Magnetic Core Oxide Layer Permeability Insulation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Magnetic cores for coil components require high initial permeability, but achieving this often results in mold breakage during high-pressure consolidation and compromised insulation properties due to increased heat treatment temperatures.

Innovation Solution

A magnetic core formed by heat-treated Fe-based alloy particles with an oxide layer containing Fe oxide and Fe3Al, where the peak intensity ratios of X-ray diffraction peaks are controlled to enhance initial permeability, and the oxide layer acts as an insulating layer between particles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high-pressure consolidation is used to increase green compact density, then initial permeability is improved, but mold breakage occurs and shape freedom is restricted

Engineering Contradiction:
Improveinitial permeabilityVSAvoidmold strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The invention changes the chemical composition parameters of the magnetic alloy powder by adding Al (1-10 mass%) and Cr (1-10 mass%) elements, which enables the formation of a protective oxide layer during heat treatment. This oxide layer provides bonding between particles and maintains insulation properties, allowing achievement of high initial permeability without requiring excessive consolidation pressure that would break the mold

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If heat treatment temperature is increased to increase space factor, then initial permeability is improved, but insulation properties are compromised due to sintering

Engineering Contradiction:
Improveinitial permeabilityVSAvoidinsulation properties
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The invention introduces an oxide layer as an intermediary substance formed on the particle surfaces during heat treatment. This oxide layer acts as a mediator that provides bonding between magnetic alloy particles while simultaneously maintaining electrical insulation properties, thus resolving the contradiction between achieving high initial permeability (requiring particle bonding) and maintaining insulation properties (requiring particle separation)

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a composite structure consisting of magnetic alloy particles with surface oxide layers. The composite material comprises the metallic magnetic alloy core providing magnetic properties and the oxide layer providing both bonding and insulation functions, enabling simultaneous achievement of high initial permeability and maintained insulation properties

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The magnetic core achieves high initial permeability while maintaining insulation properties and preventing mold breakage, with the oxide layer effectively bonding particles and reducing core loss.

Implementation Method 1

heat-treated in an oxygen-containing atmosphere to form an oxide layer obtained by the oxidation of the alloy particles on the surface of the particles

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

insulation properties are imparted to a magnetic core

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Implementation Method 3

The soft magnetic alloy particles are bonded via the oxide layer

Methodology Applied
Scientific EffectOxidation bonding: Oxidation

Implementation Method 4

A magnetic core obtained by consolidating a green compact of the magnetic alloy powder has a high saturation magnetic flux density

Methodology Applied
Scientific EffectSintering: Sintering

Data Source

PatentEP3514809B1Magnetic core and coil component
Publication Date: 2022.08.10 PROTERIAL LTD
  • EP3514809B1 patent drawingFigure 1A~1B
  • EP3514809B1 patent drawingFigure 2A~2B
  • EP3514809B1 patent drawingFigure 2C~3

AI summary

Provided are a magnetic core having a high initial permeability and a coil component including the same. The magnetic core has an X-ray diffraction spectrum of the magnetic core measured using Cu-Kα characteristic X-rays, wherein a peak intensity ratio (P1/P2) of a peak intensity P1 of a diffraction peak of an Fe oxide having a corundum structure appearing in a vicinity of 2θ = 33.2° to a peak intensity P2 of a diffraction peak of the Fe-based alloy having a bcc structure appearing in a vicinity of 2θ = 44.7° is 0.015 or less; and in the X-ray diffraction spectrum, a peak intensity ratio (P3/P2) of a peak intensity P3 of a superlattice peak of an Fe3Al ordered structure appearing in a vicinity of 2θ = 26.6° to the peak intensity P2 is 0.015 or more and 0.050 or less.