Multifilamentary Nb-Nb3Sn composite by liquid infiltration method: Superconducting, metallurgical, and mechanical properties

A rapid solid-liquid reaction mechanism has been used to form A15 Nb
3
Sn in the liquid-infiltration processed Nb-Sn wire. Small, equiaxed A15 grains across the fine reacted filaments of 0.2-1.0 μm thickness were revealed with the transmission electron microscopy studies. A uniform Sn concentration near the stoichiometry was found in the A15 region. High inductive T
c
's of 17.9K with sharp transition widths (<0.3K) and excellent overall J
c
's of 10
⁴
A/cm
²
at 19T and 4.2K were achieved. Mechanical properties of the reacted wire are no worse than those of typical commercial bronze-process Nb
3
Sn conductors, and ε
irrev
is slightly higher.