ABSTRACT Increasing the usage of recycled aluminum (Al) is an efficient way to maintain a low‐carbon supply‐chain for modern automobile companies, where the major challenge is the mitigation of the negative effect of tramp element, such as Fe. This paper aims at the application scenario of recycled Al in automobile profiles, presenting a thorough investigation on the morphology, size, and fraction of Fe‐contained intermetallic compounds (IMCs) in Al‐Mg‐Si alloys with excess Fe contents. Comprehensive understandings were established across the entire process chain, leading to a two‐pronged adjustment strategy. First, the Mn/Fe ratio and Mn content were found to govern the morphology and fraction of IMCs, while the solidification cooling rate dictates their size and distribution. Notably, we revealed that the solidification cooling rate exerts a decisive, penetrative influence that persists through homogenization and deformation processes. This combined effect yields fine, short‐rod IMCs in the as‐cast microstructure, which subsequently undergo spheroidization and fragmentation during homogenization and deformation, minimizing the harmful impact of Fe‐contained IMCs. Second, the Mg/Si ratio and aging parameters enable direct control over Mg 2 Si precipitation, optimizing the strength‐ductility balance. Further, plant‐scale trials successfully produced Al–Mg–Si extrusions from recycled Al, which fully meet the mechanical property requirements for automotive structural components.
Ma et al. (Sun,) studied this question.