The preparation method of wide plate width barrier layer niobium sheet for superconducting wire includes: first, the niobium plate is rolled along a fire after reversing rolling, and then the niobium plate is obtained by grinding, sanding, pickling, shearing and vacuum annealing; Second, the niobium plate with tension rolling, and then in turn for grinding, sanding, pickling, shearing and vacuum annealing heat treatment to get wide plate width barrier layer niobium sheet. This invention USES two rolling process and rolling of large deformation rate, large deformation in the niobium material organization, no deformation of dead zone and the rapid shaping, reduce the effect of niobium surface quality of plate, and combining with control each rolling process after vacuum annealing heat treatment temperature and time, make the deformation of deep reply with complete recrystallization grain size, form a uniform microstructure, The niobium sheet with wide plate width barrier layer has good surface quality, uniform microstructure, small average grain size, small uniform grain range and large elongation, which is suitable for superconducting large scientific equipment.
The role of niobium sheet as a barrier layer for high quality superconducting wire is to prevent the reaction between copper in copper coating and titanium metal to produce Ti-copper compounds and prevent the wire from breaking in the subsequent drawing process. The requirements of the finished superconducting wire are very strict. The diameter of the wire is 100 microns, and the core wire is arranged neatly at the cross section of the wire after stretching, and the deformation is uniform. There is no 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 niobium sheet of the barrier layer in the superconducting wire has uneven structure or surface defects, it is easy to fracture in the subsequent drawing process of the wire, which seriously affects the preparation process of NbTi and Nb3Sn superconducting wire, thus restricting the development of energy manufacturing equipment.
The diameter of superconducting wire is hundreds of microns, and the grain size of the barrier niobium plate stretched into niobium wire is tens of microns, so the number of grains contained in the cross section of a wire is a single digit. If the grain size of the niobium plate is very different, it is easy to cause the superconducting wire to break during the stretching process, affecting the length of the wire. Thus, the niobium belt disclosed in the patent cannot be used for the preparation of superconducting wire used in the superconducting scientific device, and no proprietary technology can be prepared for this purpose of the barrier layer niobium plate.
