In this study, progress of ceramic matrix composites (CMCs) for past decades was summarized. Failure behavior of CMCs is completely different from monolithic ceramics by introducing continuous fibers. However, damage evolution process and failure are complicated due to their heterogeneous microstructures. 2D and 3D displacement measurement techniques are effective tool to understand failure process in CMCs.
Recent R&D of environmental barrier coating (EBC) systems to protect CMCs from water vapor in combustion environment was also reviewed. Critical issue in EBC system is formation of cristobalite and its transformation. Further improvement of thermal properties of materials used for top coat layer is necessary for limitation of present system. Compositionally complex ceramics enable to adjust various needs, i.e., reduction of thermal stress due to mismatch of thermal expansion.

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In order to realize a carbon neutral society, substitutional fossil fuels such as hydrogen and ammonia are considered for next-generation gas turbines for power generation. This review describes a brief summary of research-related activities regarding a carbon neutrality and the current status of hydrogen combustion gas turbines especially with a pure oxygen-hydrogen combustion type and ammonia combustion gas turbines. Based on the combustion environment with such alternative fuels, the needs for materials and coating development are discussed.

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