Niobium-Titanium Superconducting Wires: Nanostructures by Extrusion and Wire Drawing

Nano-fabrication is not new to the manufacturers of superconducting wires, in fact the dominant commercial superconductor, Nb-Ti, relies on a mechanically induced nano-structure for its remarkable properties. In this paper we show how these wires are manufactured so that their microstructure achieves the same scale as the superconducting vortex spacing. Recent attention on superconductors has emphasized the importance of the critical temperature, that being the temperature below which a material is superconducting. At present the highest temperature superconductor has a critical temperature of 138 K (Hg0.8Tl0.2Ba2Ca2Cu3O8+δ). The most important parameter, however, for commercial application, is the critical current density, which is the maximum current density that a superconductor can carry without dissipating heat. Nb-Ti has become the dominant commercial super-