Soft Magnetic Ribbon Thickness Roughness Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing soft-magnetic metal strips for electromechanical components, particularly AC residual-current switches, face challenges in achieving reliable permeability and reproducibility, especially at 50 Hz frequencies, due to mechanical stresses and limitations in magnetization properties.
Innovation Solution
A soft-magnetic metal strip with a nanocrystalline or amorphous structure and a specific thickness-to-roughness ratio (d/Ra ≤ 5 to ≤ 25) is developed, featuring a fish scale pattern transverse and oblique to the longitudinal direction, which improves permeability and reduces eddy current losses, allowing for faster-acting electromechanical devices like residual current switches and speed sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the strip thickness is reduced to improve permeability and reduce eddy current losses, then the mechanical strength and reliability deteriorate
Solution Approach 1:
The patent uses nanocrystalline composite material with specific composition (Fe, Si, B, Nb, Cu) that combines soft magnetic properties with mechanical strength. The nanocrystalline structure provides both low eddy current losses and adequate mechanical properties, resolving the contradiction between thinning the strip and maintaining strength.
Solution Approach 2:
The patent optimizes multiple parameters simultaneously: strip thickness (10-20 μm), surface roughness (Ra ≈ 1 μm), alloy composition, and heat treatment temperature (500-600°C). By changing these parameters in combination, the patent achieves both reduced eddy current losses and maintained mechanical strength.
2Loss of time
If the strip thickness is reduced to improve response time, then the mechanical stress resistance deteriorates
Solution Approach 1:
The nanocrystalline composite material provides both fast magnetic response and mechanical durability. The specific alloy composition and nanocrystalline structure enable the thin strip to respond quickly to magnetic fields while maintaining resistance to mechanical stresses during handling and operation.
Solution Approach 2:
The patent creates different surface qualities at different locations: the top surface is smooth for magnetic performance, while the bottom surface has controlled roughness (Ra ≈ 1 μm) for mechanical strength. This local differentiation allows the thin strip to achieve both fast response and stress resistance.
3Loss of energy
If the surface roughness is increased to improve permeability, then the manufacturing precision deteriorates
Solution Approach 1:
The patent optimizes the surface roughness parameter to a specific value (Ra ≈ 1 μm) that balances permeability improvement with manufacturing feasibility. This precise parameter control allows achieving better magnetic performance while maintaining reproducible manufacturing quality.
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 enhances permeability and magnetic induction values, enabling efficient operation of electromechanical components with low coercive field strength, suitable for AC applications at 50 Hz, and improves the performance of AC-sensitive components such as residual current switches and distribution transformers.
Implementation Method 1
The soft magnetic metal strip has a nanocrystalline or amorphous structure and ratios of strip thicknesses to roughnesses d/Ra of 5≤d/Ra≤25
Implementation Method 2
The soft magnetic metal strip has a nanocrystalline or amorphous structure and ratios of strip thicknesses to roughnesses d/Ra of 5≤d/Ra≤25
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
The application relates to a soft-magnetic metal strip for electromechanical components, wherein the soft-magnetic metal strip has a nanocrystalline or amorphous structure. The metal strip has ratios of strip thickness to roughness of d/Ra of 5 = d/Ra = 25.