Modeling of the plastic characteristics of AA6082 for the friction stir welding process

Focus of this paper is to model the plastic forming behavior of AA6082, in order to develop the numerical FE analysis of the friction stir welding processes and the simulation of subsequent forming processes. During the friction stir welding process, the temperatures reached can range up to 500 °C and have a fundamental role for the correct performance of the process, so the material data has to show a temperature dependency. Because of the tool rotation a strain rate sensitivity of the material has to be respected as well. In this context, the general material characteristics of AA6082 were first identified for different stress states. For the uniaxial state the standard PuD-Al used in the automotive industry was applied, for the shear state the ASTM B831- 05 was used and for biaxial states the ISO 16842 was exploited. To characterize the plastic flow behavior of the AA6082 at elevated temperatures, tensile tests were performed according to DIN EN ISO 6892-2 from 25 °C to 500 °C with a strain rate from 0.1 s-1 up to 6.5 s-1.