This University of California, Irvine project will provide researchers with an improved mechanistic understanding of factors governing the performance of high-temperature abradable seals and degradation mechanisms unique to coal-derived syngas and high-hydrogen content (HHC)-based combustion environments. The ultimate goal for the research effort is to develop a knowledge base to support the design of coatings that retain optimal sealing characteristics and are more resistant to wear/attack mechanisms.

The project objectives are to investigate the impact of coal-derived syngas combustion environments on the performance, durability, and degradation of existing abradable coatings used on turbine shroud structures, and assess the potential for alternative materials sets to improve the performance of hot-section abradable seals in integrated gasification combined cycle (IGCC)-based gas turbine power plants. The proposed program will investigate several classes of abradable coatings (including metal and ceramic-based systems currently being utilized) under simulated exposures to syngas-based combustion environments to determine their relevant wear/abrasive recession behavior, hardness, stability under cyclic oxidation, and general thermo-mechanical behavior. The research is focused on correlating the measured thermo-mechanical behavior and controlled abrasive wear with the intrinsic properties of the multilayer coatings, process-controlled microstructural features, and service environment exposures.