Investigating the correlation between surface wettability and morphology parameters of femtosecond laser processed on YT15

Investigating the wettability of the tool surface made of cemented carbide is of great significance to improve its working life and quality. The micropit array was processed on the surface of cemented carbide YT15 by a 1064 nm femtosecond pulse laser. Then, the optical microscope, the optical profilometer, and the contact angle measuring instrument were applied to measure the surface morphology and the surface contact angle of micropits. The influence of different laser parameters on surface morphology and the surface contact angle was studied. The geometric morphology model of the micropit was established. The influence of the morphology of micropits on the surface contact angle is analyzed based on the Wenzel theory. The results show that the radius and depth of micropits have a positive correlation with the average laser power and scanning times. As the spacing increases, the surface roughness factor and the surface contact angle decrease. There is a strong correlation between the characterization parameters kurtosis, skewness, and surface wettability in a 3D height parameter system. The smaller the kurtosis, the greater the skewness and the better the surface hydrophilicity.