Development of nickel alloy substrates for Y-Ba-Cu-O coated conductor applications

Abstract

Fabrication of long-length, textured substrates constitute a critical step in the successful application of coated High Temperature Superconductors (HTS). Substrate materials stronger than nickel are needed for robust applications, while substrates with non-magnetic characteristics are preferred for AC applications. The present work is thus focused on development of texture in high strength, non-magnetic substrate materials. As the development of cube texture is easier in medium to high stacking fault energy materials, binary alloys based on nickel were evaluated for the present application. High purity alloys were melted and hot/cold worked to obtain thin tapes. The development of texture in these alloys as a function of processing parameters was studied by X-ray diffraction and metallographic techniques. Orientation Imaging Microscopy (OIM) was used to quantify the extent of texture development in these substrates. Results to date on the development of texture by thermo-mechanical processing of these alloys are presented.