Constitutive modeling of flow behavior of precipitation-hardened AA7022-T6 aluminum alloy at elevated temperature
(School of Mechanical Engineering, Arak University of Technology, Arak, Iran)
Abstract: The thermomechanical behavior of precipitation-hardened aluminum alloy AA7022-T6 was studied using isothermal compression at temperatures of 623-773 K and strain rates of 0.01-1 s-1. The experimental results indicated that dynamic recrystallization (DRX) is a predominant hot deformation mechanism, especially at elevated temperatures and low strain rates. The modified Johnson-Cook (J-C) and the strain compensated Arrhenius-type models were developed to predict the hot flow behavior under different deformation conditions. The correlation coefficients of modified J-C model and the strain compensated Arrhenius-type models were 0.9914 and 0.9972, respectively, their average relative errors (ARE) were 6.074% and 4.465%, respectively, and their root mean square errors (RMSE) were 10.611 and 1.665 MPa, respectively, indicating that the strain compensated Arrhenius-type model can predict the hot flow stress of AA7022-T6 aluminum alloy with an appropriate accuracy.
Key words: flow behavior; constitutive models; Arrhenius model; dynamic recrystallization; AA7022-T6 aluminum alloy