Production of Jelly-Roll Process Nb3Al Multifilamentary Superconducting Wire Using Warm Hydrostatic Extrusion

50806-98-I Production of Jelly-Roll Process Nb3Al Multifilamentary Superconducting Wire Using Warm Hydrostatic Extrusion--Supercon, Inc., 830 Boston Turnpike, Shrewsbury, MA 01545-3301; (508) 842-0174 Mr. Mark K. Rudziak, Principal Investigator Ms. Elaine Drew, Business Official DOE Grant No. DE-FG02-98ER82677 Amount: $74,991 The high energy physics community requires the development of superconducting wires for use in magnets generating magnetic fields of 15T and above. Currently, Nb3Sn is the only commercially available superconductor capable of operating at such high fields. Nb3Al is also suitable for high field uses, and it has much greater strain tolerance than Nb3Sn; however, multifilament wire fabrication is much more difficult than for Nb3Sn. This program seeks to develop a reliable fabrication route for Nb3Al multifilament wire. The principal difficulty in fabricating multifilament jelly-roll Nb3Al conductor is obtaining sufficient inter-filament bonding within the composite to allow for reliable wire drawing. This project will use warm hydrostatic extrusion to promote inter-filament bonding in multifilament Nb-Al jelly-roll composites. In Phase I, Nb-Al jelly-roll monofilament wire will be fabricated and restacked into multifilament billets. These billets will be hydrostatically extruded under varying conditions of temperature (up to 300¿C) and reduction (up to 16:1 by area). Bonding in the composites will be evaluated, reaction heat treatments will be applied to the most fabricable composites, and resulting superconducting properties will be measured. Commercial Applications and Other Benefits as described by the awardee: High performance, multifilamentary Nb3Al conductor would offer an attractive alternative to Nb3Sn in high energy physics particle accelerators and fusion machines. Commercially, such a conductor would find application in nuclear magnetic resonance magnets that are currently fabricated using Nb3Sn wire. The excellent strain tolerance of Nb3Al would make it feasible to use the react-and-wind technique for magnet fabrication, providing cost savings in manpower, equipment, and tooling._