Understanding High-Temperature Interactions between EBC Ceramics and CMAS

Ytterbium pyrosilicate (or disilicate) is a promising ceramic for environmental-barrier coatings (EBCs) on ceramic-matrix composite (CMC) components in the hot-section of jet engines. In addition to the various requirements an EBC must satisfy, it must be resistant to high-temperature attack by calcia-magnesia-aluminosilicates (CMASs) ingested by the engine in the form of sand, dust, or ash. These Part I and Part II papers, with Hadas Sternlicht and David W. McComb , describe the new understanding of high-temperature interactions between EBC ceramics and CMAS glass, gained using various electron microscopies and spectroscopies.