热障涂层是提升航空发动机服役温度最切实可行的方案。传统氧化钇稳定氧化锆(YSZ)涂层在超高温下因钇元素扩散及在沉积腐蚀物(CMAS)中富集，导致过饱和t相分解，制约其服役温度和寿命。Ta2O5能降低钇在涂层中的活度及在熔体中的富聚，提高t相稳定性及涂层抗CMAS浸润能力。但钽系涂层与CMAS反应机理尚不明确，且缺乏定量研究。本项目以ZrO2-Ta2O5-Y2O3热障涂层为对象，协同相图测试与CALPHAD方法，建立完整的热力学数据库，获得t相稳定存在的温度、成分范围，构建涂层成分与钇活度的定量关系；结合热、力学性能测定、CMAS浸润实验及微结构表征，开展涂层成分设计、性能测定及固液界面反应调控的系统研究，获得综合性能优异且抗CMAS的涂层；阐明体系表面能与固液界面及涂层成分之间的关联，揭示涂层抗CMAS浸润机制。本项目将为超高温热障涂层抗CMAS浸润的成分设计及机制分析提供指导。

Thermal barrier coatings (TBCs) have been developed as the most feasible resolution to improve the service temperature of aeroengines. Due to the diffusion of yttrium and its enrichment in the deposit corrosion (CMAS), the decomposition of the supersaturated tetragonal phase of traditional yttria-stabilized zirconia (YSZ) TBCs is easy to happen at ultra-high temperature, which restricts the service temperature and life of the coating. The addition of Ta2O5 can effectively reduce the activity of yttrium in the coating and the enrichment in the CMAS, so as to improve the stability of t phase and CMAS-resistant performance of the coating. However, the reaction mechanism between tantalum-base system coating and CMAS is not clear, and the quantitative analysis is lacking. The present work focuses on the thermal barrier coating system of ZrO2-Ta2O5-Y2O3, according to the use of phase diagram experiment and the CALPHAD method, a thermodynamic database of the system will be established to obtained the temperature and composition region of the t phase as well as the quantitative relationship of Ta2O5 content with the activity of yttrium. Combining the thermal and mechanical properties measurement, CMAS infiltration experiment and microstructure characterization, a systematic research will be carried out on the design of the coating composition, the preparation of the coating, the determination of properties and the regulation of solid-liquid interface, to obtain the coating composition with excellent comprehensive performance as well as CMAS resistant. The mechanism of CMAS-resistant will be discussed by analyzing the relationship between the surface energy of the system and the solid-liquid interface and the coating composition. This project is expected to provide an important guidance for the design of tantalum system thermal barrier coatings for CMAS wetting and infiltrating resistance.