One-step ultrafast laser-induced graphitization on PS-SiC surfaces for superior friction performance

Pressureless sintered silicon carbide (PS-SiC) ceramics are widely used as friction materials in the aerospace industry, and enhancing the self-lubricating properties of PS-SiC ceramics under dry friction is highly significant. In this study, an infrared femtosecond laser was used to treat the surface of PS-SiC ceramics, and the effects of various processing parameters on surface microstructure, chemical composition, and graphitization degree were investigated. More importantly, SiC decomposes into amorphous carbon and stays on the surface of PS-SiC ceramics under the photothermal effect, and the amorphous carbon realizes the transition to the ordered graphite structure by controlling the laser energy. The highly graphitized, carbon-containing micro/nanostructures on the surface of laser-treated PS-SiC ceramics promote the formation of stable carbon-based tribofilms during sliding, which significantly enhances the tribological properties of PS-SiC ceramics under dry friction. This study proposes a method for inducing graphitization on the surface of PS-SiC ceramics using an infrared femtosecond laser, providing a manufacturing approach and theoretical support for the development of high-performance PS-SiC ceramic friction materials.