烧结诱发的 EB-PVD 热障涂层微结构与弹性模量演化研究

The microstructure and elastic modulus evolution of electron beam-physical vapor deposition (EB-PVD) thermal barrier coating were studied. The sintering test of EB-PVD thermal barrier coating at 1 150 ℃ was carried out，and the microstructure of the test piece after sintering was observed by scanning electron microscope (SEM)， and the evolution of columnar crystal gap in ceramic layer was obtained. The elastic modulus of ceramic layer was measured by nanoindenter. The results showed that the elastic modulus of ceramic layer increased rapidly at the initial stage of sintering and then became stable. In order to relate the elastic modulus of ceramic layer with the micro-structure evolution，a simplified cylindrical crystal model of ceramic layer was established based on the prepared microstructure，and the evolution law of the elastic modulus was obtained by using the sintering model based on the microstructure evolution. The results showed that the microstructure evolution induced by sintering led to the change of elastic modulus of ceramic layer. The sintering model based on the microstructure evolution can accurately predict the evolution law of elastic modulus with sintering time，and the error between the measured value and the calculated value was less than ±20%.