Study of Microstructure and Corrosion of Friction-Surfaced Aa5083

Friction surfacing (FS) is a solid-state additive manufacturing technique that produces fine-grained coatings, but the microstructural gradients generated across the deposit can affect its corrosion resistance. This study correlates the FS characteristic local microstructure of the advancing side (AS), retreating side (RS) and center of a multi-layer AA5083 deposit with its corrosion after immersion in 0.2 mol L−1 AlCl3 (pH 2.83) for 24 hours. EBSD showed recrystallized, equiaxed grains, with a smaller average size at the AS (3.30 μm) than at the RS (3.55 μm) and the center (3.68 μm). Backscattered electron images revealed a non-uniform distribution of Fe-and Mn-rich intermetallics, with more coarse particles at the AS. Immersion revealed attack concentrated at the inter-layer boundaries and RS/AS edges, following the flow lines of each pass, while the layer centers were less attacked. SEM confirmed selective dissolution along these boundaries. At the micrometric scale, the center showed the highest density of small pits, indicating localized attack, whereas the AS showed a lower density, suggesting more generalized corrosion, with the RS in an intermediate position.