Simulation of Interfacial Stress in TBCs with Oxidation-Resistance Interlayer under Thermal Loading

Plasma-sprayed Al₂O₃ interlayer was prefabricated between the bondcoat and topcoat in thermal barrier coatings. It can prevent oxygen penetration through the interconnected porosity in the topcoat, so that the thermally grown oxide (TGO) growth and the failure can be suppressed. But, prefabricated Al₂O₃ interlayer will result in interfacial stress redistributing. The paper, basing on three-dimensional shape of thermal barrier coatings, using elastic sphere model, considering topcoat, interlayer, TGO and bondcoat, have developed a four-concentric-sphere model of three-dimensional, and produced the relevant analytical model. Furthermore, to verify the results by FEM. In this paper, the analysis of anti-oxidation layer for the concave and convex asperity, indicate that the method can simulate the effect of interlayer on the interfacial microstructurepsilas stress distributing of thermal barrier coatings.