M Seyed Salehi - Department of materials science and engineering, K. N. Toosi University of Technology, Tehran, Iran
N Anjabin - Department of materials science and engineering, School of engineering, Shiraz University, Shiraz, Iran

In the present study, the mechanical behavior of AA5052 aluminum alloy during cold- working and subsequent isothermal annealing in a temperature range of 225-300 ◦C was investigated, using the uniaxial tensile test data. It is found that by increasing the annealing time and temperature, the material yield strength is decreased. The microstructural investigations of the annealed samples show that the grains are elongated and there is no evidence of recrystallization. Hence, recovery is the main restoration phenomenon during the annealing treatment. The work hardening behavior of the alloy during cold working is modeled using a dislocation density based modeling approach and the softening behavior of the deformed samples during subsequent annealing is modeled by applying a kinetics equation relating the yield strength to the annealing parameters. The kinetics equation is a nonlinear differential equation and it is solved numerically by employing Runge-Kutta-Fehlberg (RKF) integration scheme which is coupled with Gauss-Newton nonlinear optimization technique to obtain the material constants of the model. The numerical results are validated using the experimental flow data.

Kinetics of static recovery, AA5052 aluminum alloy, Cold working, Isothermal annealing, Nonlinear regression