Abstract:In this paper, the effect of deformation temperature on the evolution of microstructure and properties of TC4 alloy has been studied by a constant-strain rate tensile test at high temperature. The results show that both the peak stress and required strain of peak stress decrease with increasing temperature in a α+β dual-phase field. The deformed microstructure exhibits a strong temperature-dependent evolution with temperature. Deformation leads to an accelarated recrystallization and refinement of primary α phase at a lower temperature of α+β phase field (below 900 °C), whereas results in a significant spheroidization of secondary α phase at a higher temperature (above 900 °C). Additionally, deformation also affects the nucleation and growth process of β→α transformation, resulting in a larger amount of secondary α phase. With increasing deformation temperature, the volume fraction of α phase firstly decreases and then increases, which shows a good consistence with hardness. However, the corrosion resistance displays a reverse evolution with the amount of α phase. TC4 alloy exhibits a lowest volume fraction of α phase of 57% at a deformation temperature of 900 °C, which corresponds to a lowest hardness and a best corrosion resistance in a NaCl solution.