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 (similar to 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.