Enhancing high-temperature resistance of electrophoretic coatings through cerium oxide incorporation

Electrophoretic paints, by virtue of their low cost, straightforward processing and excellent resistance to weathering and pollution, have found extensive application across a wide range of industries. However, their applications are limited by poor thermal stability. To address these issues, this study investigated the preparation and properties of electrophoretic paint/CeO 2 composite coatings fabricated through a one-step electrophoretic deposition method, focusing on the impact of cerium acetate concentration and different cerium compounds (cerium acetate versus CeO 2 nanoparticles) on coating performance. Results revealed that, relative to neat electrophoretic coatings, the addition of cerium compounds markedly improved thermal stability, corrosion resistance and autonomous self-healing capability. The optimal concentration of cerium acetate was determined to be between 0.001 and 0.01 M, within which the coatings exhibited uniform and dense surfaces. Higher concentrations led to particle agglomeration and surface defects. The addition of cerium acetate increased the char yield from 36.13% to 55.54% at 800 °C and reduced the corrosion current density by a factor of ten. Additionally, the coatings demonstrated self-healing capabilities, with cracks healing following thermal treatment at 200 °C. Flame retardancy was also improved, demonstrated by a reduction in the peak heat release rate from 340.9 W/g to 240.6 W/g. In summary, cerium acetate was found to be more effective than CeO 2 nanoparticles in enhancing coating performance. These enhancements make electrophoretic paint/CeO 2 composite coatings highly suitable for high-temperature applications.