Powder for magnetic core, method for manufacturing same, and dust core

Patent metadata

Field	Value
Publication number	US-2024186043-A1
Application number	US-202218282727-A
Country	US
Kind code	A1
Filing date	Feb 28, 2022
Priority date	Mar 19, 2021
Publication date	Jun 6, 2024
Grant date	—

Abstract

A method for manufacturing a powder for magnetic cores includes: a calcination step for heating a first powder composed of an iron alloy containing Si at 975° C. to 1175° C. to obtain a calcined body; a cracking step for disintegrating the calcined body to obtain a second powder; and a powder annealing step for annealing the second powder to obtain a third powder. The powder annealing step is performed, for example, by heating the second powder at 550° C. to 850° C. The third powder is composed, for example, of soft magnetic particles satisfying an average particle diameter of 50 to 250 μm, an average crystal particle diameter of 30 to 100 μm, and an average particle hardness of 100 to 190 Hv. Such a dust core is suitable, for example, when used in an alternating magnetic field having a frequency of 1 to 3 kHz.

First claim

1 . A method for manufacturing a powder for magnetic cores, comprising:
a calcination step for heating a first powder composed of an iron alloy containing Si at 975° C. to 1175° C. to obtain a calcined body; a cracking step for disintegrating the calcined body to obtain a second powder; and a powder annealing step for annealing the second powder to obtain a third powder.

2 . The method for manufacturing a powder for magnetic cores according to claim 1 , wherein the powder annealing step includes heating the second powder at 550° C. to 850° C.

3 . A powder for magnetic cores that is composed of an iron alloy containing Si,
the powder comprising soft magnetic particles satisfying an average particle diameter of 50 to 250 μm, an average crystal particle diameter of 30 to 100 μm, and an average particle hardness of 100 to 190 Hv.

4 . The powder for magnetic cores according to claim 3 , wherein the iron alloy contains 1 to 4 mass % of Si with respect to the iron alloy as a whole.

5 . The powder for magnetic cores according to claim 3 , wherein the soft magnetic particles are coated with insulation.

6 . A dust core obtained by molding the powder for magnetic cores according to claim 3 .

7 . The dust core according to claim 6 , used in an alternating magnetic field with a frequency of 1 to 3 kHz.

Assignees

• Aichi Steel Corp

Inventors

• Hamada Norihiko

Classifications

• C22C33/0271

  with only C, Mn, Si, P, S, As as alloying elements, e.g. carbon steel · CPC title

• B22F1/05

  Metallic powder characterised by the size or surface area of the particles · CPC title

• H01F1/24 Primary

  the particles being insulated · CPC title

• B22F1/102

  Metallic powder coated with organic material · CPC title

• B22F1/142

  Thermal or thermo-mechanical treatment · CPC title