Reinforced {110} textured Ag/Ni composite ribbons for biaxially oriented YBCO coated tapes

New, mechanically reinforced, {110} textured Ag composite ribbons were fabricated as possible inexpensive substrates for coated conductors without any buffer layer. The key part of this work was the use of a thin but textured Ag outlayer on an AgMg, Ni, or Ni alloys core that ensures the mechanical reinforcement while decreasing the amount of Ag. A thin Cu (50 µm) foil was intercalated between rectangular Ag and AgMg, Ni, or Ni alloys pieces to obtain a tough bond. After sintering, the ingots sustained a cold plastic deformation up to thicknesses of 300, 100 and 50 µm without any intermediate annealing. The prepared composite ribbons were then recrystallized to obtain the {110} texture in the top Ag layer. For the Ag/AgMg ribbons, a further annealing in flowing oxygen was performed to reinforce the ribbons by an internal oxidation process in the AgMg layer without changing the {110}011 texture in the Ag outerlayer. A unique and stable {110}011 texture was obtained in Ag/Ni composite ribbons after annealing at 800 °C. The highest degree of texture was observed in 300 µm thick Ag/Ni ribbon, x-ray orientation distribution function and electro backscattered diffraction (EBSD) analysis of the top Ag layer in this ribbon revealed a sharp {110}011 texture with an in-plane misorientation angle of 10-15°. Meanwhile, a promising {110}011 texture was also found in 50 µm thick ribbons with 25° in-plane misorientation angle. In the last case, a substrate with no more than 16 µm of the textured Ag layer was produced by this new technique, which decreased the total amount of Ag by 40% compared with pure Ag ribbons of the same thickness.