Ultrasonic Drawing of Advanced A15 Strand, Piece-Length Enhancement, Bonding, and Stabilizer Attachment

65493 Future high field (15T+) dipole magnets will require higher performance superconductors, and long lengths will be needed to reduce the cost of these conductors. The A15-type conductors are the most likely superconductors to fulfill this need, but it is very difficult to process the wire without breaks, especially when billet sizes are increased to produce 5-25 km lengths. This processing difficulty is related to the hardness of the multifilamentary composite and the bonding of the filaments. This project will investigate an ultrasonic processing technique to reduce drawing forces and increase bonding between the filaments. Phase I demonstrated several ultrasonic wire drawing equipment designs. The ultrasonic drawing forces were shown to be as little as 55% less compared to the non-ultrasonic wire drawing A15 type superconductors. In addition, ultrasonic wire drawing was demonstrated for multi-filament composites, which was not possible with conventional conical dies. Phase II will design and build a high power ultrasonic wire drawing setup. The optimum ultrasonic wire drawing parameters, for preventing filament breakage and improving inter-filament bonding, will be determined for multi-filament A15 superconducting composites. Commercial Applications and Other Benefits as described by the awardee: Although the largest market should be for accelerator and fusion magnets, high field magnets (above 5 tesla) should also have applicability for MRI, NMR, high gradient magnetic separators, and SMES applications.