Development of highly cube textured nickel superconductor substrate tapes by Accumulative Roll Bonding (ARB)

Development of cube texture ({001} < 100 >) has been investigated in pure Ni (99.97%) deformed to ultrahigh straining (epsilon = 6.4) by accumulative roll bonding and then annealed at different temperatures for use as coated superconductor substrate. The as accumulative roll bonding processed sheets reveal a typical pure metal or copper type homogeneous deformation texture. After annealing at different temperatures, strong cube texture formation is observed and a nearly 100% cube textured tape with almost twin-free microstructure is obtained after annealing at 800 degrees C for 1 h. The development of a sharp cube texture is accompanied by the development of a predominantly low angle boundary network. The very sharp cube texture formation in this material appears appears to be due to the oriented nucleation of cube grains at early stages of recrystallization and selective growth of these grains with progressing recrystallization. The results obtained indicate that accumulative roll bonding could be a very attractive route for fabricating highly cube textured superconductor substrate tapes from Ni.