Study on Oxidation and Thermal Fatigue Properties of Thermal Barrier Coatings on Hot End Components

Abstract

In order to define more accurately the application range of Amperit 415 and Amperit 421, which are commonly used raw materials for the thermal spray adhesive layer, two kinds of thermal barrier coatings (with the same ceramic layer and a different adhesive layer prepared respectively with the two differnt MCrAlY powders mentioned above) were prepared by thermal spraying and vacuum heat treatment. The adhesive layer of the former contained a relatively high contents of Al and Cr, while that of the latter contained a lower contents of Al and Cr as well as the refractory metals of Re and Ta. Subsequently, isothermal oxidation tests at 1 000 ℃ and gradient thermal shock tests were carried out for the two coatings. Additionally, the high - temperature oxidation resistance and thermal fatigue resistance of the two coatings were compared and studied, including the variation of the microstructure and composition of the adhesive layer with oxidation time, the oxidation kinetics curve and corresponding activation energy, and the thermal shock resistance of the two coatings. Results showed that the high - temperature oxidation resistance and thermal fatigue resistance of the two coatings were basically identical, so these two coatings could replace each other for the application in hot end parts under low - hot corrosion and low - erosion conditions.

Keywords

• mcraly| thermal barrier coating| hot end component| thermal spraying| vacuum heat treatment| oxidation kinetics| activation energy| thermal fatigue properties