A modified Arrhenius constitutive model of 2219-O aluminum alloy based on hot compression with simulation verification

Abstract

A precise constitutive equation is essential to accurately describe the flow behavior of aluminum alloy in numerical simulation of hot-forming process. In this study, the hot compression tests were conducted by Gleeble-3500 thermal-mechanical simulator, and flow stress data of 2219-O aluminum alloy at temperature of 523–763 K and strain rate of 0.01–25 s−1 were obtained. Based on the corrections of the original flow stresses data with the consideration of interfacial friction and specimen temperature variation, Arrhenius constitutive models with four different forms were established and their prediction accuracy was evaluated. Although the strain compensated Arrhenius model can achieve the highest accuracy, its expression is very complex. Hence, a newly modified constitutive model of 2219-O Al alloy with a simpler function structure was proposed to accurately predict the evolution behavior of flow stress with strain effect included. In order to compare the calculation of the founded model with the other models, a finite element model of the hot compression process by integrating with the aforementioned equations was established. The simulated flow stress evolution based on both newly modified model and strain compensated model showed an excellent agreement with the experimental data. The newly founded constitutive model of 2219-O Al alloy show its advantages in applications because of its structural simplicity.