Application of HRTEM to studies of electronic structure and atomic configuration of interface in SiC/SiC composites

The continuous fiber ceramic composite (CFCC), such as SiC/SiC composites have attractive features for advanced energy conversion and production systems, especially gas turbines and fusion power reactors. Because SiC is well known to exhibit a quite fast decay behavior and an excellent oxidation resistance behavior due to the formation of a passive SiO2 layer. The variety of criteria for environmental effects of microstructural evolution at interface of SiC/SiC composites is proposed. Of interest is that the degradation of the composite is observed after annealed at 1500 degrees C under ultra high purity Ar flow condition. However there are few data of nano-structure analyses at interface of SiC/SiC composites. In this work, the environmental effects of microstructural evolution in SiC/SiC composites are examined by a Field Emission type High-Resolution Electron Microscopy (FE-HRTEM) and a Parallel Electron Energy Loss Spectroscopy (PEELS). A possible mechanism for this degradation is discussed and proposed.