Texture memory and variant selection during phase transformation of a zirconium alloy

The texture evolution of cold-rolled Zircaloy-2 sheets during the α → β → α phase transformation was characterized in situ using high-energy synchrotron X-ray diffraction. It was found that the strong rolling texture is initially modified during heating, evidencing recrystallization, after which it is weakened by a complete phase transformation. Hardly any variant selection was observed during α → β phase transformation. When the material was rapidly cooled back from above the β-transus, the α texture exhibited moderated variant selection. In a study of the effect of maximum heating temperature on the inherited α texture, it was found that incomplete transformations, even with peak temperatures nearing the β-transus, resulted in a perfect texture memory in spite of dramatic morphological changes in the microstructure.