Additive friction stir deposition (AFSD) is a novel additive manufacturing technique that enables the fabrication of components in the solid state. Given the benefits of AFSD, understanding the behavior of various feedstock materials after undergoing the AFSD process is crucial for optimizing their performance in structural applications. This study aims to evaluate the effects of AFSD on an Al–Mg alloy, Al5086, comparing it to its initial H32 condition to assess the changes in mechanical properties, microstructure, corrosion resistance, microhardness, and electrical conductivity. Tensile testing showed a 23% reduction in yield strength for as-deposited samples, while ultimate tensile strength remained comparable to the feedstock. Ductility improved significantly, with elongation to failure increasing by 77%, attributed to grain refinement and dynamic recovery. Microhardness decreased by 16% in lower layers due to thermal exposure, but electrical conductivity remained stable, indicating minimal solute atom redistribution. The Nitric Acid Mass Loss Test (NAMLT) revealed a 245% increase in corrosion rate for the AFSD material, linked to the higher density of grain boundaries acting as pathways for corrosion. These findings highlight AFSD’s potential for improving ductility and formability. However, they underscore the need for optimization to reduce corrosion susceptibility and address mechanical strength trade-offs. Future work should focus on fine-tuning process parameters or implementing post-treatment methods to enhance corrosion and mechanical performance.

Additive friction stir deposition (AFSD) is a solid-state additive manufacturing process that enables the fabrication of fully dense metallic components without common fusion-related defects. Inconel 718, widely used in aerospace and energy sectors, requires high structural reliability; therefore, evaluating its response to AFSD is essential for advanced applications. This study investigates the effects of AFSD on IN718 by comparing the mechanical properties and microstructure of the as-deposited material with the feedstock condition. Tensile testing showed that the ultimate tensile strength (UTS) increased by 5% along the traverse direction, whereas elongation was reduced compared to the feedstock. In contrast, build-direction tensile specimens exhibited lower UTS and substantially reduced elongation, revealing mechanical anisotropy. Microhardness increased by 20%, consistent with substantial grain refinement from 11 µm to 3 µm due to dynamic recrystallization during deposition. X-ray diffraction (XRD) revealed no clearly detectable secondary phase formation after AFSD within the resolution limits of conventional XRD, suggesting that the increased hardness and traverse-direction strength can be partly explained by grain refinement. Elemental mapping detected oxygen-enriched Al/Ti regions at interlayer boundaries, which may contribute to the reduced build-direction ductility. Overall, AFSD refined the microstructure, enhanced hardness, and improved traverse-direction strength, while build-direction tensile testing revealed anisotropic mechanical behavior.