Thermal effects during tensile deformation of Ti-6Al-4V at different strain rates

An in-depth analysis of the effect of heat generated by plastic work on the observed tensile behaviour of Ti­6Al­4V at different strain rates is presented. Special emphasis is put on the transition from isothermal to adiabatic conditions and how this transition is affected by several process parameters such as material properties, environmental conditions and sample geometry. Experiments are performed in isothermal conditions at moderate temperatures, from −10 to 70 °C, as well as at strain rates from quasi-static speeds to more than 1000 s−1 using a split Hopkinson tensile bar setup. This experimental data is used in conjunction with numerical simulations to determine the evolution of temperature during the experiments and the temperature and strain rate sensitivity of the material, as well as the Taylor–Quinney coefficient. Finally, a full model of the material behaviour is presented and used to define clear limits for adiabatic and isothermal conditions