Development Trend of Thermal Barrier Coatings

       With the development of the aviation industry, the thrust-to-weight ratio of the turbine engine is getting higher and higher, and the inlet temperature before the turbine is getting higher and higher. According to the current research history and progress of materials at home and abroad, it is quite difficult to improve the high temperature resistance of turbine blades by increasing the use temperature of materials in a short period of time. A relatively fast and feasible method is to deposit thermal barriers on the turbine blade substrate. Coating to increase its service temperature. The technical research on thermal barrier coatings at home and abroad maintains strong vitality. In the future, the development of thermal barrier coating technology will focus on the following aspects:



(1) Research on a new thermal barrier coating material system suitable for the next generation of supersonic engines, and finding ceramic materials that can replace ZrO2 with better phase stability, lower sintering rate and thermal conductivity is the key.



(2) Optimization research and mechanism research on the materials and preparation process of the existing coating system, including the composition of the MCrAIY bonding layer, the selection of new stable oxides of YSZ ceramics, the improvement and optimization of the coating microstructure, and the improvement and optimization of the coating microstructure. Further research into gradient coating technology to improve the working temperature, service life and thermal insulation properties of the coating.



(3) Research on the thermal insulation effect of thermal barrier coating. The thermal insulation condition of the coating, that is, the temperature gradient, is tested by experimental simulation. Combined with the theory of heat transfer, according to the thermal conductivity of the coating material, the expected thermal insulation effect and the hot end components The working environment can provide the basis for the reasonable design of the coating thickness, and also provide the direction for the improvement of the coating.



(4) Further research on thermal barrier coating life prediction model. If thermal barrier coating is applied to high-risk parts of turbine engine, an engine life prediction system must be established to ensure safety. Therefore, it is necessary to further study the peeling failure mechanism of the thermal barrier coating and the mechanical behavior under service conditions, and establish a relatively complete life prediction model, so as to more accurately evaluate the service life of the coating and provide a reliable guarantee for the practical application of the thermal barrier coating. .



(5) Develop new coating performance testing technology, especially non-destructive testing technology, to accurately characterize the bonding force between the coating and the substrate, the degree of cracking of the coating, and the degree of phase transformation, so as to better control the quality of the coating.