Production of superconducting Nb/sub 3/Sn wire using Nb or Nb(Ti) and Sn(Ga) solid solution powders

摘要

Superconducting Nb/sub 3/Sn wire was produced by a powder metallurgy method using Nb or Nb-2.9 at.% Ti powder in combination with Sn-x at.% Ga powders (x=3, 4.2, 6.2, and 9.0). Ga additions to the Sn caused considerable solid solution hardening, which improved its workability. It made the Nb-Sn(Ga) powder combination convenient for swaging and extensive wire drawing. Anneals at 950 degrees C produced wires with an overall J/sub c/ of 10/sup 4/ A/cm/sup 2/ at 21.9 T for wires with both Ti in the Nb and 6.2 at.% Ga in the Sn. Comparison of this wire with best Nb(Ti)-Cu-internal Sn(Ti) shows a higher J/sub c/ per A15 area, especially in fields of 22 T and above.