Stable Bond Coats for 2700oF EBC Coated SiC/SiC CMCs

ABSTRACT: Technology Assessment and Transfer will demonstrate the potential of bond coats that are capable of providing long durability at 2700oF for environment barrier coated (EBC) SiC/SiC CMCs.A systematic approach with a high probability of success includes the following: selection of high temperature stable oxides and silicates, magnetron sputtering, the ideal method for depositing thin, adherent single and multilayer coatings on SiC/SiC substrates; comprehensive characterization methods - XRD, SEM, EDS to optimize coating chemistry and microstructure; elevated isothermal and thermal cycling tests of coated SiC/SiC coupons in a 50/50 air/water vapor environment to determine and compare the capabilities and potential ofthe experimental bond coats for improved EBCand SiC/SiC CMC performance.; BENEFIT: The proposed bond coatings offer a broad range of technical, social and commercial benefits Economic benefits will result from lower fuel consumption and extended equipment life.Technical and economic benefits include improved turbine engine performance, lower fuel consumption reduced maintenance and parts replacements.Environmental (GREEN) benefits will result from reduced emissions and particulates and reductions in the negative life cycle environmental impacts of the increased maintenance.The commercial impacts include improved competitiveness and sales of turbine engines, reductions in fuel consumption per mile and climate damaging by-products . Consequently, the technical and commercial benefits in energy savings and associated environmental impacts combine to offer major societal payoffs.