To produce power more efficiently and cleanly, the next generation of power and aero turbines along with other essential components will have to operate at extreme temperatures and pressures. Currently advanced single crystal nickel-based superalloys are used in such extreme environments. Even though these components are coated with a bond coat followed by a thermal barrier coating, substrate oxidation and corrosion is a concern. Under these operating conditions alloys are exposed to an aggressive corrosive setting that either shorten component functional lifespan or require the use of thicker components or more costly alloys, resulting in increased cost and reduced efficiency.
While the use of protective thermal barrier and bond coatings has resulted in significant improvements in superalloy performance including thermal, oxidative, and mechanical protection, these coating still allow for oxygen diffusion and subsequent reaction and oxidation with the underlying substrate. NETL has developed a surface treatment process in which reactive metal elements are applied directly to the alloy substrate prior to bond coating, resulting in reduced oxidation. Further, the process significantly increases corrosive resistance of nickel-based superalloys reducing premature component failure resulting in increased system efficiency and cost savings.
