Magnetic core, method for producing magnetic core, and coil component

• US 10,453,599 B2
• Filed: 07/16/2015
• Issued: 10/22/2019
• Est. Priority Date: 07/16/2014
• Status: Active Grant

• Current Assignee: Hitachi Metals (Thailand) Ltd.
• Original Assignee: Hitachi Metals (Thailand) Ltd.
• Inventors: Noguchi, Shin, Nishimura, Kazunori, Mihara, Toshio
• Primary Examiner(s): Nguyen, Tuyen T
• Application Number:
  US15/326,071
• Publication Number:
  US 20170207017A1
• Time in Patent Office: 1,559 Days
• Field of Search: 336 65, 336 83, 336200, 336212, 336233-234
• CPC Class Codes: H01F 1/14791 Fe-Si-Al based alloys, e.g. Sendust
• CPC Class Codes: H01F 1/20 in the form of particles, e.g. powder H01F1/147 takes precedence
• CPC Class Codes: H01F 1/24 the particles being insulated
• CPC Class Codes: H01F 17/045 with core of cylindric geometry and coil wound along its longitudinal axis, i.e. rod or drum core
• CPC Class Codes: H01F 27/255 made from particles H01F27/26 takes precedence
• CPC Class Codes: H01F 27/2823 Wires H01F27/2866 takes precedence
• CPC Class Codes: H01F 27/292 Surface mounted devices
• 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

There is provided a magnetic core having high manufacturability and high magnetic permeability, to provide a method for manufacturing such a magnetic core, and to provide a coil component having such a magnetic core. The invention is directed to a magnetic core including: Fe-based soft magnetic alloy particles; and an oxide phase existing between the Fe-based soft magnetic alloy particles, wherein the Fe-based soft magnetic alloy particles include Fe—Al—Cr alloy particles and Fe—Si—Al alloy particles.

Claims

1. A magnetic core comprising:

Fe-based soft magnetic alloy particles; and

an oxide phase existing between the Fe-based soft magnetic alloy particles, wherein

the Fe-based soft magnetic alloy particles comprise Fe—

Al—

Cr alloy particles and Fe—

Si—

Al alloy particles;

the Fe—

Al—

Cr alloy particles and the Fe—

Si—

Al alloy particles are bonded with the oxide phase; and

the content of the Fe—

Al—

Cr alloy particles is 20% by weight or more based on the total weight of the Fe—

Al—

Cr alloy particles and the Fe—

Si—

Al alloy particles.

2. The magnetic core according to claim 1, wherein the oxide phase is richer in Al than the Fe-based soft magnetic alloy particles.

3. The magnetic core according to claim 1, which has a density of 5.4×

10³ kg/m³ or more.

4. The magnetic core according to claim 1, wherein the Fe-based soft magnetic alloy particles have an average particle size of 20 μ

m or less.

5. A method for manufacturing the magnetic core according to claim 1, the method comprising the steps of:

pressing a mixed powder comprising an Fe—

Al—

Cr alloy powder and an Fe—

Si—

Al alloy powder to form a compact;

heat-treating the compact to form the oxide phase; and

bonding the Fe—

Al—

Cr alloy particles and the Fe—

Si—

Al alloy particles with the oxide phase.

6. A coil component comprising:

the magnetic core according to claim 1; and

a coil provided on the magnetic core.

7. The magnetic core according to claim 1, wherein the oxide phase includes an oxide of the Fe-based soft magnetic alloy particles.

8. The magnetic core according to claim 1, wherein the magnetic core comprises a cylindrical coil holding part and either (i) a flange only at one end of the coil holding part or (ii) flanges at both ends of the coil holding part.

9. The magnetic core according to claim 8, wherein the magnetic core comprises a cylindrical coil holding part and a flange only at one end of the coil holding part.

10. The magnetic core according to claim 8, wherein the magnetic core comprises a cylindrical coil holding part and flanges at both ends of the coil holding part.