Thermal Barrier Coatings for High-Temperature Applications

Thermal barrier coatings (TBCs) are advanced ceramic systems engineered to protect metallic and composite components operating at extreme temperatures, typically above 1000 °C. By introducing a multilayer architecture—comprising a ceramic top coat, metallic bond coat and underlying substrate—TBCs reduce heat flux, mitigate high-temperature corrosion and extend service life in gas turbines, aeroengines and industrial furnaces. Conventional top-coat materials such as yttria-stabilised zirconia exhibit low thermal conductivity and favourable thermal expansion but suffer from phase instability, sintering and spallation under cyclic thermal loading. Environmental barrier coatings (EBCs) have been developed to protect silicon-based ceramic matrix composites from oxidation and calcia-magnesia-aluminosilicate (CMAS) attack. Recent advances focus on tailored chemistries—such as high-entropy ceramics and rare-earth silicates—innovative microstructures and novel deposition techniques to enhance phase stability, strain tolerance and CMAS resistance, thereby supporting higher operating temperatures and improved efficiency in energy and propulsion systems.

Research from Nature Portfolio

Recent studies have demonstrated that the design of β-phase rare-earth disilicates can be guided by configurational entropy of mixing. High-throughput density functional theory calculations reveal that an optimised combination of multiple principal rare-earth cations within a β-type lattice suppresses polymorphic transformations and stabilises the desired phase. This entropy-driven approach enables the rational selection of compositions that maintain low thermal conductivity while resisting high-temperature phase changes, offering a predictive framework for the next generation of environmental barrier coatings.

Thermal Barrier Coatings for High-Temperature Applications publication trend

The graph below shows the total number of articles in thermal barrier coatings for high-temperature applications across all publications each year (not limited to Nature Index journals).

Technical terms

Thermal barrier coating (TBC): A multilayer ceramic system applied to protect substrates from extreme heat by reducing thermal flux and preventing oxidation.

Environmental barrier coating (EBC): A silicate-based protective layer designed to shield silicon-based ceramic composites from high-temperature corrosion and CMAS attack.

Calcia-magnesia-aluminosilicate (CMAS): A molten glassy deposit formed from environmental contaminants that infiltrates and degrades coatings at high temperature.

Configurational entropy of mixing: A thermodynamic descriptor expressing the degree of atomic disorder in a multicomponent solid solution, used to predict phase stability.

Sintering: The densification of ceramic particles at elevated temperatures, which can reduce coating porosity and strain tolerance under thermal cycling.

References

1. Thermal properties and calcium-magnesium-alumino-silicate (CMAS) interaction of novel γ-phase ytterbium-doped yttrium disilicate (γ-Y1.5Yb0.5Si2O7) environmental barrier coating material. Advanced Composites and Hybrid Materials (2024).
2. Phase formation capability and compositional design of β-phase multiple rare-earth principal component disilicates. Nature Communications (2023).
3. A review on environmental barrier coatings: History, current state of the art and future developments. Journal of the European Ceramic Society (2021).
4. High-entropy pyrochlores with low thermal conductivity for thermal barrier coating materials. Journal of Advanced Ceramics (2019).
5. Progress in ceramic materials and structure design toward advanced thermal barrier coatings. Journal of Advanced Ceramics (2022).