Orientation dependent behavior of tensile-creep deformation of hot rolled Ti65 titanium alloy sheet

The mill products like sheet always have one or more severe textures inevitably, and its effect on mechanical properties is not a negligible issue. The orientation dependent tensile-creep behavior induced by rolling texture of Ti65 titanium alloy sheet has been systematically investigated at 650 degrees C. There are some anisotropic characteristics between TD and RD of Ti65 sheet. The UTS and TYS of TD are higher than RD at 650 degrees C. Besides, the creep endurance time of TD (172.6-174.5 h) is about three times longer than RD (55.6-65.1 h) at 650 degrees C and 240 MPa. Moreover, the grains are inclined to form Texture III (1 2 1 6)[1 2 11] and (01 1 3)[1 2 11] after creep along with TD, but to form Texture I (1 2 1 0)[10 1 0] after creep along with RD. Finally, the crack initiation site is different during creep in TD and RD. The reason for anisotropic properties of tensile and creep has been summarized in two aspects: (i) the change of the SFs (Schmid factors) value between TD and RD; (ii) the difference of creep mechanism between TD (grain boundary sliding) and RD (dislocation slip). Anisotropy of Ti65 sheet should be fully considered to increase structural efficiency in the engineering design and application. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

The study on Ti65 titanium alloy sheet revealed anisotropic properties in terms of tensile strength, yield strength, and creep endurance between transverse direction (TD) and rolling direction (RD). The orientation of grains and crack initiation sites also showed distinct differences during the creep process. Factors contributing to this anisotropy include changes in Schmid factors values and differences in creep mechanisms between TD (grain boundary sliding) and RD (dislocation slip). It is important to fully consider the anisotropy of Ti65 sheet to enhance structural efficiency in engineering design and application.