Preparation of CNT/PEEK porous composites via NaCl leaching and FDM for bearing cage applications.

Porous composites can store and release lubricants via their unique pore structures, enabling continuous lubrication for self-lubricating bearing cages. In this study, carbon nanotube (CNT)/polyether ether ketone (PEEK) porous self-lubricating bearing cage materials were fabricated using the fused deposition molding (FDM) technique. Their preparation process, microstructure, and properties were systematically investigated. The results demonstrate the initial feasibility of preparing CNT-reinforced PEEK porous composites via FDM with optimized parameters. The incorporation of CNTs effectively modulated the material's structure, increasing the average pore size from 0.08 μm to 11.62 μm and optimizing the porosity within a specific content range. However, higher CNT content resulted in poor extrusion flowability and nozzle clogging. Nevertheless, CNTs significantly enhanced the material's tribological performance while maintaining good mechanical properties. This study provides a theoretical basis and process reference for preparing self-lubricating bearing cages, while also identifying that process optimization and CNT dispersion require further in-depth investigation.