Superconducting Wire Joining via Micro-Crystal Growth
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Solution Overview
Problem
The existing methods for joining superconducting wire materials using the MOD method often result in an inadequately formed superconducting layer, leading to low yield and resistance issues in the joining process.
Innovation Solution
A method involving the formation of micro-crystals on the joining surfaces of oxide superconducting films, followed by thermal treatment in an atmosphere with controlled oxygen concentration to decompose carbon compounds and promote crystal growth, ensuring a stable superconducting layer is formed between the joined surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the MOD method is used to join superconducting wire materials, then joining can be performed in a superconducting state with zero resistance, but the superconducting layer is not appropriately formed, decreasing the yield
Solution Approach 1:
The patent applies preliminary action by forming micro-crystals of oxide superconducting material on the joining surfaces before the actual joining process. This preliminary crystal formation ensures that when the superconducting layers are joined, the micro-crystals facilitate proper superconducting layer formation, thereby maintaining zero resistance while improving joining yield.
Solution Approach 2:
The patent utilizes parameter changes by controlling the oxygen concentration in the atmosphere during the heating process. By adjusting the oxygen concentration parameter, the micro-crystals are properly formed and grown, which ensures appropriate superconducting layer formation and resolves the yield issue while maintaining the superconducting state.
2Ease of manufacture
If thermal diffusion treatment is used to join superconducting wire materials, then joining can be achieved, but the oxide superconducting materials are easily decomposed at temperatures higher than their melting point
Solution Approach 1:
The patent applies parameter changes by using a lower heating temperature regime combined with controlled oxygen concentration atmosphere. This approach enables joining of superconducting wire materials without reaching decomposition temperatures, thereby maintaining material stability while achieving successful joining. The micro-crystal formation and controlled thermal processing allow joining at temperatures below the melting point of oxide superconductors.
Solution Approach 2:
The patent employs an inert or controlled oxygen concentration atmosphere during the heating and joining process. This controlled atmospheric environment prevents oxidation and decomposition of the oxide superconducting materials, allowing thermal processing to be performed safely at temperatures that would otherwise cause material degradation.
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 enhances the yield of the joining process by forming a superconducting layer with zero resistance, allowing for the efficient production of lengthened superconducting wire materials suitable for permanent current applications.
Implementation Method 1
a heat-joining step of heating the overlapped joining surfaces to grow the micro-crystal, thereby forming, as a joining layer, a superconducting layer of the oxide superconducting material
Implementation Method 2
thermal treatment in an atmosphere with controlled oxygen concentration to decompose carbon compounds
Implementation Method 3
oxide superconducting materials having superconductivity at a temperature of liquid nitrogen
Data Source
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AI summary
There is provided a technique for producing a superconducting wire material in which the yield in a process of joining superconducting wire materials is improved over the related art. A method for producing a superconducting wire material lengthened by joining end portions of superconducting wire materials each having an oxide superconducting film, the end portions serving as joining surfaces, includes a step of disposing a micro-crystal of an oxide superconducting material on each of the joining surfaces of the oxide superconducting films, a pasting step of overlapping and pasting together the joining surfaces on which the micro-crystal is disposed, and a heat-joining step of heating the overlapped joining surfaces to grow the micro-crystal, thereby forming, as a joining layer, a superconducting layer of the oxide superconducting material to join the joining surfaces to each other. A superconducting joining member for lengthening a superconducting wire material by performing heating while the superconducting joining member is pasted so as to bridge oxide superconducting thin films of two superconducting wire materials to join the two superconducting wire materials, wherein a micro-crystal of an oxide superconducting material is disposed on a joining surface.