Multifilament Superconductor, as well as Method for its Production

• US 20090038822A1
• Filed: 04/16/2008
• Published: 02/12/2009
• Est. Priority Date: 04/18/2007
• Status: Active Grant

• Current Assignee: European Advanced Superconductors GmbH & Co. KG.
• Original Assignee: European Advanced Superconductors GmbH & Co. KG.
• Inventors: Abaecherli, Vital, Auer, Alfred, Szulczyk, Andreas, Ehser, Horst, Thoener, Manfred
• Granted Patent: US 8,173,901 B2
• Time in Patent Office: Days
• US Class Current: 174/125.100
• CPC Class Codes: H10N 60/0184 of devices comprising intermetallic compounds of type A-15, e.g. Nb3Sn
• CPC Class Codes: H10N 60/20 Permanent superconducting devices
• CPC Class Codes: Y10T 29/49014 Superconductor

Abstract

A multifilament superconductor (1) has a core area (2), several superconductor filaments (7) and reinforcement filaments (6). The superconductor filaments (7) and the reinforcement filaments (6) are arranged, so that they have a regular two-dimensional matrix (5) in the cross-section of core area (2). The reinforcement filaments (6) consist of tantalum or a tantalum alloy, and the superconductor filaments (7) each have a core (8), made from a powder metallurgically produced superconductor, which is enclosed by an inner shell (9), made of a non-superconducting metal or a non-superconducting alloy. The core area (2) is enclosed by an outer shell (3), made of a non-superconducting metal or a non-superconducting alloy.

Claims

1. A method for production of a reinforced multifilament superconductor, comprising the following steps:

Preparation of several superconductor rods, each of which comprise at least one powder metallurgical core from the elements of a metallic superconductor core, wherein the core is enclosed by an inner shell made of a non-superconducting metal or a non-superconducting alloy,

Preparation of several reinforcement rods, each of which consists of tantalum or a tantalum alloy,

Arrangement of the superconductor rods and the reinforcement rods into a bundle, the superconductor rods and the reinforcement rods being arranged such that they form a regular two-dimensional matrix in the cross-section of the bundle,

Enclosure of the bundle with the outer shell made of a non-superconducting metal or a non-superconducting alloy,

Deformation of the enclosed bundle with reduction of the cross-section of the enclosed bundle to produce a multifilament,

Annealing of the deformed multifilament at a temperature and for a sufficient period of time, so that superconducting phases are formed in the powder metallurgical cores.

2. Method according to claim 1, wherein for formation of the bundle, the reinforcement rods are arranged in the matrix around the superconductor rods.

3. Method according to claim 1, wherein the reinforcement rods are arranged only in the edge area of matrix.

4. Method according to claim 1, wherein the reinforcement rods are arranged with an azimuthal symmetry in matrix.

5. Method according to claim 1, wherein the reinforcement rods are arranged distributed over the cross-section of the matrix.

6. Method according to claim 5, wherein the reinforcement rods are arranged with axial symmetry in matrix.

7. Method according to claim 1, wherein the superconductor rods and the reinforcement rods have essentially the same cross-sectional surface.

8. Method according to claim 1, wherein the superconductor rods, as well as the reinforcement rods, each have a hexagonal cross-section.

9. Method according to claim 1, wherein the percentage of reinforcement rods lies between about 10% and about 25% of the total number of rods of the matrix.

10. Method according to claim 1, wherein the powder metallurgical cores of the superconductor rods each have the components of an A15 superconductor.

11. Method according to claim 1, wherein the powder metallurgical cores of the superconductor rods each have powder from NbTa, Nb₂Sn and Sn.

12. Method according to claim 1, wherein annealing is carried out at 500°

C. to 700°

C. for 2 to 20 days.

13. Method according to claim 1, wherein the reinforcement rods each have a core made of tantalum or a tantalum alloy, enclosed with a shell made of Cu.

14. Method according to claim 1, wherein the reinforcement rods are produced by extrusion.

15. Method according to claim 1, wherein the superconductor rods are produced by a powder-in-tube method.

16. Method according to claim 1, wherein the multifilament is produced with the shape of a wire or the shape of a strip by chipless machining of the enclosed bundle.

17. Multifilament superconductor comprising a core area, several superconductor filaments and reinforcement filaments, wherein the superconductor filaments and the reinforcement filaments are arranged such that they have a regular two-dimensional matrix in the cross-section of the core area, and the core area being enclosed by an outer shell made of an non-superconducting metal or a non-superconducting alloy, wherein the reinforcement filaments consist of tantalum or a tantalum alloy, and the superconductor filaments each have a core made of a powder metallurgical superconductor, which is enclosed by an inner shell made of a non-superconducting metal or a non-superconducting alloy.

18. Multifilament superconductor according to claim 17, wherein the multifilament superconductor has the shape of a wire or strip.

19. Multifilament superconductor according to claim 17, wherein the reinforcement filaments are arranged in the matrix or on the superconductor filaments.

20. Multifilament superconductor according to claim 17, wherein the reinforcement filaments are arranged only in the edge area of matrix.

21. Multifilament superconductor according to claim 17, wherein the reinforcement filaments are arranged with azimuthal symmetry in matrix.

22. Multifilament superconductor according to claim 17, wherein the reinforcement filaments are arranged distributed over the cross-section of matrix.

23. Multifilament superconductor according to claim 22, wherein the reinforcement filaments are arranged with axial symmetry in matrix.

24. Multifilament superconductor according to claim 17, wherein the superconductor filaments and the reinforcement filaments each have roughly the same cross-sectional area.

25. Multifilament superconductor according to claim 24, wherein the percentage of reinforcement filaments lies between about 10% and about 25% of the total number of filaments of the matrix.

26. Multifilament superconductor according to claim 17, wherein the superconductor filaments, as well as the reinforcement filaments, each have a hexagonal cross-section.

27. Multifilament superconductor according to claim 17, wherein the cores of superconductor filaments each have the components of an A15 superconductor.

28. Multifilament superconductor according to claim 27, wherein the cores of the superconductor filaments each have (Nb, Ta)₃Sn or Nb₃Sn or Nb₃Al or Nb₃Si or Nb₃Ge of V₃Si or V₃Ga.

29. Multifilament superconductor according to claim 17, wherein the reinforcement filaments each have a core of tantalum or a tantalum alloy, enclosed with a shell made of copper.