Soft Magnetic Flaky Powder and Method for Producing the Same

Patent metadata

Field	Value
Publication number	US-2017323711-A1
Application number	US-201515525422-A
Country	US
Kind code	A1
Filing date	Nov 9, 2015
Priority date	Nov 10, 2014
Publication date	Nov 9, 2017
Grant date	—

Abstract

In order to provide a soft magnetic flaky powder that is used primarily in a member for an RFID and that has the high real part μ′ of a magnetic permeability and the low imaginary part μ″ of the magnetic permeability even when having an average particle diameter of 30 μm or more, and a method for producing the soft magnetic flaky powder, the present invention provides a soft magnetic flaky powder obtained by flattening-treatment of a soft magnetic powder, in which an average particle diameter is more than 30 μm, a coercive force measured by applying a magnetic field in the longitudinal direction of the flaky powder is in a range of 240 to 640 A/m, a saturation magnetization is 1.0 T or more, and an aspect ratio is 30 or more, and a method for producing the soft magnetic flaky powder.

First claim

1 . A soft magnetic flaky powder obtained by flattening-treatment of a soft magnetic powder, wherein an average particle diameter D 50 is more than 30 μm, a coercive force Hc measured by applying a magnetic field in the longitudinal direction of the flaky powder is in a range of 240 to 640 A/m, a saturation magnetization is 1.0 T or more, and an aspect ratio is 30 or more.

2 . The soft magnetic flaky powder according to claim 1 , wherein the soft magnetic flaky powder comprises an Fe—Si—Cr alloy comprising Si: 15 mass % or less (excluding zero), Cr: from more than 6 mass % to 18 mass %, and the balance of Fe with unavoidable impurities.

3 . The soft magnetic flaky powder according to claim 1 , wherein the soft magnetic flaky powder comprises an Fe—Si—Cr alloy comprising Si: from more than 10 mass % to 15 mass %, Cr: 6 mass % or less (excluding zero), and the balance of Fe with unavoidable impurities.

4 . The soft magnetic flaky powder according to claim 1 , wherein the soft magnetic flaky powder has a real magnetic permeability μ′ of 45 or more and an imaginary magnetic permeability μ″ of 1 or less, which are magnetic properties in an RFID use or a 13.56 MHz band.

5 . A method for producing a soft magnetic flaky powder, comprising implementing a raw powder production step and a flattening-processing step of flattening the raw powder, thereby obtaining the soft magnetic flaky powder according to claim 1 .

6 . A method for producing a soft magnetic flaky powder, comprising implementing a raw powder production step using a gas atomization method or a disk atomization method, a flattening-processing step of flattening the raw powder, and a heat-treating step of heating the flattening-processed powder in a vacuum or argon atmosphere at 500° C. to 900° C., thereby obtaining the soft magnetic flaky powder according to claim 1 .

7 . The method for producing a soft magnetic flaky powder according to claim 5 , wherein the soft magnetic flaky powder has a real magnetic permeability μ′ of 45 or more and an imaginary magnetic permeability μ″ of 1 or less, which are magnetic properties in an RFID use or a 13.56 MHz band.

8 . The soft magnetic flaky powder according to claim 2 , wherein the soft magnetic flaky powder has a real magnetic permeability μ′ of 45 or more and an imaginary magnetic permeability μ″ of 1 or less, which are magnetic properties in an RFID use or a 13.56 MHz band.

9 . The soft magnetic flaky powder according to claim 3 , wherein the soft magnetic flaky powder has a real magnetic permeability μ′ of 45 or more and an imaginary magnetic permeability μ″ of 1 or less, which are magnetic properties in an RFID use or a 13.56 MHz band.

10 . The method for producing a soft magnetic flaky powder according to claim 6 , wherein the soft magnetic flaky powder has a real magnetic permeability μ′ of 45 or more and an imaginary magnetic permeability μ″ of 1 or less, which are magnetic properties in an RFID use or a 13.56 MHz band.

Assignees

• Sanyo Special Steel Co Ltd

Inventors

• MAEZAWA Fumihiro
• Sawada Toshiyuki

Classifications

• B22F1/068

  Flake-like particles · CPC title

• B22F9/04 Primary

  starting from solid material, e.g. by crushing, grinding or milling ({C22C1/1084 takes precedence}; crushing, grinding or milling, in general, see the relevant subclasses, e.g. B02C) · CPC title

• C22C38/18

  containing chromium · CPC title

• B22F1/0055

  Operations & Transport · mapped topic

• C22C2202/02

  Magnetic · CPC title