Unlubricated Tribological Performance of Aromatic Thermosetting Polyester (ATSP) Coatings Under Different Temperature Conditions

The bearing systems in electrical submersible pumps (ESPs) require high-temperature and high-wear-resistance materials, which can improve the running life of ESPs and reduce the maintenance cost for oil wells. We report on the tribological performance of high-bearing Aromatic Thermosetting Polyester (ATSP) coatings, which were electrostatically spray-coated. ATSP coatings were tested under a sphere-on-disk configuration from room temperature to 260 degrees C. ATSP coatings showed "zero'' wear under moderate load conditions (5 N, 70 MPa) and all temperatures and under higher loading conditions (10 N, 88 MPa) and room temperature. Scanning electron microscopy analysis indicated that the wear of the coating was mainly from burnishing of the asperity peaks of the coating. At the higher load and temperature (10 N, 260 degrees C), the coating failed due to cracks formed by elastic fatigue. For comparison, a commercial thermoplastic PEEK/PTFE coating was also tested under the same conditions. Unlike ATSP, PEEK/PTFE showed abrasive wear grooves and adhesive wear debris under its glass transition temperature. At temperatures higher than its glass transition temperature, PEEK/PTFE showed adhesive wear and plastic deformation.