Analytical modeling of hot behavior of Ti-6Al-4V alloy at large strain

Abstract

Hot deformation behavior of the Ti-6Al-4V alloy is studied through hot torsion tests. Cylindrical samples are twisted at different strain rates and temperatures in the β phase domain. The recorded torque vs twisting angle data are converted to strain vs stress data using the appropriate methods. All the flow curves obtained are characteristic of continuous dynamic recrystallization. The flow stresses exhibit rapid growth to reach a single maximum followed by a decrease and a steady-state regime. The influence of strain rate and temperature is taken into account. An analytical model is proposed, which gives accurate flow curves for the Ti-6Al-4V alloy for processing temperatures between 1000 °C and 1100 °C and strain rates between 0.01/s and 1/s. The model is validated by further experimental tests. Keywords: Large strain, Hot behavior, Ti-6Al-4V alloy, Flow stress, Analytical behavior law, Torsion test