Hot extrusion and fabrication of powder metallurgy processed superconductors

In order to demonstrate the potential of powder metallurgy (P/M) process for fabrication of high field superconductors, intermediate scale (5 cm o.d. 15 cm long) billets were fabricated and processed industrially by hot extrusion. Precompacted powder composites of Cu-45wt%Nb and Cu-45wt%(Nb-1.2wt%Ti), each weighing more than 2kg, were extruded as solid or tubular bars. Sections of the extruded Cu-Nb and Cu-Nb(Ti) bars were successfully processed to 0.25 mm o.d. wires. Internal Sn sources were used to produce multifilamentary Nb
3
Sn and Nb
3
Sn(Ti). The high field critical current density was comparable to that obtained from small scale cold hydrostatic extrusion processing. The results suggest that large scale extrusion processing should produce high performance P/M processed superconductors.