Fe-based amorphous alloy core loss reduction

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Solution Overview

Problem

Despite advancements in reducing core loss in Fe-Si-B amorphous alloys, achieving a core loss below 0.10 W/kg at a flux density of 1.3 T and 50 Hz remains challenging, with existing compositions struggling to maintain consistency and stability.

Innovation Solution

An Fe-based amorphous alloy composition optimized with P, C, Si, Al, and B, along with partial replacement of Fe with Ni, Cr, or Co, to achieve improved soft magnetic properties and reduced core loss, specifically targeting a core loss of 0.10 W/kg or less through precise elemental content management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional Fe-Si-B amorphous alloy compositions are used, then core loss can be reduced to below 0.12 W/kg, but achieving core loss of 0.10 W/kg or less remains extremely difficult

Engineering Contradiction:
Improvecore lossVSAvoidconsistency of core loss reduction
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the compositional parameters of the amorphous alloy. Specifically, it limits Si content to 0.1-5 at.% and Al content to 0.1-3 at.% (total 0.1-5 at.%), while maintaining Fe at 78-86 at.% and P+C at 10-35 at.%. This precise parameter control enables achieving core loss of 0.10 W/kg or less at W13/50, resolving the contradiction between energy loss reduction and reliability of consistent performance.

Inventive Principle:
Principle #35Parameter changes

2Strength

If Fe content is increased to maintain saturation magnetic flux density, then magnetic properties are improved, but core loss reduction becomes more difficult

Engineering Contradiction:
Improvesaturation magnetic flux densityVSAvoidcore loss
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The patent applies local quality by creating a specific compositional distribution where Fe (78-86 at.%) provides high saturation magnetic flux density, while P (6-20 at.%) and C (2-10 at.%) locally reduce core loss. The synergistic combination of these elements with different local functions achieves both high magnetic strength and low energy loss, resolving the contradiction between these two properties.

Inventive Principle:
Principle #3Local quality

3Loss of energy

If P and C content is increased to reduce core loss, then energy loss decreases, but manufacturing precision and composition stability become challenging

Engineering Contradiction:
Improvecore lossVSAvoidcomposition control
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent applies composite materials by combining P and C elements in a specific ratio within the amorphous alloy matrix. The composite structure of Fe-P-C-Si-Al amorphous alloy allows P and C to work synergistically for core loss reduction while the amorphous matrix maintains composition stability. This resolves the contradiction between energy loss reduction and manufacturing precision by creating a stable composite material system.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentUS7918946B2Fe-based amorphous alloy excellent in soft magnetic properties
Publication Date: 2011.04.05 NIPPON STEEL CORPORATION

AI summary

The invention provides an amorphous alloy with good soft magnetic properties, namely an Fe-based amorphous alloy having excellent soft magnetic properties comprising, in at. %, Fe: 78 to 86%, P: 6 to 20%, C: 2 to 10%, one or both of Si and Al: 0.1 to 5%, and a balance of unavoidable impurities. P or C can as required be partially or totally replaced with B: 1 to 18%.