Effect of heat treatment and Cu addition on the mechanical, electrochemical, and precipitation behavior of Al–Mg–Si alloys

This study systematically explores the dual role of Cu addition and aging treatments in shaping the microstructure, mechanical properties, and corrosion behavior of Al–Mg–Si alloys. The addition of Cu enhances mechanical strength by refining precipitates and introducing Cu-containing phases, such as Q′ and L, while initially increasing the susceptibility to intergranular corrosion (IGC) due to Cu segregation at grain boundaries. Advanced characterization techniques, including transmission electron microscopy (TEM) and small-angle neutron scattering (SANS), reveal the evolution of precipitate size, distribution, and volume fraction under varying aging conditions. Notably, prolonged aging mitigates IGC by redistributing Cu, thus improving corrosion resistance without significant loss in strength. This work bridges the gap between microstructural evolution and performance optimization, providing insights into balancing strength and corrosion resistance in Cu-modified Al–Mg–Si alloys for industrial applications.