Effect of h-BN Orientation on the Corrosion Resistance of Bioinspired Layered Phosphate Composite Coatings

In this study, we proposed the preparation of phosphate composite coatings (LSPCs) using a Fe3O4/hexagonal boron nitride (h-BN) hybrid, where the ordered dispersion and orientation of h-BN was achieved through a weak magnetic field. The evolution of the physiochemical structure of Fe3O4/h-BN before and after the modification was investigated by FTIR, XRD, XPS, TEM, SEM, and EDS. In addition, the corrosion protection performance of LSPCs was evaluated by electrochemical tests combining the analysis of the microstructure and phase characterization. Results indicate that the nano-Fe3O4 particles are successfully deposited on the surface of h-BN after modification. In addition, electrochemical results confirm that the corrosion protection performance of the layered phosphate composite coating is higher than that of the randomly dispersed coating. That is because the layered structure promotes the densification of the phosphate composite coating, thus delaying the permeation of corrosive media and makes the coatings more protective.