Constitutive Analysis to Predict High-Temperature Flow Stress in 2099 Al-Li Alloy

Constitutive analysis for hot working of 2099 aluminum-lithium (Al-Li) alloy was carried out employing friction and temperature corrected flow curves from isothermal hot compression test, in a wide range of temperatures 300∼500 °C, at strain rates 0.001∼10 s−1 and strains 0.1∼0.7. The effects of temperature and strain rate on hot deformation behavior were represented in terms of a hyperbolic sine type Zener-Holloman (Z) parameter equation. The influence of strain was incorporated in the constitutive analysis by considering the effect of strain on material constants. Consequently, a model to predict the high-temperature flow behavior of 2099 Al-Li alloy has been established. The true stress-true strain curves predicted by the developed model are in good agreement with the experiment results throughout the deformation conditions except at 300 °C in 10 s−1.