Evaluating the Sand Resistance of Tailored Thermal Barrier Coatings for Gas Turbine Engines

摘要

US military vertical takeoff and landing (VTOL) aircraft operating in austere, particleladen environments have experienced significant knockdown on engine life, which lead to higher sustainment costs, and catastrophic engine failures, which have resulted in the loss of aircraft and lives. This is directly related to the intake of particulates, such as sand, fly ash, volcanic ash, salt, and dust, into the hot section of modern gas turbine engines. While the vast majority of small particulates melt, some larger particles can impact and erode the surfaces of thermal barrier coatings (TBCs). These impact points can serve as nucleation sites for the impingement, adhesion, and solidification of the molten contaminants into a glassy coating of calcia-magnesia-alumino-silicates (CMAS). This paper will summarize the bench-level testing efforts of an Army-Navy-NASA team to mitigate particulate-damage mechanisms through the development of unique, tailored thermal barrier coatings.