Residual Stress and Stability of Thermal Barrier Coatings during Cyclic Thermal Loading

摘要

The residual stress accumulation of thermal barrier coatings (TBC) during thermal cycling has been simulated by thermal elastic-plastic finite element method. Stability process of thermal barrier coatings during thermal cycling is studied by Melan's static shakedown theorem considering thermal gradients and thermal expansion misfit. The influences of the interfacial morphology of top coat / bond coat (TC/BC) on residual stress and stability process are analyzed. Thus, the residual stress and stability process are affected remarkably by interfacial topography between TC and BC. Accidented interface cause the sudden change of the interfacial residual stress which is harmful to interface bonding intensity and stabilization. It is useful information for studying of the life and final spallation of TBC system.