Anticorrosion Properties of a Novel Hybrid Sol–Gel Coating on Aluminum 3003 Alloy

In this study, a novel hybrid sol–gel coating on AA3003 substrate was developed and the effects of various waste material additives on the reinforcement of the sol–gel coating and the anticorrosion properties in the saline medium were investigated. Egg shell, crumb rubber, activated carbon obtained for pyrolysis of waste rubber tire, waste rubber tire, cement kiln dust, and ST100 additives were tested as reinforcement materials. The AFM characterization results of the coating formulations on AA3003 alloy revealed enhanced roughness values for the modified coatings as compared to the base coating. Similarly, no significant changes were detected in the Fourier transform infrared spectroscopy (FTIR) absorption peaks of the hybrid polymeric material upon loading it with the waste additives, while slight changes in the hydrophobic properties of the final modified coatings were observed as a result of the modification process. Electrochemical impedance spectroscopy (EIS) results revealed that the hybrid sol–gel coating had a promising potential for the protection of the AA3003 substrate against corrosion in the saline medium. However, the loaded additives negatively affected the corrosion resistance properties of the parent hybrid sol–gel coating. For instance, the egg shell additive had the least negative effect on the barrier properties, whereas the cured coating layer of the sample loaded with cement and clay additives showed some disintegration, inhomogeneity, and low barrier properties on the metal surface.