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

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.