DEVELOPMENT OF NIOBIUM-TITANIUM-TANTALUM ARTIFICIAL PINNING CENTER SUPERCONDUCTORS FOR VERY HIGH FIELD APPLICATIONS

THE BEST ENCHANCEMENT IN CRITICAL MAGNETIC FIELD (HC2) FOR NIOBIUM TITANIUM (NBTI) ALLOYS HAS BEEN FOUND FOR A 15 TO 25 WT. % TERNARY ADDITION OF TANTALUM. THE PRECISE ALLOY COMPOSITION FOR THE BEST COMBINATION OF CRITICAL TEMPERATURE (TC), HC2 PRECIPITATION KINETICS, CRITICAL CURRENT (JC) AND DUCTILITY ARE STILL OF CONSIDERABLE DEBATE BECAUSE NBTITA ALLOYS TO DATE HAVE NOT SIGNIFICANTLY OUTPERFORMED BINARY NBTI. A PROCESS HAS BEEN DEVELOPED FOR THE MANUFACTURE OF NBTI COMPOSITE SUPERCONDUCTORS USING AN ARTIFICIAL PINNING CENTER (APC) APPROACH. THE APC PROCESS HAS BEEN EXTENDED TO NBTITA MATERIAL, AND MODEL CONDUCTORS SHOW AN ADEQUATE DUCTILITY AND SMILAR JC TO BINARY APC COMPOSITES. PHASE I WILL WORK TO ESTABLISH THE BEST RAW MATERIAL CONFIGURATION AS WELL AS THE THERMAL AND MECHANICAL PROCESSES IN MODEL APC NBTITA SUPERCONDUCTOR MATERIAL. THE PHASE I AND THE ANTICIPATED PHASE II EFFORTS WILL COMPLEMENT AND BUILD UPON THE EXISTING TERNARY CONDUCTOR RESEARCH AND COULD RESULT IN A PROVEN COMMERCIAL PROCESS FOR TERNARY APC CONDUCTOR. TERNARY APC CONDUCTORS HAVE GREATER POTENTIAL FOR HIGHER JC AT OPTIMAL COMPOSITIONS THAN TERNARY APPROACHES USING MELTED ALLOY.