Advances in coating design for high-performance gas turbines

Surface Engineering is now a key materials technology in design of future advanced gas-turbine engines. This article focuses on coating systems for hot-gas-path components, which can vary from low-cost aluminide diffusion coatings to the more exotic, and therefore expensive, thermal-barrier coatings. Available coating systems and their relative benefits are reviewed in terms of performance against manufacturing complexity and cost. Future trends in the design of environmental- and thermal- protection coatings are discussed, including the addition of multiple reactive elements modified aluminide coatings, diffusion-barrier concepts, the design of "smart" corrosion-resisitent coatings, and the development of structurally modified, low-thermal-conductivity thermal-barrier coatings.