Magnetic Material with Oxide Phase Distribution for Eddy Current Loss Reduction
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Solution Overview
Problem
Existing soft magnetic materials face challenges with eddy current loss and high costs due to the need for lamination and complex processing steps, while also lacking high saturation magnetization and oxidation resistance, making them unsuitable for high-performance, high-speed applications like next-generation automobiles.
Innovation Solution
A magnetic material with a nano-dispersed α-(Fe,Ni) phase and a Ni-enriched phase is developed, allowing for high saturation magnetization and reduced eddy current loss through a powder sintering process that eliminates the need for lamination and simplifies production, while maintaining high oxidation resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If metallic magnetic materials (silicon steel, sendust) are used to achieve high saturation magnetization, then magnetic performance is improved, but eddy current loss increases and lamination processing is required
Solution Approach 1:
The patent changes the fundamental parameter of material structure from continuous metallic phase to composite structure with oxide phase distribution. By controlling the average grain size to 1-10 μm and distributing oxide phases (FeAl3, FeSi2, FeB2) throughout the sendust matrix, the material achieves both high saturation magnetization (1.4-1.6 T) and reduced eddy current loss without requiring lamination.
Solution Approach 2:
The patent creates a composite magnetic material consisting of a sendust base phase (Fe-Al-Si) with dispersed oxide precipitates (FeAl3, FeSi2, FeB2). This composite structure combines the high magnetization of metallic sendust with the high resistivity of oxide phases, achieving saturation magnetization of 1.4-1.6 T while reducing eddy current loss through the insulating oxide distribution.
2Loss of energy
If silicon steel sheets are laminated to reduce eddy current loss, then eddy current loss is reduced, but manufacturing complexity and cost increase
Solution Approach 1:
The patent enables the material to self-regulate eddy current loss through internal oxide phase distribution rather than requiring external lamination processing. The oxide precipitates (FeAl3, FeSi2, FeB2) naturally form during controlled cooling and heat treatment, creating intrinsic eddy current barriers without manual stacking or insulation layer application.
Solution Approach 2:
The patent extracts the eddy current suppression function from the processing stage (lamination) and integrates it into the material structure itself. By incorporating oxide phases during solidification and heat treatment, the material inherently possesses eddy current resistance without requiring separate lamination operations.
3Force
If amorphous alloys are used to reduce coercive force, then soft magnetic properties are improved, but saturation magnetization decreases
Solution Approach 1:
The patent applies local quality by creating regions of different phases at different scales. The sendust matrix provides high saturation magnetization (1.4-1.6 T) while locally dispersed oxide precipitates (1-10 μm average grain size) provide domain wall pinning sites that reduce coercive force. This local phase distribution optimizes both magnetic properties simultaneously.
4Force
If nanocrystalline soft magnetic materials are used to achieve low coercive force, then soft magnetic properties are improved, but eddy current loss remains high due to thin ribbon form
Solution Approach 1:
The patent transitions from the thin ribbon geometry of nanocrystalline materials to a bulk solid structure with controlled grain size (1-10 μm). This dimensional change eliminates the need for lamination while maintaining low coercive force through fine grain distribution and reducing eddy current loss through oxide phase barriers at grain boundaries.
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 material achieves high saturation magnetization and low eddy current loss, enabling its use in thick, high-performance applications without the complexity and cost of lamination, and exhibits excellent oxidation resistance.
Implementation Method 1
a magnetic material comprising a phase (first phase) containing nickel in an α-Fe phase and a Ni-enriched phase (second phase)
Implementation Method 2
reduced eddy current loss through a powder sintering process
Data Source
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AI summary
Provided are a new, highly magnetically stable magnetic material which has higher saturation magnetization than ferrite-based magnetic materials, and with which problems of eddy current loss and the like can be solved due to higher electric resistivity than that of existing metal-based magnetic materials, and a method for manufacturing the same. A magnetic material powder is obtained by reducing in hydrogen Ni-ferrite nanoparticles obtained by wet synthesis and causing grain growth, while simultaneously causing nanodispersion of an α-(Fe, Ni) phase and an Ni-enriched phase by means of a phase dissociation phenomenon due to disproportional reaction. The powder is sintered to obtain a solid magnetic material.