Plasma Electrolytic Diffusion Coatings for Enhanced Hot Section Life

ABSTRACT: Increasing temperatures, combined with an accelerated demand for reducing weight in the engine, is creating new problems that require innovative solutions. As temperatures increase, oxidation and hot corrosion of compressor, combustor and turbine section components are becoming increasingly acute, limiting the effectiveness of current aluminide coatings on nickel alloys. Salt-deposit-induced hot corrosion in particular has become an intensive area of emphasis for OEMs, as at increased temperatures, combined with mechanical stresses, new chemical reactions with both environmental coatings and metal substrates creates an accelerated corrosion condition. In order to provide a more complete solution for both oxidation and hot corrosion performance of modern high-temperature superalloys, IBC Materials and Technologies proposes a completely new approach to diffusion coatings based on its revolutionary Plasma Electrolytic Diffusion (PED) process. IBC Materials, in partnership with the University of Pittsburgh, will use a combination of computational modeling and experimental development to develop novel diffusion coating chemistries with the PED process. Because of the unique diffusion kinetics of the plasma electrolytic processes, it will be possible to deposit non-equilibrium surface chemistries not able to be achieved with conventional processes, achieving a"super-saturated"diffusion layer with a high degree of compositional control and uniformity. BENEFIT: IBC"s advanced Plasma Electrolytic Diffusion (PED) process will solve the current uniformity and standard thermal kinetics limitations that are inherent in conventional coating processes. The ultra-high energies associated with the PED process will allow for far-from equilibrium coating compositions that are not achievable using conventional deposition routes, providing significant improvement in oxidation and hot corrosion performance for high temperature alloys. The non-line-of-sight PED process will provide uniform coatings on complex geometries such as disk rim slots and other critical features. The versatility of the PED process allows for the multi-deposition of elements and flexible morphology control with a low temperature, environmentally benign process.