Method of fabricating a composite multifilament intermetallic type superconducting wire

Claim 1

THE IMPROVED METHOD OF FORMING AN INTERMETALLIC NB3SN SUPERCONDUCTOR IN A NORMAL RESISTANCE CU METAL MATRIX, COM: PRISING THE STEPS OF: A PREPARING A NB-CU COMPOSITE STRUCTURE HAVING AT LEAST ONE LONGITUDINAL EXTENDING MEMBER OF A FIRST MALLEABLE PURE MTAL NB COMPONENT OF A SPECIFIC TWO-COMPONENT INTERMETALLIC NB3SN SUPERCONDUCTOR IN A SECOND PURE MALLEABLE CU METAL THAT DOES NOT CONTAIN THE SPECIFIC COMPLIMENTARY METAL SN COMPONENT OF SAID TWOCOMPONENT INTERMETALLIC SUPERCONDUCTOR, SAID NB COMPONENT PCCUPYING 30% TO 40% OF THE CROSSSECTIONAL AREA OF THE COMPOSITE STRUCTURE; B. COLD-WORKING SAID COMPOSITE STRUCTURE, INCLUDING THE FIRST AND SECOND PURE MTALS, WITHOUT INTERMEDIATE ANNEALING, TO FORM AN ENLONGATED CONDUCTOR SELECTED FROM THE GROUP CONSISTING OF TAPES AND WIRES, INCLUDING AT LEAST ONE COMPOSITE STRUCTURE WITH A MXIMUM THICKNESS OF UP TO ONLY 60 MILS; C. TRANSPORTING SAID CONDUCTOR THROUGH A MOLTEN TIN BATH AT 240*C TO COVER SAID CONDUCTOR WITH SAID SPECIFIC COMPLIMENTARY COMPONENT OF SAID TWO-COMPONENT INTERMETALLIC SUPERCONDUCTOR FOR FORMIN A SOLID SOLUTION ALLOY HAVING A SN CONCENTRATION OF BETWEEN 3 ATM % AND 1.5 ATM % THAT IS REQUIRED FOR THE FURTHER PROCESSING STEPS; D. TRANSPORTING THE SN COVERED CONDUCTOR INTO A FURNACE HAVING A PROTECTIVE ATMOSPHERE AT SLIGHTLY MORE THAN 1 ATM. PRESSURE TO HEAT THE SN COVERED CONDUCTOR TO BE TWEEN 500*C AND 800*C FOR UP TO FIVE MINUTES TO PRODUCE THE SOLID SOLUTION ALLOY AS A NORMAL RESISTANCE MRIX CONTAINING ALL THE COMPLIMENTARY COMPONENT; E. HEATING THE CONDUCTOR CONTAINING THE SOLID SOLUTION ALLOY FOR AT LEAST 20 HOURS AT BETWEEN 550*C AND 800*C TO DIFFUSE THE SN FROM THE MTRIX TOWARD THE NB COMPONENT UNTIL THE INTERMETALLIC SUPRCONDUCTOR IS FORMED IN SITU AS A BENDABLE LAYER ONLY UP TO ONE-QUARTER OF THE WAY INTO THE OUTER SURFACE OF THE FIRST MALLEABLE PURE METAL COMPONENT; AND F. BENDING THE SUPERCONDUCTOR AROUND A MANDREL TO A BENDING DIAMETER OF UP TO ONLY 1.5 INCH FOR PRODUCING A MAGNETIC FIELD AT A CRITICAL CURRENT DENSITY OF UP TO APPROXIMATELY 7.5X10**5 A/CM2.