oxidizing atmosphere at a temperature of 50 to 500°

C.

13. The method according to claim 1, wherein said heating in a vacuum or inert gas atmosphere is performed while tumbling.

14. The method according to claim 1, wherein said soft magnetic metal powder is an iron powder, an insulated-iron powder, Fe—

Al iron-based soft magnetic alloy powder, Fe—

Ni iron-based soft magnetic alloy powder, Fe—

Cr iron-based soft magnetic alloy powder, Fe—

Si iron-based soft magnetic alloy powder, Fe—

Si—

Al iron-based soft magnetic alloy powder, Fe—

Co iron-based soft magnetic alloy powder, Fe—

Co—

V iron-based soft magnetic alloy powder, or Fe—

P iron-based soft magnetic alloy powder.

15. A method for producing a raw powder material defined in claim 1 comprising a soft magnetic powder which has been subjected to oxidation treatment, which comprises the steps of:

adding and mixing a Si powder with an Fe—

Si iron-based soft magnetic powder or Fe powder, followed by heating in a non-oxidizing atmosphere to obtain an Fe—

Si iron-based soft magnetic powder having a high-concentration Si diffusion layer which has a Si concentration higher than the Fe—

Si iron-based soft magnetic powder or Fe powder; and

subjecting said Fe—

Si iron-based soft magnetic powder having a high-concentration Si diff layer to oxidizing treatment, thereby obtaining a surface-oxidized, Fe—

Si iron-based soft magnetic raw powder material having an oxide layer formed on the high-concentration Si diffusion layer.

16. A method for producing a composite soft magnetic material having excellent resistivity and mechanical strength, comprising the steps of:

subjecting a soft magnetic metal powder coated with a Mg-containing oxide film produced by the method of claim 1 to press molding; and

sintering the resultant at a temperature of 400 to 1,300°

C.

17. A method for producing a composite soft magnetic material having excellent resistivity and mechanical strength, comprising the steps of:

mixing an organic insulating material, inorganic insulating material or a mixed material of an organic insulating material and an inorganic insulating material with a soft magnetic metal powder coated with a Mg-containing oxide film produced by the method of claim 1, followed by powder compaction; and

sintering the resultant at a temperature of 500 to 1,000°

C.

18. A composite soft magnetic material exhibiting excellent resistivity and mechanical strength, which is produced by the method of claim 16.

19. An electromagnetic circuit component comprising a composite soft magnetic material of claim 18.

20. The electromagnetic circuit component according to claim 19, which is a magnetic core, motor core, generator core, solenoid core, ignition core, reactor core, transcore, choke coil core or magnetic sensor core.

21. An electric appliance having integrated therein an electromagnetic circuit component of claim 20.

4. A raw powder material for producing a soft magnetic metal powder coated with a Mg-containing oxide film, provided by subjecting a soft magnetic metal powder to oxidation treatment.

5. A method for producing a soft magnetic metal powder coated with a Mg-containing oxide film, comprising the steps of:

adding and mixing a Mg powder with a soft magnetic metal powder to obtain a mixed powder; and

heating said mixed powder at a temperature of 150 to 1,100°

C. in an inert gas or vacuum atmosphere under a pressure of 1×

10<sup>−

12</sup> to 1×

10<sup>−

1</sup> MPa, followed by heating in an oxidizing atmosphere at a temperature of 50 to 400°

C. to effect oxidation treatment, thereby obtaining a soft magnetic metal powder coated with a Mg-containing oxide film.

28. The method according to claim 5, wherein said heating in a vacuum or inert gas atmosphere is performed while tumbling.

29. The method according to claim 5, wherein said soft magnetic metal powder is an iron powder, an insulated-iron powder, Fe—

Al iron-based soft magnetic alloy powder, Fe—

Ni iron-based soft magnetic alloy powder, Fe—

Cr iron-based soft magnetic alloy powder, Fe—

Si iron-based soft magnetic alloy powder, Fe—

Si—

Al iron-based soft magnetic alloy powder, Fe—

Co iron-based soft magnetic alloy powder, Fe—

Co—

V iron-based soft magnetic alloy powder, or Fe—

P iron-based soft magnetic alloy powder.

