The invention relates to a preparation method of wide plate width barrier niobium sheet for superconducting wire. The method includes: first, the niobium plate is rolled along one fire and then reversed rolled, and then the niobium plate is obtained by grinding, sanding, pickling, shearing and vacuum annealing; Two, the niobium plate strip tension rolling, and then the grinding, sanding, pickling, shear and vacuum annealing heat treatment to obtain wide plate width barrier niobium plate. The invention adopts the rolling mode of two rolling processes and large deformation rate to make the structure of niobium material have large deformation, no deformation dead zone and rapid processing forming, reducing the influence on the surface quality of niobium plate. At the same time, combined with controlling the temperature and time of vacuum annealing treatment after each rolling process, the deeply deformed grains can recover and completely recrystallize, forming uniform microstructure. The wide plate barrier niobium plates with good surface quality, uniform microstructure, small average grain size, small uniform grain range and large elongation were prepared, which are suitable for large superconducting scientific devices.
The function of barrier niobium plate for high quality superconducting wire is to prevent the copper in the copper sheath from reacting with titanium metal to produce titanium-copper compound and prevent the fracture of the wire in the subsequent tensile process. The requirements of the finished superconducting wire are very strict. The diameter of the wire is 100 microns, and the core wires are arranged neatly at the section of the wire after stretching, and the deformation is uniform. There is no phenomenon of uneven thickness of the core wire. Through the above quality requirements to ensure that NbTi and Nb3Sn superconducting wire work hardening index (n value) to meet the requirements of energy manufacturing equipment. If the barrier layer niobium sheet in superconducting wire has uneven structure or surface defects, it is easy to fracture in the subsequent tensile process of the wire, which seriously affects the preparation process of NbTi and Nb3Sn superconducting wire, thus restricting the development of energy manufacturing equipment.
