Fabrication of Superhydrophobic Surface on Aluminum Alloy by Sandblasting-anodizing-fluorination

In order to study the influence of main processing parameters of composite method on the surface morphology and superhydrophobicity, sandblasting and anodizing were combined to obtain micro-nano structure on the surface of aluminum alloy. After the treatment of fluorination, the surface showed excellent superhydrophobicity. The results demonstrate that the structure at micron level is fabricated by sandblasting while the structure at nanometer level is prepared by anodizing. However, superhydrophobic surface cannot be achieved just by a rough surface structure or the decoration of polymer with low surface energy, or the combination of the decoration and single microstructure or nanostructre. The combination of the decoration and micro-nano structure is the key to attain superhydrophobicity on aluminum alloy. Gas-trap is intercepted during the contact of the surface with water droplets, which effectively reduces contact area and heat exchange between the surface and water droplets. Condensation of water molecules and corrosion of sea water are therefore slow down, which explains the improvement of frost resistance and corrosion resistance to sea water of the superhydrophobic surface on aluminum alloy.