Picosecond Laser Surface Texturing of Al2024-T3 Substrate for Super-Hydrophobicity

In the paper, 1.06 µm picosecond (ps) laser is employed to fabricate micro/nano surface textures on Al2024-T3 substrate. The effects of different laser parameters including laser fluence, repetition rate, scanning speed, pulse number, focal position, etc. on the topography, feature profile, feature dimensions of the induced surface textures have been studied. The optimum laser parameters have been identified and the uniform-distributed 2 scale micro-nano hierarchical bump array, sub-micron-ripple and micro-dimple array surface patterns are fabricated on the Al2024-T3 substrates. The laser textured Al2024-T3 sample shows stable superhydrophobic property with a water contact angle (WCA) of more than 150 degree and contact angle hysteresis (CAH) of less than 10 degree. The mechanism involved in the process is discussed in terms of surface morphology and surface chemistry. The developed process has the potential to be applied in improving the performance of the Al-based components and/or products in terms of superhydrophobicity and easy cleaning.