Recrystallization and Cube Texture Formation of Ni9W Alloy Substrate for Coated Conductors

Deformation and recrystallization textures of Ni9W alloy tapes deformed by cold rolling with and without intermediate annealing were investigated by XRD, which indicated the texture transition between rolling and recrystallization textures during annealing. Furthermore, the microstructure and cube texture of Ni9W alloy substrates were studied by electron back scattered diffraction (EBSD). The results show that there are more fractions of S and Copper orientations as well as less Brass orientations in the rolling texture of Ni9W alloy tapes cold rolled with intermediate annealing, resulting in a mixed rolling texture between Brass type and Copper type. The fractions of rolling texture for both Ni9W tapes are increased during a long-term recovery, and then decreased significantly in recrystallization process. But, the fraction of cube orientation does not increase obviously, while a large amount of random orientation forms during recrystallization. The recrystallization of the Ni9W alloy is continuous, which is one of the main reasons for rough cube texture formation in Ni9W substrates. Though there is no strong cube texture formed after primary recrystallization for the Ni9W taps cold rolled with intermediate annealing, the fraction of cube orientation can be enhanced during grain growth with high temperature annealing. At last, strong cube texture fraction of 84.5% (< 15 degrees) is obtained by two-step annealing for the Ni9W substrates deformed by cold rolling with intermediate annealing.