Microstructure Evolution and FEM Prediction on AA6XXX Alloys

The microstructure evolution during the extrusion process of AA6XXX aluminum alloys is getting a significant interest from extruders and researchers because of the effect of the grain structure on the extruded component properties. Several process and material parameters such as chemical composition, homogenization, temperature evolution, extrusion speed, geometries and quenching have a direct impact on the final grain size of extruded profiles. Because there are so many affecting elements, it is extremely challenging to forecast the microstructure evolution and, as a result, research activities are still required to understand and control the aluminum alloy recrystallization behaviour. In this work, a methodology for the microstructural characterization of AA6XXX aluminum alloys is proposed. The methodology involves the experimental investigation of the profile grain evolution during the extrusion process, the development of a AA6XXX recrystallization model optimized to describe the AA6063 recrystallization behaviour and the simulation by means of finite element method of the final microstructure of the extruded profile.