Metal magnetic particle, inductor, method for manufacturing metal magnetic particle, and method for manufacturing metal magnetic core

Patent metadata

Field	Value
Publication number	US-12308162-B2
Application number	US-202318345907-A
Country	US
Kind code	B2
Filing date	Jun 30, 2023
Priority date	Mar 27, 2020
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

A metal magnetic particle provided with an oxide layer on a surface of an alloy particle containing Fe and Si. The oxide layer has a first oxide layer, a second oxide layer, and a third oxide layer from a side of the alloy particle. All of the first oxide layer, the second oxide layer, and the third oxide layer contain Si. Also, in line analysis of element content by using a scanning transmission electron microscope-energy dispersive X-ray spectroscopy, the first oxide layer is a layer having Fe content smaller than Si content in the alloy particle, the second oxide layer is a layer having Fe content larger than the Si content in the alloy particle, and the third oxide layer is a layer having Fe content smaller than the Si content in the alloy particle.

First claim

What is claimed is:

1. A method for manufacturing a metal magnetic core, comprising:
mixing a raw material particle having, on a surface of an alloy particle containing Fe and Si, an Si oxide film and an Fe oxide film from a side of the alloy particle with Si alkoxide and alcohol;
forming a coating film forming particle formed with a coating film containing silicon oxide by hydrolyzing and drying the Si alkoxide;
molding the coating film forming particle; and
forming an oxide layer on the surface of the alloy particle by performing heat treatment on the coating film forming particle in an oxidizing atmosphere,
wherein
an average thickness of the coating film is from larger than 14 nm to 30 nm,
a temperature of the heat treatment is from 690° C. to lower than 750° C., and
the molding includes printing with and drying paste containing the coating film forming particles.

2. The method for manufacturing the metal magnetic core according to claim 1 , wherein
the Si alkoxide is tetraethoxysilane.

Assignees

• Murata Manufacturing Co

Inventors

• Ishida Takuya
• Yamamoto Makoto
• Uji Katsutoshi
• Ishida Yuya
• Odahara Mitsuru

Classifications

• H01F1/33 Primary

  mixtures of metallic and non-metallic particles; metallic particles having oxide skin · CPC title

• B22F1/145

  Chemical treatment, e.g. passivation or decarburisation · CPC title

• Y10T428/12181

  Composite powder [e.g., coated, etc.] · CPC title

• B22F1/142

  Thermal or thermo-mechanical treatment · CPC title

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title