Fabrication of Fine-Grained Structure in Marine Structural Materials Via Friction Stir Processing to Sustain Marine Environments

Aluminum alloys are widely utilized in maritime applications due to their resistance to corrosion and favorable strength-to-weight ratio. However, exposure to harsh marine environments poses challenges such as corrosion, fatigue, and erosion of structural components. Severe plastic deformation (SPD) techniques, including friction stir processing (FSP), offer promising solutions to enhance aluminum alloys’ mechanical properties and corrosion resistance. This study investigates the effectiveness of FSP on AA5083 aluminum alloy, focusing on its microstructural alterations and performance in simulated marine conditions. FSP significantly refines the microstructure of AA5083, improving mechanical properties and corrosion resistance. Immersion, erosion, and exposure tests in seawater demonstrate reduced weight loss, corrosion rate, and erosion rate for FSP-treated samples compared to the base material. Microstructural analysis reveals finer grains and homogenized microstructure in FSP-treated samples, contributing to enhanced corrosion resistance. While FSP-treated samples exhibit reduced corrosion damage and surface degradation in marine environments, further optimization is required to mitigate residual flaws and microstructural heterogeneities for prolonged durability.