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The strain rate sensitivity exponent, strain hardening exponent and apparent activation energy were calculated and the processing maps of isothermally compressed TC17 titanium alloy with basketweave microstructure were established. The influence of microstructure evolution and deformation mechanisms was investigated via the high-resolution electron backscatter diffraction and transmission electron microscope. The interaction effect among globularization of alpha platelets, alpha to beta phase transformation and deformation mechanisms resulted in the different variation in strain rate sensitivity exponent at the strain rates ranging from 0.0002 s −1 to 0.1 s −1 . The apparent activation energy decreased with an increase in strain and the average value was 374.3 ± 47.61 kJ mol −1 . The maximum efficiency of power dissipation at 1093 K and 0.0002 s −1 was obtained and respectively reached to 0.62, 0.65, 0.56 and 0.61 at the strains of 0.1, 0.2, 0.3 and 0.4.

The microstructure and texture evolution of isothermally compressed Ti-5Al-2Sn-2Zr-4Mo-4Cr with basketweave microstructure was examined via the high-resolution electron backscatter diffraction (EBSD) and transmission electron microscope (TEM). The rotational recrystallization (RRX) and the geometric dynamic recrystallization (GDRX) were the main recrystallization mechanisms of alpha phase. The typical continuous dynamic recrystallization (CDRX) was the main recrystallization mechanism of beta phase. Meanwhile, near the kinked shape alpha grains, the RRX of beta phase became an auxiliary mechanism to accommodate the high local stress. Besides, the dynamic recrystallization (DRX) in alpha phase played an important role in DRX of beta phase, which resulted in that the fragmental alpha grains were always accompanied with the DRX of beta phase in one macrozone. Moreover, with an intensive deformation, the “macrozone effect” played an important role in accommodating the whole arbitrary plastic strain.