Investigation on the effect of laser surface texturing on the wettability of pure zinc substrate

Abstract

Zinc finds a prominent metallic alternative for existing metallic bio-implant materials. Wettability significantly alters the corrosion resistance and cell adhesion of bio-metallic materials. The wettability of the metallic materials can be engineered by laser surface texturing (LST). In this work, nanosecond laser surface texturing experiments were conducted on the pure zinc substrate by varying the laser scan speed and texture pitch. Laser scan speeds were varied from 10 to 50 mm/s, and the texture pitch varied from 100 to 300 µm. A nanosecond 28 W Nd:YAG laser system was used with 1064 nm wavelength, repetition rate of 5 kHz, focal length of 234 mm, and pulse width of 2 ms. The white light interferometer (WLI) was utilized to explore the surface roughness of the textured samples, and the scanning electron microscope (SEM) was used to investigate the surface morphology. The results revealed that LST on pure zinc follows the Weinzel model which enhances the hydrophobic nature of its surface. Surface roughness plays a significant role in improving the hydrophobic nature of the LST zinc substrates.