30. A method for producing a raw powder material defined in claim 5 comprising a soft magnetic powder which has been subjected to oxidation treatment, which comprises the steps of:

adding and mixing a Si powder with an Fe—

Si iron-based soft magnetic powder or Fe powder, followed by heating in a non-oxidizing atmosphere to obtain an Fe—

Si iron-based soft magnetic powder having a high-concentration Si diffusion layer which has a Si concentration higher than the Fe—

Si iron-based soft magnetic powder or Fe powder; and

subjecting said Fe—

Si iron-based soft magnetic powder having a high-concentration Si diff layer to oxidizing treatment, thereby obtaining a surface-oxidized, Fe—

Si iron-based soft magnetic raw powder material having an oxide layer formed on the high-concentration Si diffusion layer.

31. A method for producing a composite soft magnetic material having excellent resistivity and mechanical strength, comprising the steps of:

subjecting a soft magnetic metal powder coated with a Mg-containing oxide film produced by the method of claim 5 to press molding; and

sintering the resultant at a temperature of 400 to 1,300°

C.

32. A method for producing a composite soft magnetic material having excellent resistivity and mechanical strength, comprising the steps of:

mixing an organic insulating material, inorganic insulating material or a mixed material of an organic insulating material and an inorganic insulating material with a soft magnetic metal powder coated with a Mg-containing oxide film produced by the method of claim 5, followed by powder compaction; and

sintering the resultant at a temperature of 500 to 1,000°

C.

6. A method for producing a soft magnetic powder coated with a Mg—

Si-containing oxide film, comprising the steps of;

forming an oxide film on a surface of a soft magnetic powder to provide an oxide-coated soft magnetic powder;

adding and mixing a silicon monoxide powder with said oxide-coated soft magnetic powder;

performing heating in a vacuum atmosphere at a temperature of 600 to 1,200°

C. during or following said mixing of a silicon monoxide powder with said oxide-coated soft magnetic powder;

adding and mixing a Mg powder with the resultant; and

performing heating in a vacuum atmosphere at a temperature of 400 to 800°

C. during or following said mixing of an Mg powder with the resultant.

9. The method according to claim 6, wherein said step of forming an oxide film on a surface of a soft magnetic powder comprises heating a soft magnetic powder in an oxidizing atmosphere at a temperature of room temperature to 500°

C.

10. The method according to claim 9, wherein said silicon monoxide is added in an amount of 0.01 to 1% by mass, and said Mg powder is added in an amount of 0.05 to 1% by mass.

11. The method according to claim 10, wherein said vacuum atmosphere is an atmosphere under a pressure of 1×

10<sup>−

12</sup> to 1×

10<sup>−

1</sup> MPa.

33. The method according to claim 6, wherein said heating in a vacuum or inert gas atmosphere is performed while tumbling.

34. The method according to claim 6, wherein said soft magnetic metal powder is an iron powder, an insulated-iron powder, Fe—

Al iron-based soft magnetic alloy powder, Fe—

Ni iron-based soft magnetic alloy powder, Fe—

Cr iron-based soft magnetic alloy powder, Fe—

Si iron-based soft magnetic alloy powder, Fe—

Si—

Al iron-based soft magnetic alloy powder, Fe—

Co iron-based soft magnetic alloy powder, Fe—

Co—

V iron-based soft magnetic alloy powder, or Fe—

P iron-based soft magnetic alloy powder.

