Fabrication of Ni-5at%W Long Tapes for Coating Conductors

A 100-meter-long Ni-5at%W (Ni5W) alloy tape with similar to 66 mu m thickness has been fabricated by rolling assisted bi-axially textured substrate route technique (RABiTS). A 10 m long section was taken from the original piece and recrystallized in a home-designed reel-to-reel heat treatment system. XRD texture characterization shows that the average content of rolling textures is 63.8% (<= 10 degrees) before annealing, and the average FWHM values of the in-plane and out-of-plane texture over the annealed tape length are 7.2 and 6.1, respectively. Moreover, EBSD analyses indicate that the content of the cube texture reaches 98.7% (<= 10 degrees) and that of the grain boundaries exceeds 87.7% (<= 10 degrees). In the cold-rolling process, increasing the reduction in the first pass while changing to another mill can effectively reduce the broken cases. These results prove that the process has the ability to yield Ni-5at%W tapes with a high cube texture and homogeneous qualities, which will be able to satisfy the requirements of the YBa2Cu3O7-x, superconductive layer.