Evolution of microstructure and texture during cold rolling and high-temperature annealing in Ni–5 at% W substrate for coated conductor

Abstract

The evolution of microstructure and texture at four strain levels was investigated in Ni–5 at% W alloy by means of electron backscatter diffraction (EBSD) technique. The deformation microstructure evolves gradually from microbands (MBs) to typical lamellar structures with strain increasing in cold-rolled materials, while only lamellar structures in heavily cold-rolled materials. Subsequently, quantitative analysis of microstructure and texture was performed. It indicates that the texture is a typical pure metal deformation texture, but a few cube and rolling direction (RD)-rotated cube orientations also can be observed in the deformed samples. The use of high-temperature annealing enables an area fraction of cube orientation > 95% to be obtained for high strained substrate. In addition, it is worth noting that the point-to-point misorientation inside the band with various orientations is found to keep quite low. But the point-to-origin misorientation over the same distance is dependent on strain and orientation type in the band. The cube-oriented regions were characterized by a high accumulated orientation gradient, close to 28°, compared to the non-cube-oriented regions. This means that the accumulated orientation gradient only occurs in the cube band with the reduction of 98%, which partly explains the formation of strong cube texture after high-temperature annealing.