TEXTURE CHANGES IN ALPHA-ZIRCONIUM ON TRANSVERSE ROLLING

Research on texture formation in metals involves not only establishing the final stable textures but also defining the trends in grain reorientation, which are determined by the plastic-strain mechanisms and can be used in researching the latter. The final rolling textures in zirconium-base alloys have been described repeatedly, but the formation mechanisms have not been fully elucidated. Existing explanations for stable textures in hexagonal metals (titanium and zirconium) are based on results for coarse-grained specimens after comparatively slight strain. One finds preferential twinning in annealed zirconium in the initial stages of stretching or rolling, which has served as basis for most studies on textures in zirconium, where twinning is considered as one of the basic mechanisms producing the final stable orientation. Here no allowance has been made for the fact that the twinning activation probability is certainly dependent not only on the grain orientation but also on the fragmentation, which increases with the strain. It is therefore desirable to identify the texture trends in alpha -zirconium on transverse rolling for plates with various structural states.