Impermeability of Y3Al5O12 ceramic against molten glassy calcium-magnesium-alumina-silicate

Degradation of thermal barrier coatings (TBCs) caused by calcium-magnesium-aluminasilica (CMAS) glassy penetration is becoming an urgent issue for TBCs industrial applications. In this work, yttrium aluminum garnet (Y3Al5O12, YAG) nano-powders were synthesized through a chemical co-precipitation route. The resistance of YAG ceramic to glassy CMAS infiltration at 1250 degrees C was evaluated. YAG ceramic bulk sintered at 1700 degrees C for 10 h was comprised of a single garnet-type Y3Al5O12 phase. The molten CMAS glass was suppressed on the surface of the YAG ceramic at 1250 degrees C. A chemical reaction between YAG and the molten CMAS glass did not occur at 1250 degrees C for 24 h, suggesting that YAG could act as an impermeable material against glassy CMAS deposits in the TBC field. (C) 2018 Chinese Society of Aeronautics and Astronautics. Production and hosting by Elsevier Ltd.