Advances in the Brass and Stainless Steel Reinforcement of High Temperature Superconducting Wires

Lamination-reinforced Bi2223/Ag (1 G) HTS tapes with mechanical and electrical properties tailored for applications have been developed by applying a strain compensation model and statistical analysis to material selection and lamination optimization. Stainless steel reinforced wire has been established with double-bend tolerance improved to 38 mm diameter from 50 mm, tensile strain tolerance improved to 0.4% from 0.35% and 10% higher current density. For applications requiring high-current windings, a prototype reinforced wire has been developed with two co-laminated HTS tapes and double the standard critical current (to 255 A at 77 K). Brass laminated hermetic 1 G wire has also been established for cable applications with over 200 km manufactured and shipped. A wide range of brass tempers can be used to tailor mechanical properties for different requirements. Reliable capability for producing low resistance, robust hermetic splices has been qualified for brass laminated wire in order to efficiently make custom long length wires and repair wire in the field or during manufacture of applications such as cables.