Fabrication of Reinforced and Biaxially Textured NiW Alloy Substrates by Spark Plasma Sintering Technique

The key requirement for the substrates employed in coated conductors is using highly cube textured and weakly magnetic as well as strengthened materials. In this work, a tri-layer of composite substrate, as a substitute for the traditional substrate architecture, was designed and obtained by sintering two pieces of Ni-5at.% W (or Ni-7at.% W) outer layers on both sides of a Ni-12at.% W mixed powder (as an inner layer) together using an advanced spark plasma sintering (SPS) technology, followed by cold rolling and annealing. The sharp cube texture was obtained in both kinds of composite substrates by optimizing rolling and recrystallization processes. The percentage of the cube texture component on the Ni5W outer layer of the Ni5W/Nil2W/Ni5W composite substrate was higher than 95.4% within a misorientation angle of 10deg from EBSD measurements. Moreover, the yield strength of this composite substrate exceeds 300 MPa, while the saturation magnetization is reduced dramatically.