HIGH TEMPERATURE SUPERCONDUCTING COMPOSITES

A PROGRAM TO DEVELOP A HIGH-TC COMPOSITE WITH THE SUPERCONDUCTING PERFORMANCE AND MECHANICAL PROPERTIES NECESSARY FOR PRACTICAL SPACEBORNE APPLICATIONS IS PROPOSED. A MODIFIED SOL-GEL TECHNIQUE WILL BE DEVELOPED FOR FABRICATING CONTINUOUS FILAMENT HIGH-TC AND HIGH-JC COMPOSITES STABILIZED WITH AN ALUMINUM MATRIX. IN ORDER TO ACHIEVE USEFUL CURRENT DENSITIES, THE MICROSTRUCTURE OF THE SUPERCONDUCTING FILAMENTS WILL BE TAILORED TO ACCOMMODATE THE CRYSTALLOGRAPHIC ORIENTATION DEPENDENCE OF JC, SUPER-CONDUCTIVITY ACROSS GRAIN BOUNDARIES, MAGNETIC FIELD DEPENDENCE OF JC, AND THE STABILIZATION REQUIREMENTS OF THE SUPERCONDUCTING STATE. THE PROCESS PROMOTES THE FORMATION OF HIGH-JC FILAMENTS THROUGH CRYSTALLOGRAPHIC TEXTURING DEVELOPED FROM MOLECULAR LEVEL SOL CHEMISTRY. HIGH-JC FILAMENTS WILL BE PRODUCED BY LOW TEMPERATURE EXTRUSION OF A HIGHLY ORIENTED PRECURSOR POLYMER FOLLOWED BY A REACTION HEAT TREATMENT TO FORM THE HIGH-TC PHASE. THERMALLY AND MECHANICALLY STABILIZED COMPOSITES WILL BE FORMED BY LIQUID METAL INFILTRATION OF MULTIFILAMENT BUNDLES. THE PHASE I PROGRAM SEEKS TO DEMONSTRATE THE PRODUCTION OF CRYSTALLOGRAPHICALLY ORIENTED HIGH-JC FILAMENTS OF YBA2CU307-X. MULTIFILAMENT PRODUCTION AND COMPOSITE FABRICATION WOULD BE UNDERTAKEN IN PHASE II.