Amorphous Alloy Ribbon Composition for High Saturation Induction
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Solution Overview
Problem
Ferromagnetic amorphous alloy ribbons used in transformer cores and other devices face challenges with low saturation induction, high magnetic loss, reduced thermal stability, and surface defects, which hinder continuous casting and device efficiency.
Innovation Solution
A ferromagnetic amorphous alloy ribbon with a specific composition (Fe a Si b B c C d) is cast with controlled molten alloy surface tension and trace elements like Cu, Mn, and Cr, achieving high saturation induction, low magnetic loss, and reduced surface defects, ensuring continuous casting and improved thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the iron content is increased to achieve higher saturation induction, then the saturation induction improves, but the thermal stability degrades
Solution Approach 1:
The patent applies parameter changes by precisely controlling the chemical composition parameters of the alloy system. Specifically, it defines narrow ranges for Fe (80.5-83 at%), Si (0.5-6 at%), B (12-16.5 at%), and C (0.01-1 at%), along with specific ratios between elements (Si:C ratio and relationship between B content and Fe content). This compositional parameter optimization enables achieving saturation induction exceeding 1.60 T while maintaining thermal stability of up to 150 years at 150°C, resolving the contradiction between high iron content for saturation induction and thermal stability.
2Strength
If elements such as Sn, S, C and P are added to improve formability and saturation induction, then the saturation induction and formability improve, but the ductility of the cast ribbon deteriorates
Solution Approach 1:
The patent resolves this contradiction through precise parameter control, specifically limiting the carbon content to a narrow range of 0.01-1 at% and establishing a specific Si:C ratio relationship (b ≥ 166.5 × (100 - d) / 100 - 2a). This controlled addition of carbon and silicon, rather than using traditional ductility-enhancing elements like Sn, S, or P, achieves both high saturation induction (>1.60 T) and sufficient ductility for continuous casting of wide ribbons.
Solution Approach 2:
The patent creates a composite alloy system Fe-Si-B-C with specifically controlled compositions. The multi-element composition Fe a Si b B c C d with precise ratios creates a synergistic effect where carbon and silicon work together to enhance saturation induction while maintaining formability and ductility, avoiding the need for traditional alloying elements that compromise ductility.
3Strength
If the addition of P is made to increase saturation induction with increased Fe content, then the saturation induction improves, but the long-term thermal stability is lost
Solution Approach 1:
The patent explicitly excludes phosphorus from the alloy composition and instead uses a specific Fe-Si-B-C parameter combination to achieve high saturation induction. The defined composition ranges (Fe: 80.5-83 at%, Si: 0.5-6 at%, B: 12-16.5 at%, C: 0.01-1 at%) and element ratio relationships provide a stable amorphous structure that maintains both high saturation induction (>1.60 T) and long-term thermal stability of up to 150 years at 150°C, avoiding the thermal instability caused by phosphorus addition.
4Strength
If high Fe content is used to achieve high saturation induction, then the saturation induction improves, but the magnetic core loss increases due to reduced thermal stability
Solution Approach 1:
The patent resolves this contradiction through optimized compositional parameters that simultaneously achieve high saturation induction and low magnetic core loss. The specific Fe-Si-B-C composition with Fe (80.5-83 at%), Si (0.5-6 at%), B (12-16.5 at%), and C (0.01-1 at%) creates an amorphous structure with saturation induction exceeding 1.60 T and magnetic core loss below 0.14 W/kg at 60 Hz and 1.3 T induction. The controlled element ratios prevent thermal degradation that would otherwise increase core loss over time.
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 solution results in a ribbon with a saturation induction exceeding 1.60 T, low magnetic core loss, and reduced surface defects, enabling continuous casting and enhanced performance in energy-efficient devices like transformers and magnetic sensors.
Implementation Method 1
cast from a molten state of the alloy, with a molten alloy surface tension of greater than and equal to 1.1 N/m
Data Source
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AI summary
A ferromagnetic amorphous alloy ribbon includes an alloy having a composition represented by FeaSibBcCd where 80.5 </= a </= 83 at.%, 0.5 </=b </= 6 at.%, 12 </= c </=16.5 at.%, 0.01 </= d </= 1 at. % with a + b + c + d = 100 and incidental impurities; the ribbon being cast from a molten state of the alloy. The ribbon is suitable for use in transformer cores, rotational machines, electrical chokes, magnetic sensors and pulse power devices.