Fe2SiO4-Coated Alloy Particles for Low-Loss Powder Magnetic Cores

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Solution Overview

Problem

Dust cores made from existing alloy particles suffer from insufficiently reduced eddy-current loss and low strength.

Innovation Solution

Alloy particles with a core portion made of iron and silicon, coated with Fe2SiO4, where the peak intensity ratio of FeO to Fe2SiO4 in the coating is 0.2 or lower, are used to form a dust core.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a coating layer is formed by reacting silicon resin and ferrite plating, then the eddy-current loss is reduced, but the strength becomes low

Engineering Contradiction:

Improveeddy-current lossVSAvoidstrength

Core Design Contradiction:

Loss of energyVSStrength

Solution Approach 1:

The patent changes the chemical composition parameters of the coating layer by controlling the silicon content (0.1-5 mass%) and forming Fe2SiO4 spinel structure. This parameter optimization reduces eddy-current loss while maintaining sufficient strength, resolving the contradiction between energy loss reduction and mechanical strength.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite coating layer containing Fe2SiO4 spinel structure formed by the reaction between silicon-containing alloy and ferrite plating. This composite structure combines the advantages of both materials to achieve low eddy-current loss while maintaining adequate strength properties.

Inventive Principle:

Principle #40Composite materials

2Loss of energy

If the coating layer contains Fe2SiO4 with low FeO content, then the eddy-current loss is reduced, but the manufacturing precision becomes difficult to control

Engineering Contradiction:

Improveeddy-current lossVSAvoidpeak intensity ratio control

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

The patent establishes specific parameter ranges for FeO peak intensity ratio (IA/IB ≤ 0.2) and silicon content (0.1-5 mass%) to achieve the desired coating composition. By defining these quantitative parameters, the patent makes it possible to control the manufacturing process while achieving low eddy-current loss.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses XRD peak intensity ratio as a feedback parameter to control the coating quality. By measuring the ratio of FeO to Fe2SiO4 peak intensities, the manufacturing process can be monitored and adjusted to ensure the coating meets the required specifications for low eddy-current loss.

Inventive Principle:

Principle #23Feedback

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 solution results in alloy particles with low eddy-current loss and high strength, enabling improved relative permeability and enhanced sintering properties.

Implementation Method 1

the coating portion contains Fe 2 SiO 4 , and, when measurement is performed on the coating portion through X-ray diffraction, a strongest peak intensity of FeO is defined as IA, and a strongest peak intensity of the Fe 2 SiO 4 is defined as IB, a peak intensity ratio (IA/IB) has a value of 0.2 or lower

Methodology Applied

Scientific EffectElectrical insulation: Dielectric

Data Source

PatentEP4641593A1Alloy particles, powder magnetic core, electronic element, electronic appliance, electric motor, and dynamo

Publication Date: 2025.10.29 NITERRA CO LTD

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AI summary

An alloy particle (5) includes: a core portion (1) made of an alloy that contains iron and silicon; and a coating portion (3) coating the core portion (1). The coating portion (3) contains Fe2SiO4, and, when measurement is performed on the coating portion (3) through X-ray diffraction, a strongest peak intensity of FeO is defined as IA, and a strongest peak intensity of the Fe2SiO4 is defined as IB, a peak intensity ratio (IA/IB) has a value of 0.2 or lower.