Surface Modification and Performance Study of Dual Ceramic Thermal Barrier Coatings

The proposed aluminum-plated LaMA dual ceramic thermal barrier coating life extension strategy significantly enhances the coating's high-temperature oxidation resistance through aluminum deposition on the LaMA coating surface. The coating was fabricated using a composite technique of plasma spraying and arc ion plating. Detailed characterization of the coating's phase composition, surface morphology, and cross-sectional structure was performed via X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Findings revealed that the aluminum plating treatment significantly reduced microcracks and pores on the coating surface, improved coating density, and enhanced oxidation resistance. In oxidation kinetics testing, the weight gain rate of the aluminum-coated LaMA coating was 4.84 ± 0.23 mg/cm², significantly lower than the 8.39 ± 0.12 mg/cm² of the uncoated sample, indicating that the aluminum layer effectively reduced weight gain under high-temperature oxidation. Further analysis of TGO layer evolution revealed that the aluminum-coated layer effectively retards rapid TGO thickening and mitigates interfacial stress accumulation during oxidation. This demonstrates the significant advantage of aluminum coating in enhancing high-temperature oxidation resistance. These findings provide an effective technical solution for ensuring the long-term reliability of dual-ceramic thermal barrier coatings in high-temperature environments.