To understand the thermal insulation and failure problems of the thermal barrier coatings (TBCs) deeply is vital to evaluate the reliability and durability of the TBCs. Actually, experimental methods can not reflect the real case of the TBCs during its fabrication and service process. Finite element modeling (FEM) play an important role in studying these problems. Especially, FEM is very effective in calculating the thermal insulation and the fracture failure problems of the TBCs. In this paper, the research progress of the FEM on the study of the thermal insulation and associated failure problems of the TBCs has been reviewed. Firstly, from the aspect of the investigation of the heat insulation of the TBCs, the thermal analysis via FEM is widely used. The effective thermal conductivity, insulation temperature at different temperatures of the coating surface considering the thermal conduct, convection between the coating and the environment, heat radiation at high temperature and interfacial thermal resistance effect can be calculated by FEM. Secondly, the residual stress which is induced in the process of plasma spraying or caused by the thermal expansion coefficient mismatch between the coating and substrate and the temperature gradient variation under the actual service conditions can be also calculated via FEM. The solution method is based on the thermal–mechanical coupled technique. Thirdly, the failure problems of the TBCs under the actual service conditions can be calculated or simulated via FEM. The basic thought is using the fracture mechanic method. Previous investigation focused on the location of the maximum residual stress and try to find the possible failure positions of the TBCs, and to predict the possible failure modes of the TBCs. It belonged to static analysis. With the development of the FEM techniques, the virtual crack closure technique (VCCT), extended finite element method (XFEM) and cohesive zone model (CZM) have been used to simulate the crack propagation behavior of the TBCs. The failure patterns of the TBCs can be monitored timely and dynamically using these methods and the life prediction of the TBCs under the actual service conditions is expected to be realized eventually.

Modeling of thermal properties and failure of thermal barrier coatings with the use of finite element methods: A review

Determination of interfacial adhesion energies of thermal barrier coatings by compression test combined with a cohesive zone finite element model

A review on failure mechanism of thermal barrier coatings and strategies to extend their lifetime

Damage evolution and rupture time prediction in thermal barrier coatings subjected to cyclic heating and cooling: An acoustic emission method

Microstructure and indentation mechanical properties of plasma sprayed nano-bimodal and conventional ZrO2–8wt%Y2O3 thermal barrier coatings

Effect of Young's modulus evolution on residual stress measurement of thermal barrier coatings by X-ray diffraction

In a thermal barrier coating (TBC) system with cylindrical geometry, the position of coating plays an important role in the distribution of residual stress. In this paper, the residual stress field in three different types of TBCs with cylindrical geometry has been analyzed. The main focus is on the effects of substrate curvature radius, deposition temperature and coating thickness on the residual stress distribution during a deposition process. The results show that the substrate curvature radius significantly affects the distributions of radial and hoop residual stresses, which are in good agreement with experimental measurements by photo-stimulated luminescence piezospectroscopy (Wang et al., Acta Mater., 2009, 57(1):182–195). The maximum radial residual stress locates closely to the coating/thermal grown oxide interface. However, the maximum hoop residual stress lies in the thermal grown oxide layer, which is much more than other three layers and presents a strong stress singularity along the thickness direction.

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Effects of substrate curvature radius, deposition temperature and coating thickness on the residual stress field of cylindrical thermal barrier coatings

By using specially designed freestanding 8 wt.% Y 2 O 3 stabilized ZrO 2 (8YSZ) specimens, a linear relationship is found between the Raman peak shift, Δ ω , and applied uniaxial compressive stress, σ u , i.e., Δ ω  = Π u σ u with Π u being the piezo-spectroscopic coefficient. The linear relationship is used to determine the in-plane residual stress in air plasma-sprayed 8YSZ thermal barrier coatings (TBCs). It is shown that the Π u of the 8YSZ is an exponential function of the thermal cycle N for a given thermal cycling process: Π u  = 37.6exp(−  N /25.9) + 13. Based on these two relationships, the actual residual stress of 8YSZ TBCs determined by the Raman spectroscopy method is quantitatively consistent with that obtained by the X-ray diffraction.

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Effects of piezo-spectroscopic coefficients of 8 wt.% Y2O3 stabilized ZrO2 on residual stress measurement of thermal barrier coatings by Raman spectroscopy

Chungsheng Lu

Papers

Damage evolution and rupture time prediction in thermal barrier coatings subjected to cyclic heating and cooling: An acoustic emission method

Effect of Young's modulus evolution on residual stress measurement of thermal barrier coatings by X-ray diffraction

Effects of substrate curvature radius, deposition temperature and coating thickness on the residual stress field of cylindrical thermal barrier coatings

Effects of piezo-spectroscopic coefficients of 8 wt.% Y2O3 stabilized ZrO2 on residual stress measurement of thermal barrier coatings by Raman spectroscopy