Anisotropic wettability of laser micro-grooved SiC surfaces

Wettability on silicon carbide (SiC) substrates with laser processing micro-groove-liked structures was introduced to discuss the anisotropic wetting properties. The surface topography and chemical composition, on the polished and textured substrates were measured by energy dispersive X-ray analysis (EDX) and Raman measurement system (RS), respectively. Water contact angles in both parallel and perpendicular direction to grooves were also measured. Results show that chemical composition on the laser processed surface was almost the same with that on the polished surface, except for the content of O increased and the Si decreased. The contact angle in the parallel direction was larger than the perpendicular direction which indicates that the anisotropy was significant on the groove-liked textures. The difference of contact angle value between these two directions ranged from 15.7° to 47.4°. While the difference would be less than 24°, when both groove spacing and width were larger than 100 μm. The less the size of groove spacing and width was, the more obvious the anisotropy became. The findings may produce a promising way to reduce water adsorption on the gas seal surfaces.