HTS Strip Copper-Graphene Stabilizing Layer for Strength Retention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Second-generation high-temperature superconducting (HTS) strips face significant degradation in mechanical and electrical properties due to the poor mechanical properties of silver and copper stabilizing layers, particularly when thickened, which affects engineering current density and tensile strength, especially in applications requiring high spatial locality like superconducting magnets.
Innovation Solution
A copper-graphene composite film stabilizing layer with a graphene mass fraction between 0.1% and 1% is deposited on the HTS strip using a copper-graphene double-target co-sputtering vapor deposition method, providing enhanced mechanical and electrical properties by improving tensile strength and maintaining high conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the thickness of silver and copper stabilizing layers is increased to improve mechanical properties, then tensile strength is improved, but engineering current density decreases significantly
Solution Approach 1:
The patent applies composite materials by combining copper with graphene to create a copper-graphene stabilizing layer. The graphene reinforcement (0.1-5 wt%) significantly enhances the mechanical strength of the stabilizing layer, allowing thinner layers to achieve the same tensile strength as much thicker conventional copper layers, thereby preserving engineering current density while improving mechanical properties
Solution Approach 2:
The patent changes the compositional parameters of the stabilizing layer by incorporating graphene at specific concentrations (0.1-5 wt%). This parameter change transforms the material properties, enabling the stabilizing layer to achieve high tensile strength at reduced thickness, thus resolving the contradiction between mechanical strength and electrical conductivity
2Reliability
If conventional copper plating is used to provide stabilizing layer, then electrical conductivity is maintained, but mechanical properties are significantly inferior to metal base strip
Solution Approach 1:
The patent creates a composite stabilizing layer by integrating graphene into the copper matrix. The graphene provides exceptional mechanical strength while the copper matrix maintains electrical conductivity. This composite structure simultaneously achieves both high electrical conductivity and superior mechanical properties, resolving the contradiction between these two requirements
3Strength
If high-strength metal lamination tapes are used to strengthen the strip, then mechanical properties are improved, but engineering current density decreases
Solution Approach 1:
The patent changes the thickness parameter of the stabilizing layer by using graphene-reinforced copper, which provides high mechanical strength at reduced thickness. This allows the stabilizing layer to be thinner while maintaining adequate mechanical properties, thereby preserving more superconducting material and maintaining high engineering current density
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 copper-graphene stabilizing layer increases tensile strength by 30%-70% and reduces conductivity attenuation to less than 10% IACS, compared to conventional copper plating processes, thereby enhancing the robustness and application areas of HTS strips.
Implementation Method 1
a copper-graphene double-target co-sputtering vapor deposition method
Data Source
AI summary
A second-generation high temperature superconducting (HTS) strip and a preparation method thereof are provided. The second-generation HTS strip includes a superconducting strip body and a stabilizing layer arranged thereon. The stabilizing layer is a copper-graphene composite film with a total thickness of 2-30 microns on one side. The superconducting strip may be obtained by the preparation method of: (1) putting a superconducting strip body into a magnetron sputtering reaction chamber, followed by pumping to a high-level vacuum and filling with a working gas; (2) using copper and graphene as targets, and performing a sputter coating by controlling a magnetron sputtering power, to deposit the targets onto at least one surface of the superconducting strip body. The prepared HTS strips containing copper-graphene stabilizing layer with high strength and high conductivity may have 30%-70% higher tensile strength than conventional copper plated superconducting strips, with less than 10% IACS attenuation in conductivity.