Service Temperature Measurement and Thermal Insulation Mechanism of Thermal Barrier Coatings

Abstract

Thermal barrier coatings (TBC) are used for thermal protection of aero-engine turbine blade surface, which mainly consist of bond coatings and ceramic coatings. Accurate measurement of temperature distribution on the surface of ceramic coating and bond coating/ceramic coating interface is of great significance for guiding the design and preparation of high-heat insulation structure of coating. At present, the surface temperature can be measured by the existing non-contact and contact temperature measurement technologies, and the interface temperature can be measured by the contact temperature measurement technology. In this paper, three kinds of technologies applied to the turbine blade surface temperature measurement of aeroengine were introduced. Among them, the thermal barrier coating surface temperature measurement technologies included infrared radiation, fluorescence, crystal and optical fiber, which based on the optical principle, and temperature indicating paint temperature measurement, which based on thermotropic principle. Moreover, the temperature measurement technologies of landfill thermocouple and film thermocouple based on thermoelectric principle were applied to the temperature measurements of thermal barrier coating interface, and their principle, advantages and limitations were introduced. Furthermore, the thermal insulation mechanism and performance optimization of thermal barrier coating were introduced, and the temperature measurement technology of thermal barrier coating surface or interface and the direction of coating structure designs were prospected.

Keywords

• temperature measurement method; heat insulation mechanism; thermal barrier coating; thermocouple