Laser Texturing of Plasma Electrolytically Oxidized Aluminum 6061 Surfaces for Improved Hydrophobicity

Abstract

Laser surface texturing of plasma electrolytically oxidized aluminum 6061 alloy has been carried out through a controlled surface ablation under a high pressure nitrogen gas assistance. Morphological and metallurgical changes in the laser-treated region were examined using optical, scanning electron, and atomic force microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction phase analysis. The hydrophobicity of the textured surface was assessed through water droplet contact angle measurements. It was found that a dense layer with a nanotexture/microtexture is developed at the surface after the laser treatment process. The assessment of the surface characteristics reveals that a superhydrophobic surface results from the laser treatment process; in which case, high water droplet contact angles are measured over the treated surface, which can be explained by known models of texture-induced superhydrophobicity.