The cold-rolling and β-recrystallization textures of zircaloy 2

A study has been made of the cold-rolling and β-recrystallization textures of Zircaloy-2. From a hot-rolling texture consisting mainly of a distribution between {24}, {103} and (0001) components, with a minor {3 1} component, a strong (0001) rolling texture is gradually developed. Between 71.5% and 78% reduction, the intensity of (0001) increases quite markedly, and between 86.5% and 90% reduction there is a slight decrease. Development of the rolling texture is accompanied by a gradual change in the corresponding β-annealing texture, i.e. the initial sheet recrystallizes to a very strong {31} texture; after 39.5% reduction other components appear in the annealing texture between (0001) and {103}, and the intensity of {31} decreases. With increasing reduction this transition continues, until, after 90% the β-recrystallization texture may be described as (0001) + {103} + {101}, with a scatter between these orientations and between {101} and {100}. The initial development of the rolling texture is attributed to interaction of slip on {100}, {101} and (0001) planes with twinning taking place on {102}, {111} and {112}. The rapid rotation towards (0001) between 71.5% and 78% reduction is considered to be due to extensive cross-slip between {101} planes, while the later movement of peak intensity away from (0001) is attributed to re-activation of latent slip systems. The β-recrystallization textures are consistent with an orientation-selective growth mechanism in the β phase, corresponding to a rotation of approximately 45° about a 〈111〉 axis.