Structural optimization and wetting behavior of femtosecond laser-fabricated micro-cone arrays on marine steel

Abstract

To enhance marine equipment durability in harsh conditions, marine steel surfaces with high hydrophobicity are critical for anti-corrosion and self-cleaning, yet existing modification techniques lack stability, controllability, and consistency. Herein, 304 stainless steel substrates were processed via femtosecond laser to fabricate microcone arrays (spacings 150-350 μm, heights 150-350 μm), with systematic characterization of morphology, composition, crystal structure, and hydrophobicity. Results show regular micro-cones with smooth sidewalls (no slag), uniform element distribution, retained austenitic matrix, and minor edge oxidation, as confirmed by energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). Hydrophobicity varied with structure, peaking at 116.37° contact angle and 22° rolling angle, driven by synergistic air entrapment, laser-induced roughness, and oxide layer low surface energy. This work establishes a reliable process-structure-performance correlation, aiding the design of hydrophobic marine steels with strong engineering potential.