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

Abstract

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