Creep Effect on Chemo-Mechanical Coupling Oxidation of Thermal Barrier Coatings

Abstract

In this paper, a chemo-mechanical coupling model considering the creep effect during high-temperature oxidation is developed based on the diffusion-reaction equation. A sinusoidal curve model is developed by the finite element method to simulate the thickness and stress distribution of thermally grown oxide (TGO). The thickness and stress distribution of the TGO in the thermal barrier coating was investigated by changing the coupling effect and creep effect conditions of the model. The results show that with the increase of the coupling coefficient, the thickness of TGO gradually becomes smaller. In the late stage of oxidation, this effect diminishes, and the compressive stress located in the BC/TGO layer groove keeps decreasing, while the tensile stress located in the TC layer groove is the opposite. As the creep rate increases, the maximum tensile/compressive stress in the Y-direction within the thermal insulation coating slowly decreases, and the oxidation rate of the oxide layer moderately decreases. This study is important to find the corresponding solutions and preventive measures for the failure of the thermal barrier coating.