| Abstract Scope |
Most power generation technologies create extreme environments and superalloys in turbines are no exception. Coatings are commonly used, both for the highest temperatures and for lower temperatures where hot corrosion may be a concern. For new superalloys, the challenge is to demonstrate acceptable uncoated oxidation resistance in case the coating fails. Coatings can fail due to the service conditions or manufacturing issues and needing the coating to be prime reliant is a concern. For current coated superalloys, the lifetime limitation in power generation is often interdiffusion rather than oxidation and/or thermal barrier coating spallation. As temperatures increase in the turbine, new issues have arisen such as under platform corrosion and superalloy cracking. As these failures are better understood, there may be opportunities to develop new alloys for these conditions. Research was sponsored by the U. S. Department of Energy, Office of Fossil Energy, Advanced Turbine Program. |