As aluminum 3104 alloy is from high interest in many different industries, the study investigated the effect of heat treatment parameters on the grain size evolution. Therefore, plain foil in as-rolled state was subjected to two different annealing processes. For the first annealing process, the foil was exposed to different temperatures at a constant annealing time of 24 hours, while in the second process the change in microstructure over time at a constant temperature of 250°C was investigated. 

The metallographic preparation of thin aluminum foils is carried out by a plane grinding step using SiC paper and polishing using diamond pastes and OPS suspension. The grinding times for cross-sections are set long in order to remove deformation zones. Grinding times for surface sections of rolled foils are deliberately kept short to prevent cracks during preparation. The sections are etched using the Barker method at low voltage for 60s and viewed using polarized light. The microstructure analysis of the first process revealed a fully recrystallized state at 250°C with a grain size of 16µm in both rolling and transversal direction.