NbTi Ternary and Quarternary Alloys for High Field (>8T) Applications

40734 November 13, 1996 Supercon, Inc. Niobium titanium (NbTi) has been the most common material used for superconducting magnets. The relative ease with which a NbTi based alloy can be fabricated into a multifilamentary conductor is its most appealing feature. However, because of its critical field of 11-12 T at 4.2 K, its use has been restricted primarily to fields less than 9 T. Recently, the demand for high field magnets has increased. This project will optimize both a ternary and quarternary alloy for 10 T operation at 1.8 K. Phase I will investigate monofilamentary material, thereby eliminating any extrinsic effects, e.g., filament sausaging. In addition, Phase I will explore the NbTi based ternary (Nb-22Ti-22Zr) and quarternary (Nb39Ti-24Ta-6Zr) alloys that exhibited the highest BC2 reported in the literature, evaluate them for use at high magnetic fields, and optimize the parameters for further development. Multifilamentary conductors will be addressed in Phase II. Anticipated Results/Potential Commercial Applications as described by the awardee: This program should result in a ternary or quaternary NbTi-based alloy for use in high field (>8 T), low temperature (1.8 K) applications e.g., quadrupoles for LHC. They should be ideal for use in superconducting magnets for accelerator, fusion and NMR projects.