Correlation between Flow Behavior and Microstructure Evolution during α/β Deformation of TA19 Titanium Alloy

The flow behavior during alpha/beta deformation of TA19 titanium alloy is investigated by microstructure examination using an optical microscope (OM), a scanning electron microscope (SEM), and a transmission electron microscope (TEM). The results show that the strain rate sensitivity exponent (m) and strain hardening exponent (n) values increase with the increasing of deformation temperature. The microstructure examination reveals that the increasing of beta phase content, grain refinement, DRV, and DRX benefit the deformation stability to make the m-value increase. The DRV and DRX promote the dislocation annihilation to make the n-value decrease. Meanwhile, the DRX occurring in both primary alpha and beta phases makes the Q-value in 900-980 degrees C region much higher than that in 820-860 degrees C region