Study on Fabrication of Ni-5at.%W long Tapes for Coated Conductors

Abstract:

A 100-meter-long Ni-5at.%W (Ni5W) alloy tape with ~66μm thickness had been fabricated successfully by Rolling assisted bi-axially textured substrate route technique. A 10m long section was taken from the original piece and recrystallized in a home-designed reel-to-reel heat treatment system. The XRD texture characterization showed that the average content of rolling textures was 63.8% (≤10°) before annealing, and the average FWHM values of the in-plane and out-of-plane texture over the annealed tape length were 7.2° and 6.1° respectively. Moreover, EBSD analyses determined that the content of the cube texture reached 98.7% (≤10°) and that of the grain boundaries exceeded 87.7% (≤10°). 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 will prove that the process described in this work 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 YBCO superconductive layer.