Fatigue Testing of Ceramic Thermal Barrier Coatings for Gas Turbine Blades

Time-Economic Lifetime Assessment for High Performance Thermal Barrier Coating Systems

“…The high heating and cooling rates made it possible to simulate the thermo-mechanical fatigue load of an entire flight of a turbine blade in an aero engine within 3 m inutes. A detailed description of the testing set up is given in [1]. Thermal cycles were between 100 a nd 1000°C, the mechanical load was tensile and in phase.…”

On TGO creep and the initiation of a class of fatigue cracks in thermal barrier coatings

“…The experiments and the results have been reported in previous studies [6][7][8][9]. For clarity of the discussion that follows, we will here give a brief outline of the test method and review selected results pertaining to the current work.…”

“…This test set-up allows testing and evaluation of TBCs by simulating the conditions in an aircraft engine in an accelerated manner [9]. The loading sequence consists of heating to high temperature, hold at high temperature, and cool to low temperature.…”

Evolution of surface morphology of thermo-mechanically cycled NiCoCrAlY bond coats

“…The power output of the lamps was controlled by the outer surface temperature of the specimen, which was measured with a thin wire thermocouple (Ø 0.3 mm, Type S) enlacing the specimen. The maximum temperature set-point value was 1000 • C and the minimum set-point value about 100 • C. This temperature range corresponds to typical field conditions for thermal barrier sys tems [1,[13][14][15]. During the heating sequence of the thermal cycle (compare Fig.…”

“…The transient temperature differences during heating and cooling could not be measured due to the thermal inertia of the sheet thermocouples. The tests were force con trolled with respect to an axial tensile force, representing the [15]. Before the tests, the TBC coated specimens were indented with a Rockwell brale C indenter generating a local delamina tion and spallation of the TBC.…”