Effect of material characterization via torsion tests on the accuracy of FEM simulations in the extrusion process

The Finite Elment Method codes are nowadays potent and useful tools for advancing the design and optimization of metal forming processes. This is particularly evident in sectors such as aluminum extrusion, where FEM contributes to both process enhancement and tool development, mitigating the high costs and time demands of experimental trials. However, accurate and reliable simulations require precise material flow stress modeling. In this context, the hot torsion test is considered the most suitable for material characterization as it allows for achieving the high strain levels typical of the extrusion process while maintaining stable temperature and strain rate conditions during testing. This work presents the characterization via torsion tests of four distinct alloys, all classified within the AA6082 series, obtained from different casting batches. The resulting data were subsequently employed as input for numerical simulations of an industrial extrusion process and compared with experimental results to assess the impact of flow stress modeling on the accuracy and reliability of the simulations.