Abstract
In this study, a method for predicting the thermal shock life of coatings is proposed, and a model for predicting the thermal shock life of coatings based on high temperature thermal shock life test and three-dimensional heat transfer analysis is established. Firstly, the thermal shock life of coatings at different cooling and heating cycle temperatures is obtained through a designed thermal shock life testing device for silicide coatings at a wide-temperature range from 500℃ to 3000℃. Secondly, the actual thickness of the coating and the continuous oxidation in the thermal shock life test are taken into consideration. Based on the finite element analysis method, the three-dimensional heat transfer analysis for coatings with different oxidation thickness is carried out to obtain the average value of the maximum thermal stress range on the surface of the coating. Last, the least square method is used to process the data of the life prediction model. Then the parameters of the life prediction model are obtained based on the thermal shock life test of the coating and the average value of the maximum thermal stress range on the coating surface. It turns out that the predicted results of the thermal shock life prediction model established in this study are in good agreement with the tested results. Besides, the relative error is less than 6%. Therefore, the life prediction method proposed in this study can be used to predict the thermal shock life of silicide coatings. What's more, the research work in this study can also provide a theoretical basis for the life prediction of coating materials.