35. A method for producing a raw powder material defined in claim 6 comprising a soft magnetic powder which has been subjected to oxidation treatment, which comprises the steps of:

adding and mixing a Si powder with an Fe—

Si iron-based soft magnetic powder or Fe powder, followed by heating in a non-oxidizing atmosphere to obtain an Fe—

Si iron-based soft magnetic powder having a high-concentration Si diffusion layer which has a Si concentration higher than the Fe—

Si iron-based soft magnetic powder or Fe powder; and

subjecting said Fe—

Si iron-based soft magnetic powder having a high-concentration Si diff layer to oxidizing treatment, thereby obtaining a surface-oxidized, Fe—

Si iron-based soft magnetic raw powder material having an oxide layer formed on the high-concentration Si diffusion layer.

36. A method for producing a composite soft magnetic material having excellent resistivity and mechanical strength, comprising the steps of:

subjecting a soft magnetic metal powder coated with a Mg-containing oxide film produced by the method of claim 6 to press molding; and

sintering the resultant at a temperature of 400 to 1,300°

C.

37. A method for producing a composite soft magnetic material having excellent resistivity and mechanical strength, comprising the steps of:

mixing an organic insulating material, inorganic insulating material or a mixed material of an organic insulating material and an inorganic insulating material with a soft magnetic metal powder coated with a Mg-containing oxide film produced by the method of claim 6, followed by powder compaction; and

sintering the resultant at a temperature of 500 to 1,000°

C.

7. A method for producing a soft magnetic powder coated with a Mg—

Si-containing oxide film, comprising the steps of;

forming an oxide film on a surface of a soft magnetic powder to provide an oxide-coated soft magnetic powder;

adding and mixing a silicon monoxide powder and a Mg powder with said oxide-coated soft magnetic powder; and

performing heating in a vacuum atmosphere at a temperature of 400 to 1,200°

C. during or following said mixing of a silicon monoxide powder and a Mg powder with said oxide-coated soft magnetic powder.

22. The method according to claim 7 wherein said step of forming an oxide film on a surface of a soft magnetic powder comprises heating a soft magnetic powder in an oxidizing atmosphere at a temperature of room temperature to 500°

C.

23. The method according to claim 22, wherein said silicon monoxide is added in an amount of 0.01 to 1% by mass, and said Mg powder is added in an amount of 0.05 to 1% by mass.

24. The method according to claim 23, wherein said vacuum atmosphere is an atmosphere under a pressure of 1×

10<sup>−

12</sup> to 1×

10<sup>−

1</sup> MPa.

38. The method according to claim 7, wherein said heating in a vacuum or inert gas atmosphere is performed while tumbling.

39. The method according to claim 7, wherein said soft magnetic metal powder is an iron powder, an insulated-iron powder, Fe—

Al iron-based soft magnetic alloy powder, Fe—

Ni iron-based soft magnetic alloy powder, Fe—

Cr iron-based soft magnetic alloy powder, Fe—

Si iron-based soft magnetic alloy powder, Fe—

Si—

Al iron-based soft magnetic alloy powder, Fe—

Co iron-based soft magnetic alloy powder, Fe—

Co—

V iron-based soft magnetic alloy powder, or Fe—

P iron-based soft magnetic alloy powder.

40. A method for producing a raw powder material defined in claim 7 comprising a soft magnetic powder which has been subjected to oxidation treatment, which comprises the steps of:

adding and mixing a Si powder with an Fe—

Si iron-based soft magnetic powder or Fe powder, followed by heating in a non-oxidizing atmosphere to obtain an Fe—

Si iron-based soft magnetic powder having a high-concentration Si diffusion layer which has a Si concentration higher than the Fe—

Si iron-based soft magnetic powder or Fe powder; and

subjecting said Fe—

Si iron-based soft magnetic powder having a high-concentration Si diff layer to oxidizing treatment, thereby obtaining a surface-oxidized, Fe—

Si iron-based soft magnetic raw powder material having an oxide layer formed on the high-concentration Si diffusion layer.

41. A method for producing a composite soft magnetic material having excellent resistivity and mechanical strength, comprising the steps of:

subjecting a soft magnetic metal powder coated with a Mg-containing oxide film produced by the method of claim 7 to press molding; and

sintering the resultant at a temperature of 400 to 1,300°

C.

