Physical modelling of $\rm Ti$–$6\rm Al$–$4\rm V$ alloy above $\beta$ transus at high temperatures $(1010$–$1150^{\circ}$C$)$ and high strain rates using Garofalo and Hensel–Spittel laws

A phenomenological model based on the combination of the Garofalo and Hensel–Spittel equations is used to obtain a quite accurate description of the flow curves of $\rm Ti$–$6\rm Al$–$4\rm V$ alloy for processing temperatures between $1010$ and $1150^{\circ}$C and strain rates of $100{,}~50{,}~10{,}~1{,}~0.1{,}~0.001$ s$^{-1}$. The hot deformation is achieved by dynamic recovery in the $\beta$ phase by subgrain formation. The activation energy of the dynamic recovery $Q_{HW}$ is determined as $202$ kJ/mol and the stress exponent $n$ is $3.92$. The analysis of the experimental data by constitutive model shows an excellent result of describing the flow curves.