Deformation behavior of TC17 titanium alloy with basketweave microstructure during isothermal compression

Highlights: • The different GBS mechanisms result in different variation tendency on m. • The more intensive DRC at 0.1 s⁻¹ is related to the faster decline on n-value. • The Q decreases with an increase in strain and the Q-average is 374.3 kJ mol⁻¹. • The instability regions concentrate on the high strain rates range scale. • The η_max, always obtained at 1093 K and 0.0002 s⁻¹, arrives at ∼0.6. 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.