Preparation and Mechanical Properties of Diamond Films on Textured WC-Co Substrate

The surface texture technology can improve the film-substrate adhesion and material properties by optimizing the surface microstructure of diamond films on WC-Co substrate. Four types of surface textures are fabricated on WC-Co cemented carbide (YG8) substrates using fiber laser processing, and different structural diamond films are deposited on the laser textured and nontextured substrates using the hot filament chemical vapor deposition technique. The structural features and mechanical properties and tribological properties of the textured diamond films are studied. The results show that the wave-shaped texture structure shows the best performance in all experiments. The wave-shaped textured diamond film has excellent adhesion, with few cracks appearing in the nanoindentation test and no significant peeling. The bonding strength is significantly higher than that of other textures. Under the methane concentration (5%), the wave-shaped textured diamond film has uniform particle distribution, dense surface structure, good wear resistance, and the lowest friction coefficient, indicating that the film has excellent self-lubrication and is suitable for use under heavy loads and long-term conditions for precision machining.