Copper-Sheathed Superconductor Assembly With Thin Nb Diffusion Barrier

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Solution Overview

Problem

Existing superconductor manufacturing methods, such as the RIT and tubular methods, are costly due to high material and process requirements, and suffer from limited current carrying capacity and contamination issues.

Innovation Solution

A metal assembly precursor is formed within a hollow copper support element, incorporating conductor elements, a core, and interstitial elements to enhance superconducting properties, with a diffusion blocking layer to prevent contamination, and a method involving cold drawing and reaction heat treatment to produce a superconductor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If RIT method is used with thick niobium barrier to separate filament bundle from copper sheath, then contamination of copper jacket is prevented, but manufacturing cost increases significantly

Engineering Contradiction:
Improvecopper jacket contaminationVSAvoidmanufacturing cost
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

A thin niobium barrier layer (5-20 micrometers) is introduced as an intermediary between the filament bundle and copper sheath. This thin barrier suffices to prevent Sn diffusion to the copper jacket while significantly reducing the amount of expensive niobium material compared to traditional thick barriers, thereby resolving the contradiction between contamination prevention and manufacturing cost.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the thickness parameter of the niobium barrier from traditional thick dimensions to a optimized thin range (5-20 micrometers). This parameter optimization maintains the barrier's protective function against Sn diffusion while minimizing material cost and improving ease of manufacture.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If tubular method is used with niobium alloy tubing to prevent contamination, then copper jacket contamination is reduced, but manufacturing cost increases due to limited availability and high cost of niobium alloy tubing

Engineering Contradiction:
Improvecopper jacket contaminationVSAvoidmanufacturing cost
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The invention replaces expensive, limited-availability niobium alloy tubing with a thin, easily manufacturable niobium barrier layer that can be applied through conventional processes. This thin barrier provides sufficient protection against contamination while being significantly more cost-effective and available than niobium alloy tubing.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If thick niobium barrier is used to suppress reaction, then current carrying capacity is maintained, but manufacturing cost increases

Engineering Contradiction:
Improvecurrent carrying capacityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention optimizes the niobium barrier thickness parameter to a thin range (5-20 micrometers) that maintains sufficient suppression of Sn diffusion to protect copper jacket integrity and preserve current carrying capacity, while dramatically reducing the amount of expensive niobium material required compared to thick barriers.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If double extrusion and multi-step drawing process are used in RIT method, then subelement multi-filament billet is produced, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvefilament countVSAvoidprocess steps
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention merges the barrier layer formation with the extrusion process itself, creating the thin niobium barrier as an integral part of the subelement structure during a single extrusion operation. This eliminates the need for separate barrier deposition steps and reduces the overall number of process steps compared to traditional RIT method.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The extrusion process is designed to simultaneously achieve multiple functions: forming the subelement geometry, creating the filament bundle structure, and depositing the thin niobium barrier layer. This multi-functionality reduces process complexity and manufacturing cost while maintaining high filament count productivity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 method reduces production costs and enhances current carrying capacity while maintaining performance comparable to existing methods, offering a more efficient and cost-effective superconductor manufacturing process.

Implementation Method 1

The reduced metal assembly is reaction heat treated so that the unreacted Nb undergoes a phase transformation to a reacted superconductor

Methodology Applied
Scientific EffectPhase transformation: Phase Change

Implementation Method 2

The metal assembly precursor is reduced via cold drawing to produce a reduced metal assembly

Methodology Applied
Scientific EffectCold drawing: Cold-forming

Implementation Method 3

The metal assembly precursor includes a diffusion blocking layer between the plurality of conductor elements and the hollow copper support element

Methodology Applied
Scientific EffectDiffusion blocking: Diffusion Barrier

Data Source

PatentEP3750173B1Methods for manufacturing a superconductor
Publication Date: 2025.07.30 LUVATA WATERBURY INC
  • EP3750173B1 patent drawingFigure 1
  • EP3750173B1 patent drawingFigure 2
  • EP3750173B1 patent drawingFigure 3~4

AI summary

A method for manufacturing a superconductor is described. A metal assembly precursor can be formed within a hollow copper support element. Forming the metal assembly precursor within a hollow copper support element by positioning a plurality of conductor elements about a core including Sn to provide a first plurality of inner interstitial spaces between the plurality of conductor elements between the core and conductor elements and a second plurality of outer interstitial spaces between the hollow copper support element and the core, the plurality of conductor elements including unreacted Nb. The metal assembly precursor can be reduced via cold drawing to produce a reduced metal assembly. The reduced metal assembly can be reaction heat treated so that the unreacted Nb undergoes a phase transformation to a reacted superconductor.