Optimization tribology performance of PTFE/PU composite coatings: coating structure and tribological conditions

Abstract Bonded solid lubricant coatings are widely used to reduce friction and wear. However, the tribological properties and wear mechanisms of polytetrafluoroethylene (PTFE)/polyurethane (PU) composite coatings lack comprehensive study, limiting their industrial application. In this work, a series of PTFE/PU composite coatings with different mass ratios were prepared using PU as the matrix and PTFE as a solid lubricant. Their tribological properties were systematically investigated under varying operating conditions. Result show that the coating with a PTFE content of 1.2 exhibited the optimal overall performance, characterized by a low friction coefficient (approximately 0.12) and the minimum wear rate (5.09 × 10 −5 mm 3 (N −1 ·m −1 )), which is about 9.88% lower than that of the coating with PTFE content of 1.4. Further studies showed that the tribological behavior is significantly influenced by load and speed thresholds. The coating performs best under moderate loads (around 5 N) and low to medium sliding speeds (20–60 mm s −1 ). This study elucidates the relationship between composition, working conditions, and tribological performance of PTFE/PU coatings, providing theoretical guidance for designing wear-resistant coatings for industrial equipment.