Soft Magnetic Alloy Nanocrystal Control for High Bs and Low He

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

There is a demand for soft magnetic alloys with improved soft magnetic properties for miniaturization and weight reduction in electronic components, as existing alloys do not effectively balance saturation magnetic flux density (Bs) and coercivity (He) within optimal ranges.

Innovation Solution

A soft magnetic alloy with nanocrystals having an average Heywood diameter of 5.0 nm to 25.0 nm, an average circularity of 0.50 to 0.90, and a specific composition formula (Fe(1−(α+β))X1αX2β)(1−(a+b+c+d))MaBbPcSid, where X1 and X2 are selected from specific elements, and M is from a group including Nb, Hf, Zr, Ta, Mo, and V, with controlled stress and heat treatment to achieve optimal nanocrystal shape and composition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If nanocrystal size is reduced to improve coercivity, then soft magnetic properties improve, but saturation magnetic flux density decreases

Engineering Contradiction:
Improvesoft magnetic propertiesVSAvoidsaturation magnetic flux density
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent optimizes the nanocrystal size parameter to a specific range (5.0 nm to 25.0 nm average Heywood diameter) and controls circularity (0.50 to 0.90) to achieve the best balance between coercivity and saturation magnetic flux density. This parameter optimization resolves the contradiction by finding the optimal size window where both properties are satisfied simultaneously.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If nanocrystal size is reduced to improve coercivity, then soft magnetic properties improve, but crystal growth control becomes more difficult

Engineering Contradiction:
ImprovecoercivityVSAvoidcrystal grain size control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent specifies precise nanocrystal size parameters (average Heywood diameter of 5.0 nm to 25.0 nm) and circularity (0.50 to 0.90) to control crystal growth. By defining these specific parameter ranges, the patent makes the manufacturing process more controllable and reproducible, resolving the contradiction between improving coercivity through size reduction and maintaining manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs preliminary heat treatment before final nanocrystallization to pre-arrange the atomic structure and prepare the material for controlled nanocrystal formation. This preliminary action ensures that subsequent heat treatment produces nanocrystals within the desired size range with consistent circularity, making the overall process more controllable.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If conventional soft magnetic alloys are used, then manufacturing is simple, but soft magnetic properties are insufficient for miniaturization

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidsoft magnetic properties
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent uses a composite structure consisting of nanocrystals dispersed in an amorphous matrix. This composite material approach combines the benefits of crystalline phases (high saturation magnetic flux density) with amorphous phases (low coercivity), achieving excellent soft magnetic properties while maintaining compatibility with existing manufacturing processes like melt spinning and heat treatment.

Inventive Principle:
Principle #40Composite materials

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 Bs and low He, enhancing soft magnetic properties while preventing the growth of larger crystals, thereby improving the performance of magnetic cores and components in electronic devices.

Implementation Method 1

nanocrystals having an average Heywood diameter value of 5.0 nm or more and 25.0 nm or less, in which an average circularity of the nanocrystals is 0.50 or more and 0.90 or less

Methodology Applied
Scientific EffectMagnetic anisotropy: Anisotropy

Implementation Method 2

the soft magnetic alloy according to the present invention is a soft magnetic alloy having good soft magnetic properties

Methodology Applied
Scientific EffectMagnetic domain wall motion:

Data Source

PatentUS11827962B2Soft magnetic alloy, magnetic core, magnetic component, and electronic device
Publication Date: 2023.11.28 TDK CORP

AI summary

The present invention provides a soft magnetic alloy having good soft magnetic properties. The soft magnetic alloy includes nanocrystals having an average Heywood diameter value of 5.0 nm or more and 25.0 nm or less, in which an average circularity of the nanocrystals is 0.50 or more and 0.90 or less.