Tribological properties of epoxy composite coatings reinforced with functionalized C-BN and H-BN nanofillers

Highlights: • Regulating the tribological performances of EP composite coatings via tailoring BN filler type, shape, content and operating condition. • APTES was successfully grafted onto C-BN and H-BN for enhancing filler dispersion in the EP. • FC-BN endow the composite coatings the best wear resistance. • FH-BN/EP composite coating exhibited the best friction reduction performance due to its lamella structure. A series of epoxy resin (EP) composite coatings reinforced with functionalized cubic boron nitride (FC-BN) and functionalized hexagonal boron nitride (FH-BN) were fabricated successfully on 316L stainless steel by hand lay-up technique. The structure properties were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The morphologies were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Moreover, UMT-3 tribometer and surface profiler were used to investigate tribological behaviors of as-prepared composite coatings under dry friction and seawater conditions respectively. The results demonstrated that the presence of FC-BN or FH-BN fillers could greatly decrease the friction coefficient (COF) and wear rate of epoxy, in addition, composite coatings possess better tribological properties under seawater condition which was attributed to the lubricating effect of seawater. Moreover, FC-BN endows the composite coatings the highest wear resistance, and FH-BN /EP composite coatings exhibited the best friction reduction performance which is attributed to the self-lubricating performance of lamella structure for FH-BN sheet.