Ti–6Al–4V alloy (Ti64) with different microstructures was first preshocked at ~6–13 GPa and then compression reloaded at 4×103s-1 to investigate the effect of microstructure and shock prestrain on the dynamic mechanical behavior of this alloy. The strengthening effect caused by shock prestrain is weaker than that introduced by the uniaxial stress compression during dynamic reloading process regardless of microstructure type and impact stress amplitude. However, the shock-induced enhancement ratio is higher in Ti64 having bimodal microstructures or the lamellar microstructure with wide α-platelets. These mechanical behaviors exhibited by postshock materials are closely related to the shock-induced microstructure evolution. Dislocations more tend to nucleate and interact in large-sized α phases such as equiaxed primary α and wide α-platelets. The generation of high-density micro-defects during the propagation of shock waves results in the improvement of strength but degradation of ductility of Ti64 during dynamic reloading process.
