The laser-prepared SiC nanocoating: preparation, properties and high-temperature oxidation performance

In this study, SiC nanocoatings were prepared on graphite substrates via a laser treatment process. Different laser energy densities were employed in the laser treatment. The surface morphology and elemental composition were systematically studied by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM) were used to characterize the phase composition and coating microstructure. A high-temperature oxidation test was also conducted to determine their anti-oxidation performance. The results show that laser irradiation triggers the transformation from micro SiC particles into SiC nanocoating consisting of numerous polycrystalline SiC nanoparticles. At the laser energy density of 10.42 kJ cm(-2), the prepared SiC nanocoating reveals the best oxidation resistance at a high-temperature environment in tested samples. In addition to its dense and crack-free surface morphology, the formation of SiO2 in the SiC nanocoating also helped to enhance the high-temperature oxidation resistance as a self-healing agent. Laser preparation of SiC nanocoating enhances the high-temperature oxidation resistance and protects the underneath graphite substrate, which serves as an efficient and effective manufacturing method for SiC protective coatings.