Using response surface methodology to optimize the strain aging response of AA5052

In the present work, in a new attempt, stabilizing of AA5052 by strain aging rather than by conventional aging (H3 temper) was studied. The process was then modeled using response surface methodology (RSM) based on central composite design (CCD). According to the CCD, various stabilization treatments were carried out under different strain aging/baking conditions. Two models were developed to predict the influence of strain aging parameters on the final yield stress (FYS) and baking response of AA5052. These models were then used to predict the optimal combination of baking parameters in order to attain the best mechanical properties after the stabilization of AA5052 by strain aging. The contour plots were also used to study the interaction significance of process variables. To verify the developed models, the tests were carried out according to the values predicted by the models. The accuracy of predicted results was analyzed using the analysis of variance (ANOVA) method. The optimum values predicted by the RSM and CCD were 9% staining followed by aging at 285 °C for 35 min that resulted in a hardening increment of about 87 MPa. The multiple correlation coefficient (R2) of the regression models was about 0.98 confirming the excellent accuracy of developed models.