Investigation of the Laser Parameters that Should Be Used to Optimize the Root Mean Square Height Value, One of the Roughness Parameters Required to Obtain a More Hydrophobic Surface

This study investigates the effects of fiber laser surface texturing on ST52 steel plates to enhance hydrophobicity by optimizing surface roughness (Sq). Three key parameters—geometric pattern type (square, diamond, hexagon, circle), laser power (40–100 W), and theoretical laser-scanned area factor (20–80%)—were examined using the Taguchi L16 orthogonal array to minimize experimental runs while ensuring statistical validity. The goal was to maximize the Root Mean Square Height (Sq) for improved hydrophobic performance. Results revealed that the hexagonal pattern, 100 W laser power, and 80% scanning area produced the highest Sq value (338.39 µm), with a corresponding signal-to-noise (S/N) ratio of 50.59. ANOVA identified the scanning area factor (39.94%) as the most influential parameter, followed by laser power (34.29%) and pattern type (25.77%). Non-linear trends were observed: Sq peaked at 60 W and 100 W but dipped at 80 W, while the 80% scanning area yielded the roughest surface, and 40% the smoothest. For hydrophobic applications, the optimal combination was circular/diamond patterns, 80% scanning area, and 60 W or 100 W laser power. Conversely, low-friction surfaces required square/hexagonal patterns, 40% scanning area, and 40 W or 80 W power. The study demonstrates the efficacy of fiber laser texturing for tailoring ST52 steel surfaces and underscores the Taguchi method’s utility in parameter optimization.