面向工程设计的热障涂层寿命预测方法

A methodology of life prediction for thermal barrier coatings was developed to meet the engineering design requirement of turbine blades with coatings. According to the loading feature of thermal barrier coatings,a simplified mechanical model was adopted to calculate the critical behavior of each layer efficiently. The interfacial damage evolution generated in the coatings was measured by the spalling-resistance tests on the simulated specimens with thermal barrier coatings after undergoing high-temperature long-term oxidation and thermal fatigue. On this basis,the total damage in the coatings was decomposed and a damage model considering the coupling of oxidatively induced and mechanically induced damages was proposed to improve the prediction accuracy of damage and spallation life. Lastly, based on the theoretical models,a software tool for damage analysis and life prediction of thermal barrier coatings, which can be integrated in the existing design process of components, was developed and verified by the instance of turbine blade. The results showed that the above-mentioned method predicted the evolution of damage generated in thermal barrier coatings with an error of ±10%.