The Modification and Self-Lubricating Properties of CNTs-Enhanced PEEK Porous Composites Based on FDM

Porous composites utilize their unique pore structures to effectively store and release lubricants, providing a fundamental mechanism for continuous lubrication in self-lubricating bearing cages. This study investigates carbon nanotube (CNT)-reinforced PEEK porous composites fabricated by fused deposition modeling (FDM) and subsequently subjected to heat treatment to improve tribological properties. Results show that incorporating 3 wt% CNTs significantly enlarges average pore size from 0.08 μm to 11.62 μm and increases porosity, resulting in an oil retention rate exceeding 80%. The composites achieve a 26.4–63.4% reduction in friction coefficient under dry sliding conditions at room temperature. After heat treatment, the material maintains a stable friction coefficient below 0.30 during high-temperature dry friction, demonstrating excellent lubricant slow-release capability and thermal stability.