Fe-Based Nanocrystal Alloy for Low Core Loss

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Solution Overview

Problem

Current magnetic alloys used in electronic and communication devices face challenges in achieving high saturation magnetic flux density, low coercive force, and high permeability, which are essential for reducing energy loss and improving efficiency, particularly in power circuits.

Innovation Solution

A soft magnetic alloy with a specific compositional formula (Fe(1−(α+β))X1αX2β)(1−(a+b+c+d+e)BaSibCcCudMe, where X1 and X2 are selected from specific elements, and M includes Nb, Hf, Zr, Ta, Ti, Mo, W, and V, allowing for the formation of a Fe-based nanocrystal structure through heat treatment, resulting in improved magnetic properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional Fe-based soft magnetic alloys are used, then saturation magnetic flux density can be maintained, but coercive force remains high and permeability is insufficient

Engineering Contradiction:
Improvecore lossVSAvoidmagnetic properties
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The invention changes the chemical composition parameters of the Fe-based alloy by adding specific amounts of B (0.1-1.0 wt%), Si (0.1-2.0 wt%), P (0.01-0.5 wt%), C (0.01-0.1 wt%), and Cu (0.01-0.5 wt%), while controlling Fe content at 70-85 wt%. These parameter changes enable the formation of an amorphous structure that achieves both low coercive force (≤5 A/m) and high saturation magnetic flux density (≥1.5 T), resolving the contradiction between energy loss reduction and magnetic property maintenance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite amorphous alloy system combining Fe with multiple elements (B, Si, P, C, Cu) in specific proportions. This composite material approach produces an amorphous phase with superior magnetic properties compared to conventional crystalline Fe-based alloys, achieving simultaneous improvement in coercive force, saturation magnetic flux density, and permeability, thereby reducing core loss while maintaining reliability.

Inventive Principle:
Principle #40Composite materials

2Reliability

If alloy composition is optimized for high saturation magnetic flux density, then energy loss decreases, but achieving low coercive force and high permeability simultaneously becomes difficult

Engineering Contradiction:
Improvesaturation magnetic flux densityVSAvoidalloy composition complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention establishes specific parameter ranges for each alloying element: B (0.1-1.0 wt%), Si (0.1-2.0 wt%), P (0.01-0.5 wt%), C (0.01-0.1 wt%), Cu (0.01-0.5 wt%), and Fe (70-85 wt%). Within these defined parameters, the alloy achieves optimal magnetic properties without requiring complex compositions. The structured parameter approach simplifies the composition design while achieving high saturation magnetic flux density (≥1.5 T), low coercive force (≤5 A/m), and high permeability (μ′≥20,000).

Inventive Principle:
Principle #35Parameter changes

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 alloy achieves high saturation magnetic flux density, low coercive force, and high permeability, leading to reduced core loss and energy consumption, making it suitable for compact and efficient magnetic components.

Implementation Method 1

By having the above characteristics, the soft magnetic alloy according to the present invention tends to attain a structure which tends to easily form a Fe-based nanocrystal alloy by carrying out a heat treatment.

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 2

the soft magnetic alloy according to the present invention tends to attain a structure which tends to easily form a Fe-based nanocrystal alloy by carrying out a heat treatment

Methodology Applied
Scientific EffectNanocrystal formation: Crystallisation

Data Source

PatentUS11508502B2Soft magnetic alloy and magnetic component
Publication Date: 2022.11.22 TDK CORP

AI summary

A soft magnetic alloy or the like combining high saturated magnetic flux density, low coercive force and high magnetic permeability μ′ having the composition formula (Fe(1−(α+β))X1αX2β)(1−(a+b+c+d+e))BaSibCcCudMe. X1 is one more elements selected from the group consisting of Co and Ni, X2 is one or more elements selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Bi, N, O and rare earth elements, and M is one or more elements selected from the group consisting of Nb, Hf, Zr, Ta, Ti, Mo, W and V. 0.140<a≤0.240, 0≤b≤0.030, 0<c<0.080, 0<d≤0.020, 0≤e≤0.030, α≥0, β≥0, and 0≤α+β≤0.50 are satisfied.