Computational Design of Impact Resistant Environmental Barrier Coatings for Ceramic Matrix Composites

Environmental barrier coated (EBC) SiC fiber-based ceramic matrix composites (CMC) are targeted for use in propulsion and power applications because of their high temperature capability, creep resistance and high thermal conductivity. However EBCs have been shown to be highly susceptible to foreign object damage (FOD), upon particle impact, leading to EBC spallation and subsequent rapid degradation of the underlying CMC. Under the proposed SBIR program, QuesTek Innovations LLC, a leader in the field of materials design, proposes to develop novel EBCs for Si-based CMCs to achieve enhanced impact/erosion resistance at elevated temperatures. Computational investigations of FOD in thermal barrier coatings (TBCs) have demonstrated that lowering the high temperature hardness and enhancing the toughness of the TBCs reduces the severity of FOD and improves resistance to spallation. QuesTek proposes to utilize novel intrinsic and extrinsic toughening strategies to enhance the impact resistance of EBCs. In the program QuesTek will partner with a leading OEM to provide the role of “voice of the customer” to define the material requirement matrix, processing requirements, and ultimately lead the material implementation. Concept feasibility will be established by impact tests and environmental oxidation tests on prototype coating designs fabricated at coupon-scale in the Phase I program.