Method of manufacture of multifilamentary intermetallic superconductors
AssigneeAirco, Inc.
InventorWilliam G. Marancik
Life of this patent
Estimating the term…
Abstract
An improved method for manufacture of multifilamentary superconductors of the A.sub.3 B type having the A-15 crystal structure, such as Nb.sub.3 Sn, is disclosed in which rods or wires of the A material are disposed throughout a matrix consisting of Cu and the B material in substantially elemental form. The matrix is formed by compaction of powders of Cu; powders of the B may be mixed therewith or the B material may be infiltrated into pores between the individual Cu particles after compaction. The resultant composite has A, B and Cu distributed uniformly throughout its volume and can be worked to any desired final shape and size for heat treatment to form the A.sub.3 B material without intermediate annealing steps.
Claims15
A method for manufacturing a multifilamentary superconductor having the composition A.sub.3 B and the A-15 crystal structure, comprising the following steps:
- encasing one or more rods or wires of the A material within a sheath of a material consisting essentially of a compacted composite of Cu and the B material said composite being formed by compaction of Cu powder into a porous matrix, sintering said porous matrix, and dipping said porous matrix into a bath of the B material, whereby said B material is infiltrated into the pores in said sintered porous Cu matrix;
- working the sheathed rods to firmly consolidate said composite upon said rods;
- packing a plurality of the worked sheathed rods together;
- further working the assembled plurality of sheathed rods to a desired final shape and size;
- and
- subjecting the worked assembly to a heat treatment for a time and at a temperature such that the compound A.sub.3 B is formed at the interfaces between the rods of the A material and the composite material.
A method of manufacture of a multifilamentary superconductor of the type in which a predetermined number of fine filaments of intermetallic superconductive material having the composition A.sub.3 B and the A-15 crystal structure are embedded in a matrix of normal conductor, which comprises:
- disposing wires of the A material in a matrix consisting of Cu and the B material, said Cu and said B material having substantially unalloyed, said matrix being formed by compaction of elemental powder of Cu to form a porous matrix and susequent infiltration of the B material into the pores of said porous matrix;
- working the assembly of wires of the A material and said matrix to a desired final shape and size;
- and
- performing a heat treatment to form said superconductive compound at the interfaces between said wires and said composite matrix.
The method for manufacture of multifilamentary superconductive wire, comprising the steps of:
- preparing a composite material, consisting essentially of Cu and Sn, by compaction of powders;
- sheathing rods of Nb in strips of said composite material;
- drawing said sheathed Nb rods to an intermediate size;
- packing a plurality of said drawn rods within a generally tubular structure;
- reducing said tubular structure containing said rods to a desired final shape and size;
- and
- heat treating said structure at its final size to form Nb.sub.3 Sn about said rods of Nb.
In a method of manufacture of a multifilamentary superconductor of the A-15 type having the composition A.sub.3 B, comprising the steps of forming a precursor assembly comprising Cu, A and B, said A being disposed in filamentary form substantially uniformly throughout a matrix of Cu and B, said matrix being formed by compaction of Cu powder into a porous matrix, sintering said porous matrix and subsequent infiltration of the B material into the pores of said porous matrix, working said assembly to a desired finished shape and size, and performing a reaction heat treatment to form A.sub.3 B at the interfaces between said A filaments and the matrix, the improvement which comprises said Cu and B materials being substantially not alloyed during said working, and said B material being disposed uniformly throughout said matrix.
Dependencies are inferred from the claim text.