International Conference on Power Engineering-2019 (ICOPE-19)

645 / 2019-02-01 13:09:57

Thermomechanical Fatigue Behavior of Thermal Barrier Coating on Cylindrical Superalloy Tube

Thermomechanical fatigue, thermal barrier coating, superalloy tube

Plenary track > Turbines

Thermomechanical fatigue (TMF) tests of thermal barrier coating on cylindrical superalloy tube were conducted under mechanical strain control with either in phase (IP) or out of phase (OP) in temperature range of 450-850 oC. The bond coat NiCrAlY was prepared by high velocity oxygen fuel (HVOF), and the top coat 7wt% Y2O3-ZrO2 was deposited by air plasma spraying (APS). The testing results showed that the OP TMF life was longer than the IP TMF one under the same mechanical strain amplitude. The observation of the failed specimens revealed that the interface damage and cracking behavior in the two phasing conditions were different. In OP loading, the top coat was cracked and detached from the bond coat while no spallation was found in the IP loading. The experimental results were interpreted based on stress analysis and microscopic analysis.