Abstract:To reveal the effects of solid solution temperatures (850 °C, 920 °C, 960 °C) on the microstructure and dynamic tensile mechanical properties of TC4 titanium alloy, XRD, SEM and EBSD methods were applied to analyze the characteristics of crystal structure, microstructure, and grain orientation of the material. The separated Hopkinson tension bar (SHTB) experimental device was used for dynamic tensile mechanical property testing of the material, and the Johnson-Cook (J-C) constitutive model was established. Finally, dynamic tensile fracture morphology analysis was performed. Results show that with the increase of solid solution temperature, the content of α/α′phase increases, the content of primary α phase decreases and the content of needle-like α′ phase increases, while the grain size decreases and the strength of selective orientation increases. TC4 titanium alloy exhibits a significant strain rate strengthening effect. With the increase of solid solution temperature, the material yield strength and Vickers hardness gradually increase, and the fracture elongation decreases. The dynamic tensile fracture exhibits ductile fracture characteristics, and with the increase of solution temperature, the plasticity of the material decreases. When the solid solution temperature is 960 ℃, the ductile fracture characteristics of the specimen are not significant. The conclusions of this paper can provide methods and data to support the mechanical property control and impact resistance design of TC4 titanium alloy.