Investigations on Electrochemical Corrosion Behavior of 7075 Aluminum Alloy with Femtosecond Laser Modification

The effects of the surface integrity of 7075 aluminum alloy by femtosecond laser modification (FLM) were investigated, and subsequently the electrochemical corrosion behavior of the samples in 3.5 % NaCl solution. It was found that hydrophobic textures, amorphous oxidative layers, and deformed layers were formed sequentially from the outside to the inside of the treated samples. These help to reduce the solid-liquid contact area on the surface, improve the polarization resistance, reduce the corrosion current, impede the diffusion of chloride in the interior, and thus enhance the corrosion resistance of the aluminum alloy. Additionally, it was determined that the contribution of hydrophobic textures and amorphous oxidative layers to the enhancement of corrosion resistance was dominant.