Evolution of deformation and recrystallization textures in high-purity Ni and the Ni-5 at. pct W alloy

An attempt has been made to study the evolution of texture in high-purity Ni and Ni-5 at. pct W alloy prepared by the powder metallurgy route followed by heavy cold rolling (∼95 pct deformation) and recrystallization. The deformation textures of the two materials are of typical pure metal or Cu-type texture. Cube-oriented ({001} {100}) regions are present in the deformed state as long thin bands, elongated in the rolling direction (RD). These bands are characterized by a high orientation gradient inside, which is a result of the rotation of the cube-oriented cells around the RD toward the RD-rotated cube ({013} {100}). Low-temperature annealing produces a weak cube texture along with the {013} {100} component, with the latter being much stronger in high-purity Ni than in the Ni-W alloy. At higher temperatures, the cube texture is strengthened considerably in the Ni-W alloy; however, the cube volume fraction in high-purity Ni is significantly lower because of the retention of the {013} {100} component. The difference in the relative strengths of the cube, and the {013} {100} components in the two materials is evident from the beginning of recrystallization in which more {013} {100} -oriented grains than near cube grains form in high-purity Ni. The preferential nucleation of the near cube and the {013} {100} grains in these materials seems to be a result of the high orientation gradients associated with the cube bands that offer a favorable environment for early nucleation

Evolution of microstructure and texture during cold rolling and annealing of a highly cube-textured ({001}(100)) polycrystalline nickel sheet

The evolution of microstructure and texture is studied during the heavy cold rolling and annealing of a highly cube-textured ({001}(100)) polycrystalline nickel sheet. Near and intermediate cube grains (≤5 deg and 5 deg to 10 deg misorientation, respectively, with exact cube orientation) are more unstable up to 60 pct reduction compared with the far cube grains (10 deg to 15 deg misorientation), and they rotate away to a rolling direction (RD)-rotated cube orientation ({013}(100); denoted by C RD). In contrast, beyond 60 pct reduction, near and intermediate cube grains are more stable than far cube grains, which results in an overall increase in the stability of cube orientation. After 90 pct cold rolling, several cube bands adjacent to or surrounded by C RD bands and separated by low-angle grain boundaries (LAGBs) over large part of their lengths are observed. After annealing of the 90 pct rolled material, no cube texture formation is observed, which is attributed to the delayed nucleation of cube grains owing to the unfavorable structure and local misorientation environment surrounding cube band