Formation of bionic surface textures composed by micro-channels using nanosecond laser on Si3N4-based ceramics

Abstract

Bionic surface textures exhibit excellent properties in improving the friction and wear resistance. To obtain the micro-channel bionic textures with high-quality on Si3N4/TiC ceramic surface, the effect of laser process parameters by using a nanosecond laser with 1064 nm wavelength on micro-channel surface quality and geometry is studied. The surface morphology, depth and width of the micro-channels are examined by scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM). The surface compositions of heat-affected are detected by energy dispersive spectrometer (EDS). Results show that the surface morphology and geometry of the micro-channels are seriously influenced by the laser process parameters. Higher laser power, lower scanning speed, higher frequency and overscan are prone to produce larger channel depth and width due to more accumulated energies. The optimal laser process parameters of the micro-channels are obtained, correspondingly the micro-channel depth and width are about 40–45 μm and 55–60 μm, respectively; meanwhile, it is found that the oxidation occurs in the heat-affected zone. Finally, five kinds of bionic surface textures orderly composed by micro-channels (square, circle, diamond, hexagon and sector) are fabricated on Si3N4/TiC ceramic surface based on the optimal laser process parameters.