A Review on Environmental Barrier Coatings: History, Current State of the Art and Future Developments

TL;DR

This review discusses the development, current state, and future prospects of environmental barrier coatings for SiC/SiC ceramic matrix composites, focusing on their role in enhancing gas turbine efficiency and environmental safety.

Contribution

It provides a comprehensive overview of EBC materials, their interactions with harsh environments, and outlines future research directions for next-generation coatings.

Findings

EBCs enable SiC/SiC CMCs to operate in aggressive environments.

Current EBC compositions are summarized with their environmental interactions.

Future research directions for advanced EBCs are outlined.

Abstract

The increasing demand for more efficient and environmental-friendly gas turbines has driven the development of new strategies for material development. SiC/SiC ceramic matrix composites (CMCs) can fulfil the stringent requirements; however, they require protection from the operating environment and debris ingested during operation. Environmental barrier coatings (EBCs) are a protective measure to enable the CMCs to operate under harsh conditions. EBC-coated CMCs will enable an increased efficiency and reduced pollutant and CO2 emissions. In this review, the fundamentals of SiC/SiC ceramic matrix composites degradation in steam environments and under the presence of molten alkali salts, namely CaO-MgO-Al2O3-SiO2 (CMAS), are first presented. Then, a summary of EBCs along with a comprehensive summary of the current compositions and their interactions with steam and molten salts is presented. Finally, an overview of the latest research directions for the potential next generation of EBCs are outlined