Study on the effects of impurities on the properties of YSZ thermal barrier coatings

In recent years, researchers pay close attention to the development of high purity thermal barrier coatings. At the same time, according to the influence of other oxides in YSZ structure material on its performance, it is found that besides SiO2 and Al2O3, such as Fe2O3, TiO2 and so on, they also have some influence on the performance of YSZ. The mass percent content of SiO2, Al2O3 and Fe2O3 respectively changes from less than 0.01% to 1% when the properties of YSZ coating change along with it. This research also discusses the influence mechanism of several oxides on the performance of YSZ coating, and puts forward the suggestions on control the impurity content in the preparation of YSZ material. In this paper, YSZ spraying materials with different mass percentages of SiO2, Al2O3 and Fe2O3 were designed, and coatings were prepared by APS. The microstructure, phase structure, thermal shock resistance and sintering shrinkage of the above coatings were investigated. The results show that the porosity of YSZ coating decreases and the sintering shrinkage increases with the increase of impurity oxide content, and the coating is more prone to thermal shock failure.