Improvement of corrosion resistance of AA2024-T3 using femtosecond laser peening without protective and confining medium

This work reports for the first time the effect of femtosecond laser shock peening (fLSP) without a sacrificial overlay under atmospheric conditions (no confinement) on the corrosion behaviour of AA2024-T3. After fLSP and additional exposure to air a superhydrophobic state (theta = 160 +/- 4 degrees) is achieved. Moreover, fLSPed corrosion-resistant surface contributes to increased polarization resistance, reduced corrosion current and lower anodic dissolution, with long-term stability in aggressive chloride solution. Furthermore, SEM/EDS characterisation reveals reduction in pitting and complete eradication of intergranular corrosion (IGC) attack due to reduced metal/electrolyte contact area and homogeneous, refined microstructure which prevents chain-link IGC propagation.