Fabrication of reinforced superconducting wires
In various embodiments, superconducting wires feature assemblies of clad composite filaments and/or stabilized composite filaments embedded within a wire matrix. The wires may include one or more stabilizing elements for improved mechanical properties.
1. A superconducting wire comprising:
a wire matrix comprising Cu;
embedded within the wire matrix, a stabilizing element comprising a stabilizing core comprising a Ta alloy or a Nb alloy and, surrounding the stabilizing core, a stabilizing cladding comprising only Cu and unintentional impurities; and
a plurality of composite filaments embedded within the wire matrix and surrounding the stabilizing element,
wherein:
each composite filament comprises (i) a plurality of monofilaments and (ii) a composite-filament cladding comprising Cu surrounding the plurality of monofilaments,
each monofilament comprises a superconducting monofilament core comprising Nb and, surrounding the superconducting monofilament core, a monofilament cladding comprising Cu,
the stabilizing element is disposed proximate a radial center of the wire,
the stabilizing element extends through an axial dimension of the wire, and
the stabilizing element is disposed in contact with at least some of the composite filaments.
2. The wire of claim 1 , wherein the stabilizing element is the only stabilizing element embedded within the wire matrix.
3. The wire of claim 1 , wherein the stabilizing element occupies at least 2% of a cross-section of the wire.
4. The wire of claim 1 , wherein the stabilizing core is the only stabilizing core of the stabilizing element.
5. The wire of claim 1 , wherein a width of the stabilizing element is approximately equal to a width of one of the composite filaments.
6. The wire of claim 1 , wherein a width of the stabilizing core is greater than a width of one of the monofilaments.
7. The wire of claim 1 , wherein each monofilament core comprises Nb—Ti.
8. The wire of claim 1 , wherein each monofilament core comprises Nb 3 Sn.
9. The wire of claim 1 , wherein the stabilizing core of the stabilizing element comprises Ta-3W.
10. The wire of claim 1 , wherein the stabilizing core of the stabilizing element occupies less than approximately 20% of the cross-section of the wire.
11. The wire of claim 1 , wherein the stabilizing core comprises an alloy of Ta with at least one of W, C, or N.
12. The wire of claim 1 , wherein the stabilizing core comprises an alloy of Nb with at least one of Hf, Ti, Zr, Ta, V, Y, Mo, or W.
13. The wire of claim 1 , wherein the stabilizing core includes only the Ta alloy or the Nb alloy and one or more unintentional impurities.
14. The wire of claim 1 , wherein the stabilizing cladding consists of Cu.
15. The wire of claim 1 , wherein the stabilizing element is hexagonal in cross-section.
16. A method of forming a mechanically stabilized superconducting wire, the method comprising:
providing a plurality of monofilaments each comprising a monofilament core comprising Nb and, surrounding the monofilament core, a monofilament cladding comprising Cu;
providing a stabilizing element comprising a stabilizing core comprising a Ta alloy or a Nb alloy and, surrounding the stabilizing core, a stabilizing cladding comprising Cu;
fabricating a plurality of composite filaments by, for each composite filament, (i) assembling a plurality of the monofilaments into a monofilament stack, (ii) surrounding the monofilament stack with a composite-filament cladding comprising Cu, (iii) reducing a diameter of the clad monofilament stack, and (iv) altering a cross-sectional shape of the clad monofilament stack;
after fabricating the plurality of composite filaments, assembling the plurality of composite filaments and the stabilizing element into a composite stack, wherein the stabilizing element (i) is disposed proximate a radial center of the composite stack, (ii) extends through an axial dimension of the composite stack, and (iii) is in contact with at least some of the composite filaments;
surrounding the composite stack with a wire cladding comprising Cu; and
reducing a diameter of the clad composite stack to form a wire comprising:
a wire matrix comprising Cu;
embedded within the wire matrix, a stabilizing element comprising a stabilizing core comprising a Ta alloy or a Nb alloy and, surrounding the stabilizing core, a stabilizing cladding comprising only Cu and unintentional impurities; and
a plurality of composite filaments embedded within the wire matrix and surrounding the stabilizing element,
wherein:
each composite filament comprises (i) a plurality of monofilaments and (ii) a composite-filament cladding comprising Cu surrounding the plurality of monofilaments,
each monofilament comprises a superconducting monofilament core comprising Nb and, surrounding the superconducting monofilament core, a monofilament cladding comprising Cu,
the stabilizing element is disposed proximate a radial center of the wire,
the stabilizing element extends through an axial dimension of the wire, and
the stabilizing element is disposed in contact with at least some of the composite filaments.
17. The method of claim 16 , wherein each monofilament is provided by a process comprising (i) disposing a rod comprising Nb into a tube comprising Cu to form a clad rod, and (ii) reducing a diameter of the clad rod.
18. The method of claim 16 , wherein providing the stabilizing element comprises (i) disposing a rod comprising the Ta alloy or the Nb alloy into a tube comprising Cu to form a clad rod, and (ii) reducing a diameter of the clad rod.
19. The method of claim 16 , further comprising (i) disposing Sn within or on the wire and (ii) annealing the wire to form a Nb 3 Sn phase within the wire.