Creep anisotropy characteristics and microstructural crystallography of marine engineering titanium alloy Ti6321 plate at room temperature

The anisotropy of the mechanical properties of high-performance titanium-alloy plates has always been a key challenge in the fabrication of alloy plates and the application of components in service. In this work, the room-temperature creep behavior and microstructural crystallography of Ti6321 alloy plates along the rolling direction (RD), 45°, and transverse direction (TD) have been thoroughly investigated and discussed. The study demonstrates that the plates exhibit significantly different room-temperature creep characteristics along the three sampling directions. Among them, the creep strain along the 45° direction was the largest, whereas the creep strain along the TD was the smallest. Such anisotropic deformation was associated with the global Schmid factor variation caused by the T-type microtexture. Both the basal and prismatic slips occur easily along 45°, whereas it was hard to activate along the TD. In addition, the basal and prismatic slips were the main contributors to creep deformation, which also showed strong crystallographic orientation dependence. Among them, the basal slip was found to be more easily activated than prismatic slip, especially in the high Schmid factor range. The study also discusses the potential influence of elastic anisotropy on the activation of basal slip.