Thermal-sprayed ceramic/fluoropolymer coatings with tight bond and self-lubrication: Microstructure, tribological properties, and lubrication mechanism

Ceramic/fluoropolymer composite coatings capable of controlling friction and wear have attracted the attention of numerous researchers. However, their practical applications are significantly limited by the complex fabrication process and weak interfacial bonding between ceramics and fluoropolymers. Herein, the robustly bonded Al2O3/Polytetrafluoroethylene (PFA) composite coatings were fabricated via a straightforward technology, and a comprehensive investigation was conducted to scrutinize their microstructure, tribological behaviors, and lubrication mechanism. Results show that forming an interdiffusion layer between Al2O3 and PFA splats could be responsible for robust interfacial bonding. The generation of a well-covered unique lubricant film at the frictional interface enables the coefficient of friction to be reduced by 83.7 % to 0.13, and the specific wear rate correspondingly diminished from 2.69 × 10−4 mm3 N−1 m−1 to 4.93 × 10−6 mm3 N−1 m−1. The lubricant film is composed of numerous spherical structures and a layer of amorphous material. The development of the hybrid coating with a simple and efficient preparation method, strong bonding, and excellent tribological properties offers significant potential for applications in the field of tribology.