Role of microstructure in hot deformation behavior of β high-strength titanium alloy Ti-3.5Al-5Mo-6V-3Cr-2Sn-0.5Fe under constant load

The effect of microstructure on hot deformation behavior of high-strength β titanium alloy Ti-3.5Al-5Mo-6V-3Cr-2Sn-0.5Fe under constant load was studied. Two kinds of heat treatment were carried out. The hot deformation experiments were carried out. The microstructure with ultrafine grain structure was obtained after deformation. The regions with different strain were studied respectively. The HT2 alloy had the best hot deformation performance, and its deformation mechanism was mainly dynamic recovery and discontinuous dynamic recrystallization in difficult deformation regions and the continuous dynamic recrystallization and α phase spheroidization in large deformation regions. The original microstructure will significantly affect the deformation behavior, including the microstructure morphology after deformation, recrystallization behavior. The α phases with different morphologies also had different effects on the deformation, including the fracture of α_GB phase, uneven precipitation of α_s phase, spheroidization of α_s phase, and kinking of α_p phase.