High-Temperature Oxidation-Resistant Composite Coatings for Extreme Environments: Material Systems, Design Strategies, Preparation Technologies, Performance Characterizations, and Research Challenges

With the development of aerospace, energy and power, nuclear energy, and chemical industries, hot-end components of various key equipment are gradually facing more severe high-temperature challenges. The high-temperature oxidation failure of key thermal structural materials in hot-end components has become a critical bottleneck restricting their service life. Consequently, there is an urgent need for oxidation protection of these components. Oxidation-resistant composite coatings are widely recognized as one of the most effective approaches to mitigating high-temperature oxidation. This review initially outlines the characteristics and anti-oxidation mechanisms of various coating materials, followed by an in-depth examination of the impact of structural modifications such as multi-layer/gradient design, diffusion barriers, and self-healing structures on the anti-oxidation efficacy of coatings. Furthermore, it discusses the fundamental principles and key features of advanced coating fabrication techniques, as well as summarizes the methods for characterizing the performance of anti-oxidation composite coatings under real operating conditions. Lastly, the review analyzes the current limitations and challenges facing anti-oxidation coatings in practical applications and provides insights into future development prospects.