[en] A rapid solid-liquid reaction mechanism has been used to form A15 Nb₃Sn in the liquid-infiltration processed NbSn 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 /SUB c/ 's of 17.9K with sharp transition widths (<0.3K) and excellent overall J /SUB c/ 's of 10⁴ A/cm² at 19T and 4.2K were achieved. Mechanical properties of the reacted wire are no worse than those of typical commercial bronze-process Nb₃Sn conductors, and epsilon /SUB irrev/ is slightly higher