Iron-Based Soft Magnetic Powder With Cu Clusters for Low Iron Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The magnetic properties of existing Fe-based nanocrystalline alloy powders and dust cores are insufficient, and there is a need for improved magnetic flux density and reduced iron loss.
Innovation Solution
An iron-based soft magnetic powder with specific characteristics, including low crystallinity, high volume-based median circularity, optimized Cu cluster density and concentration, and a defined chemical composition, is developed, which is then coated with an insulating layer to enhance magnetic properties and reduce iron loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nanocrystalline materials are used to achieve high magnetic flux density and low coercive force, then magnetic flux density is improved and coercive force is reduced, but manufacturing precision and control of microstructure are significantly more difficult
Solution Approach 1:
The invention changes the chemical composition parameters by adding Cu element (0.01-5 mass%) to the Fe-Si-B alloy system, which modifies the phase transformation behavior and enables formation of nanocrystalline structure with specific properties. This compositional parameter change facilitates achieving high magnetic flux density while controlling coercive force through the Cu-induced microstructural modifications during solidification and heat treatment
Solution Approach 2:
The invention creates a composite microstructure consisting of nanocrystalline Fe-Si-B phases dispersed in an amorphous matrix, with Cu elements segregating to form clusters or precipitates. This composite structure combines the advantages of both amorphous and crystalline phases, achieving high magnetic flux density from the crystalline regions while maintaining low coercive force through the amorphous matrix and Cu cluster modifications
2Ease of manufacture
If particle circularity is increased to improve flowability during press mold filling, then ease of manufacture is improved, but magnetic properties may deteriorate due to changes in particle packing and density
Solution Approach 1:
The invention applies local quality by creating Cu-rich clusters at specific locations within the particle structure (preferentially at grain boundaries or within the amorphous matrix) rather than uniform distribution. This localized Cu segregation improves particle sphericity and flowability while maintaining the nanocrystalline microstructure and magnetic properties in the bulk material, as the Cu clusters are strategically positioned to enhance manufacturability without compromising the magnetic-active phases
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 resulting powder and dust core exhibit improved saturation magnetic flux density and reduced coercive force, leading to low iron loss and stable magnetic performance.
Implementation Method 1
each particle is covered with an insulating coating material
Implementation Method 2
The average diameter of crystallites in the nanocrystalline phase is less than 50 nm in order to inhibit an increase in coercive force caused by the crystalline phase
Implementation Method 3
In microstructure, the amorphous phase is responsible for low coercive force, while the nanocrystalline phase is responsible for high magnetic flux density
Implementation Method 4
Heat treatment of the soft magnetic powder under defined heat treatment conditions precipitates nanocrystals of Fe
Implementation Method 5
Heat treatment of the soft magnetic powder under defined heat treatment conditions precipitates nanocrystals of Fe
Implementation Method 6
dust cores are produced by loading insulation-coated soft magnetic particles (iron powder) into a press mold and press forming
Data Source
AI summary
Provided is an iron-based soft magnetic powder that may be used in producing a dust core having a low iron loss. The iron-based soft magnetic powder has a crystallinity of 10% or less, volume-based median circularity (C50) of 0.85 or more, and when heated to 400° C. at a heating rate of 3° C./min and held at 400° C. for 20 min in a nitrogen atmosphere, then allowed to naturally cool to room temperature, number density of Cu clusters in the powder of 1.00×103/μm3 or more and 1.00×106/m3 or less, and average Cu concentration of the Cu clusters of 30.0 at % or more.