Thermal fatigue behavior of thermal barrier coatings with the MCrAlY bond coats by cold spraying and low-pressure plasma spraying

Abstract

The thermal fatigue behavior of thermal barrier coatings (TBCs) with the NiCoCrAlTaY bond coats deposited by cold spraying and low-pressure plasma spraying (LPPS) was examined through thermal cyclic test. The TBCs were subjected to the pre-oxidation before the test in an Ar atmosphere. The results show that a more uniform TGO in both thickness and composition forms on the cold-sprayed bond coat than that deposited by LPPS. The TBCs with the cold-sprayed bond coat exhibit a longer thermal cyclic lifetime than that with the LPPS bond coat. The differences in oxidation behavior and thermal cyclic behavior between two TBCs were discussed based on the evident difference in the surface morphology of two MCrAlY bond coats deposited by cold spraying and LPPS.