Fast fabrication of superhydrophobic Ti-6Al-4V surface using Q-switched nanosecond pulsed laser at 1064 nm and cyclohexane.

Superhydrophobic and superhydrophilic surfaces are attracting significant attention in fundamental and applied research. This study fabricated the micro/nanostructure with a Q-switched nanosecond pulsed laser on the Ti-6Al-4V surface. Three laser-generated surface topographies on titanium were produced based on three different pitch sizes (51 μm, 34 μm, and 29 μm). The laser textured surfaces (LTS) were studied in terms of both structure evolution and chemical composition using Field Emission Scanning Electron Microscopy (FE-SEM), Optical Microscopy (OM), Confocal Laser Scanning Microscopy (CLSM), Raman Spectroscopy, and X-ray Diffractometer (XRD). 29 μm pitch displayed the lowest water contact angle of 18.5° and surface roughness of 0.5 μm. This structure was further treated with cyclohexane at different temperatures. The best sample reached superhydrophobicity with a maximum water contact angle of 155.1° immediately after being treated with cyclohexane at the low temperature of 70 °C for 2 h, while the raw surface, for comparison, showed no change in hydrophobicity after being treated with cyclohexane under the same condition. Thus showing clear evidence of a combined effect between LTS and post-treatment. The surface features were assessed to explain the underlying process.