The effect of TiO2 as a pigment in a polyurethane/polysiloxane hybrid coating/aluminum interface based on damage evolution

The addition of TiO2 produced hydrophobicity functionality, and TiO2 acted as a physical barrier layer that influenced the initial damage stage. Different exposure times were associated the different stages of damage evolution for the hybrid coating and coating/substrate interfaces. Electrochemical testing with high-resolution techniques such as AFM (atomic force microscope) and IFM (infinite focus microscope) characterized the coating surface and the interface performance and resolved the surface and defect formation observed with different levels of TiO2 content. Of the systems tested, the system with 10 wt% TiO2 provided the best corrosion inhibition.