Erosion and Foreign Object Damage of Thermal Barrier Coatings

Thermal barrier coating are perceived as an enabling technology to increase the performance of, improve efficiency within, and lower the emissions from, modern gas turbines. To fully utilise this capability one has to be able to accurately predict the life of these coatings under conditions relevant to gas turbine service. This paper addresses the failure of TBC systems as a result of erosion and foreign object damage. Laboratory studies under controlled conditions using a high temperature gas gun rig are reported and compared to damage observed within engines. Models for erosion and foreign object damage have been reviewed and results from these models compared to observed damage mechanisms. The damage mechanisms that result are related to service parameters including temperature, velocity, particle size, impact angle and TBC material properties.