Kinetics of thermal barrier oxide interactions with molten silicates
June 24-29, 2018
The degradation of thermal barrier coatings (TBCs) by molten silicates (CMAS) represents a significant barrier to increased operation temperatures of gas turbine engines and thus fuel efficiency. A promising mechanism for CMAS mitigation has been found in certain TBC chemistries (e.g. Gd2Zr2O7) that undergo reactive crystallization – the crystallization of new, thermodynamically favored phases, which contain both melt and TBC constituents (e.g. apatite). Significant work has been undertaken to understand the thermodynamics of TBC-CMAS systems and the possible reaction phases, but little quantitative data on the kinetics of these interactions exists today; this includes: the (i) rate of TBC dissolution into the melt, (ii) diffusion of TBC constituents within the melt, and (iii) reaction product crystallization rates.
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Collin S. Holgate, David Poerschke, and David Poerschke, "Kinetics of thermal barrier oxide interactions with molten silicates" 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/15