Tribological properties and wear mechanisms of HVOF-sprayed FeCrCB-BNNSs composite coatings

The application of FeCrCB coatings on critical components such as bearings and gears can improve wear resistance, corrosion resistance, and oxidation resistance, yet their tribological performance under extreme operating conditions still requires further enhancement. In this study, different contents of BNNSs were incorporated into FeCrCB to prepare composite coatings, utilizing the excellent lubricity derived from their layered structure to improve wear resistance. Morphological characterization and wear analysis show that the composite coatings containing BNNSs exhibit significantly improved wear resistance, among which the FeCrCB-0.1 vol% BNNSs coating performs the best, with a wear rate reduction of 27.64% compared to the FeCrCB coating. This improvement is attributed to the extremely weak interlayer forces of BNNSs, which endow them with excellent self-lubricating properties. However, excessive BNNSs content reduces the interlayer bonding strength of the coating, leading to increased porosity and decreased thickness, thereby impairing wear resistance. This study provides theoretical guidance and experimental support for the application of FeCrCB coatings under harsh conditions and offers new insights into the functional design of two-dimensional nanomaterials in iron-based coatings.