ECI Digital Archives

Title

High temperature interactions between environmental barrier coating (EBC) ceramics and calcia-magnesia-alumina-silicate (CMAS) glass

Authors

Laura R. Turcer, Brown UniversityFollow
Hector Garces, Brown University
Lin Zhang, Brown University
Nitin P. Padture, Brown University
Amanda R. Krause, Brown University

Conference Dates

June 24-29, 2018

Abstract

Ceramic-matrix-composites (CMCs) are being researched to replace current metallic hot-section components, which would allow for higher operating temperatures. Due to the oxidation of CMCs (usually SiC-based) in the presence of water vapor, dense environmental barrier coatings (EBCs) are needed. At temperatures above 1200 °C, silicate particles (sand, volcanic ash, fly ash, etc.) enter the engine, melt on the hot surfaces and form calcia-magnesia-alumina-silicate (CMAS) glass deposits. The molten CMAS glass can penetrate grain boundaries and cause dissolution, which leads to premature failure. New coatings are needed to protect CMCs from CMAS attack.

A new model, based on optical basicities, has been used to predict the reactivity between CMAS and potential EBC ceramics. Based on this analysis, several potential EBC ceramics have been identified: yttrium aluminate (YAlO₃), yttrium disilicate (g-Y₂Si₂O₇), ytterbium disilicate (b-Yb₂Si₂O₇), and scandium disilicate (b-Sc₂Si₂O₇).

Please click Additional Files below to see the full abstract.

Recommended Citation

Laura R. Turcer, Hector Garces, Lin Zhang, Nitin P. Padture, and Amanda R. Krause, "High temperature interactions between environmental barrier coating (EBC) ceramics and calcia-magnesia-alumina-silicate (CMAS) glass" in "Thermal Barrier Coatings V", Prof. Dr. Robert Vaßen, Forschungszentrum Jülich GmbH, Germany Brian Hazel, Pratt & Whitney, USA Prof. Dr. Uwe Schulz, German Aerospace Center, Germany Dr. Michael J. Maloney, Pratt & Whitney, USA Dr. Ram Darolia, GE Aviation (Retired), USA Eds, ECI Symposium Series, (2018). https://dc.engconfintl.org/tbcv/23