The Role of Cu-Based Intermetallic on the Direct Growth of a ZnAl LDH Film on AA2024

The direct ZnAl layered double hydroxide growth on AA2024 is a fast-occurring reaction, yet characterized by an inhomogeneous film thickness. It has been shown that at the periphery of Cu-rich intermetallic, flakes tend to be larger and denser. A combination in situ ex measurements were used monitor changes grown regions intermetallics. Immediately after immersion, activation intermetallic phases observed due dealloying process with almost immediate growth. Dealloying followed trenching adjacent Al matrix leading excessive production large dense intermetallic. However, scanning electron microscopy cross-section images revealed leads defects area surrounding This could weaken corrosion resistance performance conversion coating lead adhesion failure consecutive polymer coatings. Nevertheless, this work highlights few advantages drawbacks coatings pathways its potential optimization improvement.