Continuous multistrand assembly techniques for Ag clad superconducting wire

A method to continuously combine and deform silver clad superconducting strands has been developed. This technique has been used to fabricate multifilament superconducting tapes consisting of Bi-2223, high temperature superconducting precursors. Results show that silver has the unique ability to be bonded together in a continuous strand process without requiring a protective atmosphere. The approach uses a continuous process to combine relatively fine wires that are aligned in the desired configuration, held in intimate contact and heat-treated to promote metallurgical bonding. Silver grain growth across strand interfaces has been documented in processed tapes and lengths approaching 100 meters have been fabricated. Engineering critical current densities (J/sub c/) as high as 19000 amps/cm/sup 2/ (77 K, self-field, 1 /spl mu/V/cm) have been recorded in short samples.