Research Progress of High-entropy Ceramics Materials for Thermal Barrier Coatings

The thermal barrier coating is a surface technology applied to the hot end components of a turbine engine and has a thermal insulation effect. With the continuous development of aerospace technology,the thrust-weight ratio of turbine engines increases gradually. The increasing inlet temperature of the turbine and the worse use environment put forward higher requirements for thermal barrier coating ceramic materials. In recent years,a variety of ceramics have been considered to have potential applications in thermal barrier coatings. High entropy ceramics have attracted much attention due to their excellent thermodynamic properties and excellent thermal insulation. On this basis,three criteria for high-entropy ceramic composition design were reviewed,including atomic size criterion,lattice parameter criterion,and entropy criterion. The limitations of different criteria in actual ceramic composition design were summarized. The synthesis methods of high-entropy ceramics were summarized,and the solid-state reaction,sol-gel,co-precipitation,and solution combustion methods were definitely introduced,and the advantages and disadvantages of different preparation methods for synthesizing ceramic powders were compared. Three structures of high entropy ceramics for thermal barrier coatings were summarized,including pyrochlore / fluorite structure,monazite structure,and perovskite structure. The performance characteristics of high entropy ceramics,including thermal insulation,thermodynamic properties,corrosion resistance,and chemical compatibility were reviewed,and the mechanism of multi-component doping to optimize the performance of ceramics was analyzed. Finally,the development direction of high entropy ceramics in the application of thermal barrier coatings had prospected. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.