Study on hot deformation behavior and microstructure evolution mechanism of TA10 titanium alloy at high temperature
摘要
To explore the rheological behavior and microstructure evolution of TA10 titanium alloy under high-temperature deformation, the isothermal hot compression experiments were carried out at 800–1050 °C and strain rate of 0.01–5 s−1. Based on the relationship between flow stress and deformation conditions, the apparent activation energy of TA10 titanium alloy was calculated by the Arrhenius equation to be 339.46 kJ/mol. The effects of deformation temperature and strain rate on the flow stress were studied by analyzing the true stress–strain curve, and the hot-processing map was constructed based on the dynamic material model to evaluate the processing stability. The grain orientation, local misorientation and grain boundary characteristics were characterized by the Electron Backscatter Diffraction (EBSD) technique, and the dislocation evolution, dynamic recovery and dynamic recrystallization behavior were analyzed. The results show that the flow stress decreases with the increase in temperature and increases with the increase in strain rate. Dynamic recovery is the main feature under low-temperature or high-strain rate conditions, while the degree of dynamic recrystallization is higher under high-temperature and low-strain rate conditions. The hot-processing map shows that the medium–high-temperature and low-strain rate are the ideal processing windows. This work has certain reference value for the design and optimization of thermal processing parameters of TA10 titanium alloy.