Fabrication of multifilamentary Nb3(Al,Ge) wires through a modified jelly roll process

Nb/Al-Ge alloy composites were fabricated into multifilamentary wires through a modified jelly roll (MJR) process. A Nb mesh sheet was used as the Nb component. An Al-Ge alloy prepared by a conventional casting process was forged and rolled into a sheet of 0.2 mm in thickness. The Nb/Al-Ge composite was prepared by wrapping the Nb mesh sheet together with the Al-Ge alloy sheet around a Nb core into a jelly-roll form. The MJR composite was encased in a Cu-Ni alloy tube of which the outer diameter was 43 mm. The resulting composite was hydrostatically pressed and extruded into a rod of 18 mm in diameter. A Nb barrier was then inserted between the MJR and the Cu-Ni jacket. The composite rod was swaged and drawn into a wire without any intermediate annealing. The wire was able to be drawn down to a very small diameter of 0.1 mm. The cross-sectional configuration of the MJR composite was not much disturbed by the fabrication. An onset T_c of 19.3 K has been achieved