Influence of Initial Textures on Microstructure and Mechanical Properties of Commercially Pure TA2 Titanium Sheet Pre-Strained by Cryorolling

Titanium alloys are one of the most important structural materials for the aerospace applications, which bring active study on microstructural and mechanical optimization of the alloys. In the present study, commercial TA2 titanium sheets with different initial textures were rolled to a strain of 4% at liquid nitrogen temperature. Microstructures of the rolled sheets were characterized using a scanning electron microscope equipped with an EBSD detector and their mechanical properties were tested through quasi-static uniaxial tension tests at room temperature. The influence of the initial texture on the microstructure and mechanical performance of the cryorolled sheet were discussed. Twinning is found to occur in the TA2 sheets after rolling even at a small strain. Initial texture is an important factor affecting both numbers and types of the twins. {11–22} contraction twinning is always the dominating type of twins for all three sheets having different initial textures. A lot of {11–22} and {11–24} twins can be found in the sheets with the initial texture of C-axes//ND, while the sheet with an initial texture of C-axes away from the ND contains few twins, with a high density of dislocations developed instead. Along with contraction twinning, many {10–12} and {11–21} twins are detected in the sheet with the initial texture of C-axes⊥ND. The cryorolled sheet having the densest twins shows the best mechanical properties, indicating a beneficial effect of a small pre-strain.