Fabrication of super-hydrophobic and highly oleophobic Ti-6Al-4 V surfaces by a hybrid method

Abstract

In this study, the super-hydrophobic and highly oleophobic surfaces were fabricated on Ti-6Al-4V substrate by a hybrid method, which combined laser texturing followed by silanization treatment. To fabricate super-hydrophobic and oleophobic surfaces more accurately and effectively, three series of experiments have been carried out to determine the laser parameters for the fabrication of surfaces with the best wettability. Surface wettability was assessed by water contact angle, glycerin contact angle and the n-hexadecane contact angle. To investigate the laser texturing microstructure features and effects thereof on wettability, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and white light confocal scanning microscopy measurements were utilized to characterize the modifications of morphologic, chemical compositions and 3D profiles. The surface with best wettability presented a water contact angle of 153.3°, glycerin contact angle of 149.7°, and n-hexadecane contact angle of 136.6° was successfully achieved by setting the laser parameters to: distance between adjacent laser passes at 60 μm, output power at 12 W and scanning speed at 300 mm/s. The effect of corrosion and abrasion on wettability was also evaluated. Stability tests prove that the super-hydrophobic and oleophobic surfaces possess corrosion/abrasion resistance and good chemical and mechanical stability.