Metal Powder Core with Copper Dispersion for Low Core Loss
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Solution Overview
Problem
Existing metal powder cores in power supply circuits face challenges in reducing core loss, which affects efficiency and size reduction in applications like electrical household appliances, hybrid vehicles, and photovoltaic power generation, despite the use of Fe—Si—Al family magnetic materials and Fe-based amorphous alloy powders.
Innovation Solution
A metal powder core configuration is developed where Cu is dispersed among soft magnetic material powder, specifically pulverized powder of soft magnetic alloy ribbon, to achieve reduced core loss, with Cu content between 0.1% to 7% by total mass, and a silicon oxide film is applied for enhanced insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If Fe-based amorphous alloy powder or Fe—Si—Al family magnetic material is used in metal powder core, then saturation magnetic flux density is improved, but core loss is not sufficiently reduced
Solution Approach 1:
The patent combines pulverized soft magnetic alloy ribbon (Fe-based amorphous or nanocrystalline) with Cu powder to create a composite metal powder core. The Cu powder (0.1-10 mass%) disperses among the magnetic powder particles, creating a composite structure that reduces core loss while maintaining high saturation magnetic flux density. This composite approach allows simultaneous optimization of both magnetic properties and loss characteristics.
Solution Approach 2:
The patent changes the material composition parameters by introducing Cu powder at specific concentrations (0.1-10 mass%, preferably 0.1-5 mass%). It also controls the pulverized ribbon thickness (5-50 μm) and applies insulation treatments (oxide films, phosphate coatings) with controlled thickness. These parameter changes optimize the balance between saturation magnetic flux density and core loss reduction.
2Loss of energy
If insulation treatment is applied to magnetic powder surface, then eddy current loss is suppressed, but manufacturing complexity increases
Solution Approach 1:
The patent employs self-forming insulation mechanisms where oxide films (such as SiO2) naturally form on the surface of the pulverized soft magnetic alloy ribbon particles during the pulverization process or subsequent heating. This self-service approach provides insulation without requiring complex external coating equipment or multiple processing steps, thereby suppressing eddy current loss while maintaining manufacturing simplicity.
Solution Approach 2:
The patent controls the insulation layer thickness within specific ranges (oxide film: 1-100 nm) and selects appropriate insulation methods (oxide formation, phosphate coating, organic coating) based on the desired balance between eddy current suppression and manufacturing complexity. By optimizing these parameters, the patent achieves effective insulation with minimal process complexity.
3Loss of energy
If Cu powder is added to reduce core loss, then initial permeability may decrease, but core loss is reduced
Solution Approach 1:
The patent optimizes the Cu powder content within a specific range (0.1-10 mass%, preferably 0.1-5 mass%) to balance core loss reduction and initial permeability maintenance. It also controls the average particle size of Cu powder (1-10 μm) and the pulverized ribbon thickness (5-50 μm) to ensure proper dispersion and minimize negative effects on initial permeability while achieving significant core loss reduction.
Solution Approach 2:
The Cu powder is dispersed locally among the magnetic powder particles rather than uniformly distributed, creating regions with different properties. This local dispersion allows Cu to effectively reduce core loss at particle interfaces and boundaries while minimizing its overall impact on the bulk magnetic properties and initial permeability of the core material.
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
This configuration significantly reduces core loss, achieving hysteresis loss below 180 kW/m3 at 20 kHz and 150 mT, improving efficiency and enabling size reduction in coil components and devices, while maintaining initial permeability and reducing heat generation.
Implementation Method 1
the hysteresis loss Phv measured on measurement conditions of a frequency of 20 kHz and an applied magnetic flux density of 150 mT is 180 kW/m3 or lower
Implementation Method 2
a high saturation magnetic flux density and a low core loss are required
Implementation Method 3
electric resistance is improved by the insulation treatment so that eddy current loss is suppressed
Implementation Method 4
the soft magnetic material powder is pulverized powder of soft magnetic alloy ribbon
Data Source
AI summary
In a metal powder core constructed from soft magnetic material powder and a coil component employing this, a configuration suitable for reduction of a core loss is provided. The metal powder core constructed from soft magnetic material powder is characterized in that Cu is dispersed among the soft magnetic material powder. It is characterized in that, preferably, the soft magnetic material powder is pulverized powder of soft magnetic alloy ribbon and that Cu is dispersed among the pulverized powder of soft magnetic alloy ribbon. Further, it is characterized in that, preferably, the soft magnetic alloy ribbon is a Fe-based nano crystal alloy ribbon or a Fe-based alloy ribbon showing a Fe-based nano crystalline structure and that the pulverized powder has a nano crystalline structure.