Abstract

Biaxially textured Ni tapes were fabricated by a cold working and recrystallization heat treatment processes from powder compact rods. The processing parameters associated with the cube texture formation in Ni tapes were systematically investigated by using X-ray diffraction and pole-figure analysis. The Ni powder used in this study was 5 mum in size and 99.99% in purity. To find the optimum sintering temperature, tensile tests were performed for Ni rods sintered at various temperatures. The Ni rods sintered at 1000°C showed poor elongation and low fracture strength, while the Wi rods sintered above 1000°C revealed good mechanical properties. The higher elongation and fracture strength of the Ni rods sintered at higher temperatures than 1000°C are attributed to the full densification of the sintered rods. The sintered Ni rods were cold-rolled with 5% reduction to the final thickness of 100 mum and then annealed for development of rube texture in rolled Ni tapes. The annealed Ni tapes depicted strong cube texture with FWHM(full-width at half-maximum) of in-plane and out-of-plane in the range of 8° to 10°. The NiO deposited on the Ni tapes by MOCVD process showed good epitaxy with FWHM=10°, which indicates that the Ni tapes can be used as a substrate for YBCO coated conductors.

• Keywords: Ni tape;Texture;Cold-rolling;Recrystallization;FWHM;