High Fe content in Al-Mg-Si wrought alloys facilitates excellent mechanical properties

Abstract

This study investigates the effect of a high volume fraction of Fe-rich intermetallic phases on microstructure evolution and mechanical properties in a cold rolled Al-Mg-Si wrought alloy. A conventional Al-Mg-Si alloy was modified by significantly increasing its Fe and Mn content, while the Si content was adjusted to keep the matrix composition comparable. Subsequent fast solidification and thermomechanical processing generated a dense distribution of fine intermetallic phases, which culminated in significant grain-refinement and uniform texture. The resulting alloy, with almost 10 vol-% Fe-rich intermetallic phase, features an unusually attractive combination of strength and ductility in addition to the substantially increased strain hardening typical of heterostructured materials, and can facilitate a higher usage of scrap input.