HTS Tape Stainless Steel Substrate Electrochemical Polishing
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Solution Overview
Problem
The high cost and limited availability of expensive substrates, such as nickel-based alloys and high-chromium stainless steels, hinder the production of high-temperature superconductor strip conductors with high current densities, as they require expensive special alloys and are difficult to obtain in suitable forms.
Innovation Solution
A high-temperature superconductor strip conductor using a standard austenitic stainless steel substrate with a chromium content of less than 18% by mass, combined with electrochemical polishing to achieve a high surface quality, allowing for the deposition of biaxially oriented oxide-ceramic layers and enabling high current densities without the need for expensive alloys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If expensive substrates such as nickel-based alloys and high-chromium stainless steels are used, then high current densities and good surface properties are achieved, but substrate procurement costs increase significantly and availability is limited
Solution Approach 1:
The patent replaces expensive, specialized substrates (nickel-based alloys, high-chromium stainless steels) with a cheaper, readily available alternative (standard austenitic stainless steel with <18% Cr). The cost reduction is achieved by using common industrial materials that can be easily procured in large quantities, while the electrochemical polishing process ensures the surface quality needed for high current density applications
Solution Approach 2:
The patent changes the chromium content parameter from the conventional >18% (in high-grade stainless steels) to <18% (in standard austenitic stainless steel). This parameter change reduces material cost and improves availability while maintaining compatibility with HTS coatings through electrochemical polishing, which creates the necessary surface quality for high current density
2Quantity of substance
If standard austenitic stainless steel with chromium content <18% is used, then substrate costs are reduced and availability is improved, but surface quality may be insufficient for high current density applications
Solution Approach 1:
The patent applies electrochemical polishing as a preliminary surface treatment step before depositing the HTS coating. This preliminary action removes surface irregularities, creates a smooth morphology, and establishes the necessary surface quality on the standard stainless steel substrate to support high current density applications, thereby enabling the use of cheaper materials
3Manufacturing precision
If electrochemical polishing is applied to standard stainless steel, then surface quality is improved for HTS deposition, but additional processing steps are required
Solution Approach 1:
The electrochemical polishing process is a self-service treatment where the substrate itself serves as the electrode. The material removal occurs through controlled electrochemical dissolution, automatically adapting to the surface topography and creating a uniformly smooth surface without requiring external abrasives or complex mechanical polishing equipment
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
This approach significantly reduces substrate procurement costs while enabling high current densities, making it possible to produce cost-efficient high-temperature superconductor strip conductors suitable for long-distance electricity transport with minimal losses.
Implementation Method 1
an angular deviation distribution of less than 10° and an angular change distribution of less than 13.5°/μm, in particular an angular deviation distribution of less than 7° and an angular change distribution of less than 8°/μm, especially an angular deviation distribution of less than 4° and an angular change distribution of less than 5°/μm
Implementation Method 2
HTS layers are separated using common physical (PVD) or chemical (CVD or MOD) processes
Implementation Method 3
HTS layers are separated using common physical (PVD) or chemical (CVD or MOD) processes
Implementation Method 4
The disappearance of the electrical resistance below the transition temperature Tc enables lower line losses and an increase in the efficiency of a wide variety of devices
Data Source
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AI summary
A high-temperature superconducting ribbon conductor is proposed, comprising a substrate made of stainless steel with a chromium content of less than 18% by mass, preferably of type 1.4404 according to EN10027.