Robust High Temperature Environmental Barrier Coating System for Ceramic Matrix Composite Gas Turbine Components using Affordable Processing Approach

Research is proposed to demonstrate the use of advanced manufacturing techniques to enable the affordable application of multi-functional thermal / environmental barrier coatings (T/EBCs) having enhanced resistance to high temperature combustion environments. T/EBCs are envisioned to protect the surface of Si-based ceramics against moisture-assisted, oxidation-induced ceramic recession. Current T/EBC systems have been demonstrated in long time exposures at ~2400?F substrate temperatures. However, their use at elevated temperatures (i.e. 2700?F substrate temperatures) is limited by the low temperature stability and high diffusion activity of current T/EBC materials. One approach to increase the temperature capability of these systems is the incorporation of multi-layered T/EBC designs. In this Phase I effort, enhanced processing techniques will be employed to demonstrate the manufacture of robust T/EBC bond coat systems using a physical vapor deposition based processing approach which enables improved coating adhesion and advanced coating architectural, compositional and microstructural control, as well as non-line-of-sight (NLOS) deposition. Scaled processing approaches will then be used to demonstrate the deposition of high temperature capable T/EBC bond coats onto components of interest to gas turbine engine manufacturers. These bond coats will then be incorporated into full high temperature capable T/EBC systems planned in Phase II. Finally, concepts to enable the deposition of T/EBC bond coat systems on NLOS internal regions of hollow components will be investigated. This work will significantly aid the incorporation of Si-based ceramic components in gas turbine engines resulting in reduced weight and increased operating temperatures.