Investigation of wettability and icing on the steel surface using laser surface treatment

Icing impairs normal functionality for a variety of industries and applications. Research on hydrophobic surfaces is being conducted to solve the icing problem. In this study, a hydrophobic surface was fabricated on SM490A using a nanosecond laser. The change in surface microstructure was observed. Hydrophilicity was immediately observed right after laser irradiation, and the contact angle increased over time, resulting in hydrophobicity. To explain the wettability conversion, X-Ray Photoelectron Spectroscopy (XPS) was used to observe changes in surface chemical composition and element bonding. It was observed that the level of $\text{Fe}$ and $O$ increased immediately after laser irradiation, resulting in surface oxidation. Since the presence of oxides has high surface energies, they contribute to super hydrophilic surfaces. Since the $C-C\left(H\right)$ bond has low surface energy and the content of nonpolar $C-C\left(H\right)$ bonds and $C$ increased over time, the contact angle subsequently increases over time. When the ice shape was observed after dropping a droplet on the surface, the higher contact angle specimen reduced the attached area. Therefore, the surface treatment using a nanosecond laser can produce a hydrophobic surface on the SM490A specimens so that it may solve ice adhesion problems.