Abstract: Electron backscatter diffraction (EBSD) was used to characterize the grain size, recrystallization and texture of cold-rolled and annealed TA5 titanium alloy plates, the effects of deformation non-uniformity on recrystallization behavior and texture evolution were discussed. The results show that <0002>//TD-oriented grains are more prone to deforming than <0002>//ND-oriented grains, combined with the limited-slip system of hcp structure, which jointly determine the non-uniformity of cold-rolled deformation of TA5 alloy plates. In the early stage of annealing, the recrystallization rapidly nucleates in the high-stored-energy regions, and the greater the deformation, the more nucleation number, and the smaller the grain size of the sample after recrystallization. The recrystallized grains rapidly complete nucleation through the "oriented nucleation" mechanism in high-stored-energy regions during the early stage of annealing and then grow, including a small amount of residual severely deformed <0002>//TD-oriented grains. At the same time, the recrystallized grains nucleate slowly through the "strain-induced boundary migration" mechanism in the regions with low-stored-energy during the entire recrystallization process. These two mechanisms work together to weaken the texture of the annealed plate, but the cold-rolled state basal texture is still dominated. The hardness curve can well reflect the degree of recrystallization, however, the hardness values of different test surfaces affected by the texture are significantly different. The larger the angle between the loading axis and the crystal c axis, the smaller the hardness value.

Key words: TA5 titanium alloy, deformation heterogeneity, recrystallization, texture, hardness