Study of laser-induced periodic surface structures on different coatings exhibit super hydrophilicity and reduce friction

Abstract

This study aims to induce a laser-induced periodic surface structure (LIPSS) on different coatings using a picosecond laser. An energy dispersive X-ray (EDX) spectroscopy analysis was performed, and wettability and friction tests were performed. Additionally, the surface electric field intensity (EFI) distribution was analyzed using the finite element method (FEM) to study LIPSS generation on different coating morphologies. The EDX results demonstrated that the LIPSS induced on the TiN coatings did not destroy them; however, the TiCN coatings were oxidized in the LIPSS fabrication process. The numerical simulation results indicated that the surface EFI and depth of the surface roughness were significantly linear, and the EFI was significantly related to the refractive index and extinction coefficient of the coating material. The wettability and friction test results implied that the LIPSS on different coatings could exhibit super hydrophilicity and played a role in friction reduction.