Enhanced corrosion resistance and mechanical behavior in AA2024-T3 alloy composite via friction stir processing with Zn incorporation

This study focused on enhancing the corrosion resistance of Zn-reinforced, multi-pass friction stir-processed 6 mm AA2024-T3 plates. Influence of FSP passes and Zn microparticle incorporation on composite corrosion behavior in 3.5% NaCl solution. Microstructural analysis was performed using optical microscopy (OM) and field-emission scanning electron microscopy with energy-dispersive spectroscopy (FESEM–EDS). The corrosion behavior was assessed through potentiodynamic polarization and cyclic voltammetry. The results indicated an increased corrosion resistance in the second pass, followed by a reduction in the third pass. This trend aligns with the dissolution of Al 2 CuMg intermetallics and the formation of corrosion-resistant AlZn and CuZn compounds, as confirmed by the XRD analysis. Grain size analysis reveals substantial reduction in the first and second passes (39.2 μm to 7.6 μm and 4.2 μm, respectively), with no significant change in the third pass. The application of FSP on AA2024-Zn composite enhanced the tensile strength by 31% in comparison to base material due to the uniform distribution of Zn micro particles and grain refinement of aluminum matrix.