Nanohybrid of h‐BN nanosheets supporting CeO₂ enhanced epoxy composite coatings with excellent self‐lubricating performance

Abstract Polymer self‐lubricating composite coatings have been widely used on the surface of machinery to extend the life of the moving systems/parts by controlling friction and wear. In this work, epoxy nanocomposite coating with the thickness of about 60 μm was fabricated with addition of hexagonal boron nitride nanosheets (BNNSs)/CeO 2 nanohybrid for enhancement in antifriction and wear resistance. The active BNNSs were first obtained by exfoliating h‐BN with alkaline solution, and then the rare earth oxide of CeO 2 nanoparticles were immobilized on the surface of BNNSs through hydrothermal method. The microstructure morphology and chemical composition of as‐proposed BNNSs/CeO 2 were characterized by field emission scanning electron microscopy, HRTEM, Fourier transform infrared spectroscopy, RS, X‐ray diffraction, and X‐ray photoelectron spectroscopy. And the tribological behaviors of epoxy nanocomposite coatings containing BNNSs, CeO 2 , and BNNSs/CeO 2 were investigated comparatively using ball‐on disc friction tester (MPX‐3). And the 440C stainless‐steel ball with diameter of 8 mm was used as the counterface material. Tribological tests showed that epoxy‐BNNSs/CeO 2 had the best friction and wear reduction properties, and the lowest coefficient of friction and wear rate of epoxy‐based composite coating were achieved when the content of BNNSs/CeO 2 was 0.5 wt%, with 84.9% and 96.3% reduction, respectively. Moreover, the effect of sliding conditions on the tribological performance of epoxy‐BNNSs/CeO 2 was investigated. The corresponding enhancing mechanisms of BNNSs/CeO 2 were discussed as well.