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

Abstract

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.

Texture and Preferred Orientation

“…The investigation of textures of rolled metal sheets elucidated various types of textures that typically occur in fcc and bcc metals [24]. Metals that are currently under investigation for these applications include nickel, nickel-based alloys, silver and others [18,25,26]. Interestingly, the results on rolling textures recently found application in the preparation of thin-film superconductors on metallic ribbons.…”

“…Suo et al investigated mechanically reinforced Ag composite [25]. This might be achieved by introducing a rolling texture and subsequently recrystallizing the ribbons at higher temperatures.…”

Fabrication of YBCO Films on ${\rm SrTiO}_{3}$ and Textured Ag Substrates by TFA-MOD Method

“…At present, TFA-MOD method, a fast, non-vacuum and low cost technique [1], [2] is widely used to fabricate YBCO long tape on RABiTS Ni alloy substrate with various buffer layers [3], [4]. Moreover, textured silver is also one of the promising substrate for the coated conductors in view of its chemical compatibility with high-materials [5], [6]. Therefore, it would be economically viable and industrially practical to deposit YBCO tape directly on textured Ag substrate without any buffer layers using TFA-MOD technique.…”

Investigation Texture in Ni-W Alloy Substrates for Coated Conductors

“…In order to develop long length of coated tapes with high performance, the RABiTS technique, as one of the most scaled-up, cost-effective as well as promising approach, is of benefit to fabricate robust alloy substrates for CCs in the near future. So far, Ni5W alloy substrates show relatively stronger mechanical strength and reduced ferromagnetism [4] comparing with various RABiTS substrate candidates used for coated conductors, such as pure Ni [5], Cu alloys [6], Ag and Ag alloys [7]. So that it is widely preferred as a commercial substrate material because a very strong cube texture can be developed easily during recrystallization [5].…”