Investigation of Tribological and Corrosion Properties of Carbon Nanotube Reinforced Chemically Bonded Phosphate Ceramic Coatings

In this paper, chemically bonded phosphate ceramic coatings (CBPCs) with the addition of carbon nanotubes (CNTs) were prepared on the mild steel (Q235) through 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 because CNTs can effectively hinder the 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 because that CNTs can help CBPCs to get denser and more compact microstructure, which is contributed to prolong the electrolyte diffusion path. Besides, 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.