Chemically bonded phosphate ceramic coatings (CBPCs) with the addition of carbon nanotubes (CNTs) were prepared on mild steel (Q235) through the sol gel method. The wear and corrosion performance of CBPCs with the addition of CNTs were evaluated by tribological and electrochemical tests combining the analysis of microstructure, phase characterization, and curing behavior. Results indicate CNTs nanofiller significantly enhances the wear and corrosion behavior of CBPCs. The enhancement of wear performance for CBPCs with CNTs nanofiller is produced by the CNTs effectively hindering dislocation movement through the coating and substrate system and the occurrence of plastic deformation owing to their remarkable mechanical and lubricating properties. The enhancement of corrosion performance for CBPCs with CNTs nanofiller is due to the CNTs helping CBPCs to develop a denser and more compact microstructure, which contributes to prolonging the electrolyte diffusion path. In addition, CNTs exhibit excellent hydrophobicity and can absorb oxygen molecules, which prevents the corrosion process on the anode and cathode sections of coating and substrate system.

In this paper, a micro-nano structural ceramic coating with good hydrophobicity and wear resistance was successfully prepared by sol-gel method, which is assisted by pore-forming agent and nanoparticles 1H, 1H, 2H, 2Hperfluorodecyltriethoxysilane modified. The surface morphology, hardness, roughness, wettability, and tribological properties of three different surface coatings were characterized. With the complication of the surface structure, the roughness of the coating increases from 1.30 to 2.05 μm. Under the combined effect of roughness and long hydrophobic chains, the contact angles of the coatings before and after modification under saline conditions increased from 56.31 to 140.59 • (pH4); from 55.58 to 134.40 • (pH7); from 53.80 to 132.26 • (pH10). Through the comparison of wear rate and wear morphology, it is found that the micro-nano structure coating has the lowest wear rate (0.705 × 10 -6 mm 3 ⋅N -1 ⋅s -1 ) and the smallest plastic deformation. This means that in addition to the good hydrophobicity and chemical stability, the micro-nano structure on the surface also improves the wear resistance of the coating.