Aluminum alloy AA5456 faces significant vulnerability to intergranular corrosion in marine environments, where a failure mode is driven by anodic β-phase precipitates. This study investigates a novel in-situ strategy utilizing Laser Powder Bed Fusion (LPBF) to deposit sacrificial zinc (Zn) patterns for cathodic protection. Initial LPBF processing resulted in heterogeneous Zn-Al mixing and strong compositional gradients, limiting the anodes' effectiveness compared to pure Zn. Scanning Vibrating Electrode Technique (SVET) results confirmed this heterogeneity, showing localized anodic and cathodic activation within individual dots, though the Zn-rich islands provided overall effective protection for the AA5456 substrate. To enhance performance, a subsequent remelting (RM) technique was introduced. RM minimizes the heterogeneous Zn-Al distribution, promoting improved homogeneity and establishing well-connected zinc dots array for sustained protection. During RM, zinc evaporation was observed, systematically decreasing surface Zn concentration and shifting the electrochemical potential toward a favorable passivation region. Electrochemical testing confirmed that the RM approach significantly enhances the protective capabilities of the Zn-islands, demonstrating a scalable path toward developing robust, long-term sacrificial anodes for AA5456 in aggressive marine applications.
