Production of ${\rm Nb}_{3}{\rm Sn}$ Bronze Route Strands With High Critical Current and Their Study

Bronze processed strands, differing by specific layouts, and the Sn content of 14.5 and 15.5 wt% in the matrix, were produced and investigated. In order to optimize the production process the investigation of the mechanical properties of doped and undoped bronze samples was done. The microstructure features of strand samples were explored by means of electron microscopy. X-ray analysis was used to determine the characteristics of phase after diffusion annealing. The current capacity of strands and “n” parameter has been investigated in magnetic fields from 8 T up to 12 T at 4.2 K and it was established that the critical current density is (J
_c
)higher than 900 A/mm
²
(non-copper, diameter 0.82 mm, 4.2 K, 12 T) for the investigated strands with doped bronze matrix.