Modeling of flow behavior of Ti-6Al-4V alloy at elevated temperatures

Titanium alloy grade Ti-6Al-4V has been widely used for many applications such as aircraft structural component, machine parts and especially parts for medical equipment. To better understand the deformation behavior and microstructure evolution of the material under the hot working process is significant for achieving desired dimension and final mechanical properties of a product. In this study, stress-strain responses of the Ti-6Al-4V alloy were investigated using compression tests at different elevated temperatures and strain rates. The determined flow behaviors of the alloy were subsequently calculated according to the constitutive models based on the hyperbolic sine equation, the Cingara equation, and the Shafiei and Ebrahimi equation. Influences of both work hardening and dynamic recrystallization on the hot deformation behavior of the material were described. Then, the predicted flow curves were compared with experimental results and obtained discrepancies were characterized. Accurate modeling of flow curves can considerably assist in design of the forming process.