碳化硅陶瓷基复合材料环境障涂层研究进展

Research Progress in Environmental Barrier Coatings of SiC Ceramic Matrix Composites

碳化硅陶瓷基复合材料(CMC-SiC)因具有低密度、抗氧化、耐高温等优点,成为下一代先进航空发动机热端结构部件的潜在材料。然而,CMC-SiC在燃气环境中面临着严重的腐蚀问题,需要在环境障涂层(environmental barrier coatings,EBCs)的保护下才能实现长时应用。本文介绍了EBCs的选材要求、发展历程、涂层制备工艺、涂层考核技术以及表征手段,综述了EBCs体系在服役过程中存在挥发速率高、使用温度低等问题以及在制备过程中存在涂层晶化率低、致密度低等问题,指出了今后国内在EBCs材料优选、制备工艺、评价方法以及考核平台的研究目标与发展方向。

SiC matrix ceramic composites(CMC-SiC)are considered as the potential primary structural materials in advanced gas turbines because of their low density,good oxidation resistance and high-temperature strength.However,CMC-SiC suffers from serious degradation in the gas environments.With the protection of environmental barrier coatings(EBCs),CMC-SiC composites can be possibly applied as hot components with long lifetime in the aero-engine.The materials selection requirements,development history,preparation process,assessment technologies and characterization methods of EBCs materials system were introduced in this paper.The open problems of EBCs materials system such as high volatile rate,low operating temperature during service and low crystalline fraction,low density of the coatings during the preparation process were summarized and analyzed.The research goal and development direction in the EBCs system optimization,fabrication process development and evaluation and assessment platform were put forward.