ChEMS Seminar: Barriers to Efficiency -- Thermal-induced Stresses and Phase Evolution in Multiphase Ceramic Coatings

Friday, April 17, 2015 - 10:00 p.m. to Saturday, April 18, 2015 - 10:55 p.m.
McDonnell Douglas Engineering Auditorium (MDEA)
Professor Katherine T. Faber
Department of Materials Science
California Institute of Technology, Pasadena, CA

Silicon-based ceramics are promising candidates for structural components in gas turbine engines to allow higher operating temperatures and greater efficiency than current Ni-based superalloys. However, the passivating oxide (SiO2) that forms on their surface reacts with water vapor present in the combustion atmosphere, causing coating recession and necessitating the use of environmental barrier coatings (EBCs). Often these barriers are multilayered and multiphase to provide optimal thermal expansion match, chemical stability, durability and low diffusivity. They further require chemical inertness in the presence of oxide engine deposits. Faber will report on the use of synchrotron-derived high-energy X-rays to assess internal stresses, phase content and stability in rare-earth silicate multilayer systems. The results offer some guidance toward pathways for more robust ceramic coatings. 

BIO: Katherine Faber is the Simon Ramo Professor of Materials Science at the California Institute of Technology. Her research interests include ceramics for energy-related applications, comprising thermal and environmental barrier coatings for power generation components and porous solids for filters and flow. More recently, she has worked with the Art Institute of Chicago to establish the Northwestern University/Art Institute of Chicago Center for Scientific Studies in the Arts, where advanced materials characterization is used in support of conservation science. After receiving a B.S. in ceramic engineering at Alfred University, she earned an MS in ceramic science at the Pennsylvania State University and a PhD in materials science and engineering from UC Berkeley. Prior to joining the Caltech faculty, she held appointments at the Ohio State University and Northwestern University. Among Professor Faber’s honors are the National Science Foundation’s Presidential Young Investigator Award, selection as Distinguished Life Member of the American Ceramic Society and Fellow of ASM International, the Charles E. MacQuigg Award for Outstanding Teaching at Ohio State, the Society of Women Engineers Distinguished Educator Award, and the YWCA Achievement Award for Education. She served as president of the American Ceramic Society (2006–07), and was elected to the 2014 American Academy of Arts and Sciences class of fellows.