Development of Textured Ni Substrates for Coated Conductor Prepared by Powder Metallurgy and Plasma Arc Melting Method

Abstract

We fabricated the textured Ni substrate and evaluated the effects of processing variables on microstructural evolution and texture transformation. Ni-rods as an initial specimen were prepared by two different methods, i.e., powder metallurgy (P/M) and plasma arc melting (PAM). To evaluate the effect of two preparation methods, the initial specimens were prepared to be of same size and experienced by same rolling conditions. The texture of the substrate was characterized by pole-figure and surface condition was evaluated by atomic force microscopy. It was observed that the texture of substrate made by P/M did not significantly varied with annealing temperature of 800 /spl sim/ 1200/spl deg/C and the full-width at half-maximums (FWHM) of both in-plane and out-of-plane were 9/spl deg/ /spl sim/ 10/spl deg/. On the other hand, the texture of substrate made by PAM was more dependent on the annealing temperature and the FWHM of in-plane texture was 9/spl deg/ /spl sim/ 13/spl deg/ at the temperature range. In addition, twin texture, (221), was formed as the temperature increased further. OM micrographs showed that the grain size of substrate made byP/M was smaller than that made by PAM and this difference was correlated to the microstructure of initial specimens.