Thermal Barrier Coatings and Claddings for Aerospace Applications in Extreme Environment

Thermal barrier coatings (TBCs) and claddings play a pivotal role in advancing aerospace engineering, by enhancing the thermal, mechanical, and environmental resilience of structural components operating under extreme service conditions. This chapter provides a comprehensive overview of the materials, structures, and functional roles of TBCs and metallic claddings in aerospace systems. It begins with the fundamentals of TBC design, detailing the typical multilayer architecture comprising bond coats and ceramic topcoats, followed by the essential thermophysical properties required for high-performance operation. The chapter further explores the applications and alloy systems used for cladding in components such as fuselage panels, turbine blades, and engine housings. Various deposition techniques, including plasma spraying, electron beam physical vapor deposition (EB-PVD), laser cladding, and directed energy deposition (DED), are discussed in terms of their influence on coating microstructure and durability. Emphasis is placed on modeling strategies such as finite element analysis and multiscale simulations to predict stress evolution, failure mechanisms, and service life. Detailed discussion is also provided on common degradation modes, including spallation, delamination, CMAS attack, oxidation, and erosion, along with their mitigation approaches. The chapter highlights sustainability considerations in terms of materials selection, energy-efficient processing, and end-of-life recycling. Future trends, such as functionally graded materials, smart coatings with embedded sensors, nanoengineered architectures, and machine learning–driven predictive maintenance, are explored.