Processing and Characterization of Ni Base Coated Superconductor Substrate Tapes With Layered Architecture

Abstract

Ni/Ni-5 at.%Mo and Ni/Ni-5 at.%Mo/Ni multilayer tapes were prepared from elemental powders by a powder metallurgy route for coated superconductor substrate applications. The development of cube texture ({001}(100)) following heavy cold rolling ( ~95%) and annealing has been studied in the Ni side(s) of these multilayer tapes and compared to a nonalloyed Ni tape. Although the deformation textures in the Ni side(s) of these multilayer tapes appear quite similar to that of the nonalloyed Ni tape cold rolled to a similar deformation level, the volume fraction of the cube grains in the Ni side(s) of the multilayer tapes following annealing shows marked improvement as compared to the nonalloyed Ni tape after different annealing treatments. X-ray area mapping from typical cross-sectional areas of the multilayer compacts in the sintered condition reveals significant diffusion of the alloying element Mo from the alloy side(s) to the Ni side. These facts amply corroborate the earlier observation on the beneficial role of Mo on the development of cube texture in Ni. The yield strength of the annealed multilayer tapes shows marked improvement over nonalloyed Ni tapes.