Real-time and self-monitoring lubricant enabled by the triboluminescence of ZnS:Cu/GF/PTFE composites

Abstract

Unexpected and fatal failure of vital dynamic components in machines happens every day, severely threatening human life and property. Therefore, the development of intelligent self-monitoring lubricants is highly required. In this work, we present a feasible approach to prepare a self-monitoring solid lubricating composite by introducing the triboluminescence (TL) material ZnS:Cu and the reinforced material glass fiber (GF) into a polytetrafluoroethylene (PTFE) solid lubricating material. The introduction of ZnS:Cu could achieve intense TL in the PTFE lubricating materials under mechanical stimuli with enhanced tribological properties. The produced TL signals during lubrication shows good responsiveness to the applied working parameters (load and velocity) with good stability and repeatability, confirming its desirable self-monitoring activities. The TL signal could also be employed to detect the service lifetime of the lubricating medium in solid–liquid lubrication systems. Furthermore, we constructed a TL bearing and simulated the operation process in space, which suggests that the as-fabricated ZnS:Cu/GF/PTFE lubricating composite shows particular application prospects in the aerospace field to ensure the stable and safe running of space equipment.