42. A method for producing a composite soft magnetic material having excellent resistivity and mechanical strength, comprising the steps of:

mixing an organic insulating material, inorganic insulating material or a mixed material of an organic insulating material and an inorganic insulating material with a soft magnetic metal powder coated with a Mg-containing oxide film produced by the method of claim 7, followed by powder compaction; and

sintering the resultant at a temperature of 500 to 1,000°

C.

8. A method for producing a soft magnetic powder coated with a Mg—

Si-containing oxide film, comprising the steps of;

forming an oxide film on a surface of a soft magnetic powder to provide an oxide-coated soft magnetic powder;

adding and mixing a Mg powder with said oxide-coated soft magnetic powder;

performing heating in a vacuum atmosphere at a temperature of 400 to 800°

C. during or following said mixing of a Mg powder with said oxide-coated soft magnetic powder;

adding and mixing a silicon monoxide powder with the resultant; and

performing heating in a vacuum atmosphere at a temperature of 600 to 1,200°

C. during or following said mixing of a silicon monoxide powder with the resultant.

25. The method according to claim 8 wherein said step of forming an oxide film on a surface of a soft magnetic powder comprises heating a soft magnetic powder in an oxidizing atmosphere at a temperature of room temperature to 500°

C.

26. The method according to claim 25, wherein said silicon monoxide is added in an amount of 0.01 to 1% by mass, and said Mg powder is added in an amount of 0.05 to 1% by mass.

27. The method according to claim 26, wherein said vacuum atmosphere is an atmosphere under a pressure of 1×

10<sup>−

12</sup> to 1×

10<sup>−

1</sup> MPa.

43. The method according to claim 8, wherein said heating in a vacuum or inert gas atmosphere is performed while tumbling.

44. The method according to claim 8, wherein said soft magnetic metal powder is an iron powder, an insulated-iron powder, Fe—

Al iron-based soft magnetic alloy powder, Fe—

Ni iron-based soft magnetic alloy powder, Fe—

Cr iron-based soft magnetic alloy powder, Fe—

Si iron-based soft magnetic alloy powder, Fe—

Si—

Al iron-based soft magnetic alloy powder, Fe—

Co iron-based soft magnetic alloy powder, Fe—

Co—

V iron-based soft magnetic alloy powder, or Fe—

P iron-based soft magnetic alloy powder.

45. A method for producing a raw powder material defined in claim 8 comprising a soft magnetic powder which has been subjected to oxidation treatment, which comprises the steps of:

adding and mixing a Si powder with an Fe—

Si iron-based soft magnetic powder or Fe powder, followed by heating in a non-oxidizing atmosphere to obtain an Fe—

Si iron-based soft magnetic powder having a high-concentration Si diffusion layer which has a Si concentration higher than the Fe—

Si iron-based soft magnetic powder or Fe powder; and

subjecting said Fe—

Si iron-based soft magnetic powder having a high-concentration Si diff layer to oxidizing treatment, thereby obtaining a surface-oxidized, Fe—

Si iron-based soft magnetic raw powder material having an oxide layer formed on the high-concentration Si diffusion layer.

46. A method for producing a composite soft magnetic material having excellent resistivity and mechanical strength, comprising the steps of:

subjecting a soft magnetic metal powder coated with a Mg-containing oxide film produced by the method of claim 8 to press molding; and

sintering the resultant at a temperature of 400 to 1,300°

C.

47. A method for producing a composite soft magnetic material having excellent resistivity and mechanical strength, comprising the steps of:

mixing an organic insulating material, inorganic insulating material or a mixed material of an organic insulating material and an inorganic insulating material with a soft magnetic metal powder coated with a Mg-containing oxide film produced by the method of claim 8, followed by powder compaction; and

sintering the resultant at a temperature of 500 to 1,000°

C.

12. A raw powder material for producing a soft magnetic powder coated with a Mg—

Si-containing oxide film, comprising an oxide-coated soft magnetic powder obtained by forming an oxide film on a surface of a soft magnetic powder.