Effect of processing variables on cube texture formation in powder metallurgically prepared Ni and Ni-W alloy tapes for use as substrates for coated conductor applications

摘要

Development of textures have been studied in powder metallurgically prepared pure Ni and Ni-5 at.% W alloy after heavy cold rolling (～95% reduction in thickness) and annealing for use as substrates for coated superconductor applications. The cold rolling textures of the two materials do not show any significant difference. However, Ni-5 at.% W alloy is found to develop a much sharper cube texture after annealing which indicate the beneficial role of W in increasing the cube volume fraction in Ni. W increases the volume fraction of the cube component by decreasing the volume fraction of the rolling direction (RD)-rotated cube grains. Partial recrystallization studies clearly indicate that in contrast to pure Ni sharp cube oriented grains form in Ni-5 at.% W alloy right from the beginning of recrystallization. A near 100% cube texture is obtained in Ni-5 at.% W alloy by an optimized two stage rolling (TSR) procedure followed by annealing at 1350℃.