Development of Protective Coatings for Single-Crystal Turbine Blades

73009S03-I Turbine blades in coal-derived syngas systems are subject to oxidation and corrosion from high steam temperature and pressure. Although thermal barrier coatings (TBCs) have been developed to address these problems, further improvements are required, especially a prime-reliant design and a better coating architecture. This project will develop and characterize a prime-reliant TBC system, with a denser NiCoCrAlY bond layer and a defect-free oxide sublayer, using a novel Filtered Cathodic Arc technology. In Phase I, a dense, defect-free NiCoCrAlY bond coat will be deposited on single-crystal substrates, using a novel, enhanced filtered cathodic arc deposition technique. Then, two sublayers will be deposited: a stable alpha alumina sublayer and an Yttrium Aluminum Garnet (YAG) sublayer. The samples will be characterized with and without the top TBC layer. Commercial Applications and Other Benefits as described by awardee: In addition to the application for turbine blades of coal-derived syngas systems, the TBC technology could be extended to the protection of other gas turbine engine components, including aerospace, marine, and land-based systems. The market for TBCs is expected to increase at a rate of about 10% per year as these coatings find increased applications in coal-derived syngas and gas turbine markets. The development is important for the power industry, land-based turbines, power plants, and other utility companies.