Prediction of the microstructure evolution during the friction stir extrusion of a AA6061 aluminum alloy

Abstract. In recent years, the development of Friction Stir Extrusion (FSE) simulation models becomes crucial for gaining a deeper understanding of its underlying physics. Concurrently, there is a demand for precise control over the microstructure evolution of aluminum alloy extruded profiles, given its substantial impact on mechanical properties. Despite this, the relationship between process parameters and the evolution of grain structure remains insufficiently understood. In this context, a Lagrangian approach was established to simulate the FSE process, utilizing the commercial software DEFORM™ 3D. This research involved the investigation of the impact of various process parameters, such as rotational and descent tool speeds, on the occurrence of bonding phenomena, while considering both thermal and stress conditions. Furthermore, an innovative model originally developed for traditionally extruded components was implemented in a customized Fortran post-processing routine to investigate and predict the recrystallization behavior in the FSE of AA6061 aluminum alloy.