Localized forging strain governs creep anisotropy via texture-controlled diffusion in near-α TA32 alloy

Forging-induced crystallographic texture critically governs the creep anisotropy of near-α titanium alloys, directly compromising the reliability of high-temperature structural components. Here, the interrelationships among localized forging strain, microstructure, texture, and creep anisotropy in a TA32 alloy are systematically investigated through a multi-scale approach integrating experimental characterization with first-principles calculations. Increasing forging strain progressively refines the duplex microstructure and strengthens a pronounced ⟨11-20⟩//ST texture inherited from the parent β phase. While microstructural refinement enhances room-temperature tensile strength, the intensified texture introduces pronounced creep anisotropy at 550 °C, with the longitudinal direction exhibiting markedly superior creep resistance over the short-transverse direction. First-principles calculations reveal that this anisotropy originates from the intrinsic directional dependence of vacancy-mediated atomic diffusion: the ⟨11-20⟩ direction presents the lowest migration energy barrier, and its alignment with the ST loading axis accelerates dislocation climb, thereby reducing creep resistance. Consequently, the medium-strain region (0.75–0.90) defines an optimal forging processing window balancing strength, microstructural stability, and creep resistance.