Wettability Analysis of Hydrophobic Micro-dimpled HSS Surfaces

Abstract

Surface hydrophobicity is a significant characteristic of a surface which proves to be a deciding factor for applications in domains such as lubrication retention, wear reduction, self-cleaning properties, fluid drag determination, etc. Texturing a surface governs the surface energy which influences the hydrophobicity of a material. Low surface energy and surface texture with microdimpling has proved to be favorable for enhancing hydrophobicity. In this study, experimental evaluation of texture induced hydrophobicity has been carried out to quantify impact of critical parameters on surface hydrophobicity. The experimentation involved laser texturing of HSS disks to create circle, triangle, and square shaped microdimpled surfaces. The microtextured disks were individually subjected to a drop of distilled water, and drop profile was observed for a time span ranging 0–30 s, to determine the most optimum surface exhibiting the highest contact angle. Among the textured disks subjected to experimentation, it was found that the disk with triangular shaped dimples having parameters (dimple density = 10% and dimple area = 0.01mm2) has displayed maximum hydrophobicity (Contact Angle = 112.6°). Experimentation results confirm that nontextured surfaces are least hydrophobic as compared to either of the textured surfaces, namely circle, triangle and square shaped microdimples. Micro-texturing of HSS surfaces can improve the hydrophobic properties for desired applications.