Study on the Microstructure of High Magnetic Field (≥ 9 T) NbTi Superconducting Wire

NbTi superconducting Wire has the advantage of excellent processing characteristics, stable superconducting properties, and low cost. It has been widely used for low magnetic fields of <9 T. To increase the stability and reduce the cost of superconducting magnets, it is necessary to improve the critical current density at high magnetic fields (≥9 T) of the NbTi superconducting wire. Therefore, this research focuses on the processing procedure and obtain samples with the higher Jc (4.2 K, 9 T) of 738 A/mm
²
. In addition, in this article, the microstructure of two typical samples with different Jc (4.2 K) at magnetic fields of 4 T and 9 T is analyzed. It is shown that the critical current density at high magnetic fields (≥9 T) needs the larger width and less area ratio of α-Ti phase.