Effect of forging deformation on the formation of {10–12}<10–1–1> twins and their influence on the tensile properties of TC4

This study investigates the deformation behavior and microstructural evolution of TC4 titanium alloy subjected to 20–80 % forging deformation during thermomechanical processing at 930 °C. Tensile behavior was evaluated through experiments and the crystal plasticity finite element method (CPFEM), and microstructural analysis was carried out via EBSD. Results revealed significant grain refinement at deformation levels above 60 %, attributed to the enhanced activation of {10–12}<10–1–1> twinning, which led to the formation of ultrafine grains and reduced average grain size. The study further demonstrated that twin variant selection depends on forging deformation, with Variant 6 dominating at high deformation and promoting transgranular twin networks. Moreover, the presence and type of twins significantly influenced slip systems activation, resulting in more complex deformation behavior in twinned grains compared to non-twinned ones, where basal slip consistently dominated. Grain orientation distribution was found to critically govern the activation sequence of deformation mechanisms. Orientation randomization at the highest deformation level (80 %) increased heterogeneity in slip system activation, thereby promoting deformation complexity through auxiliary slip modes. These findings deepen the understanding of microstructural evolution and deformation mechanisms in TC4 under forging and uniaxial tension, supported by experiments and CPFEM.