AlPO_4环境障碍涂层材料水氧腐蚀性能研究

Corrosion Behavior of AlPO_4 as Environmental Barrier Coating in Water Vapor Enviroment

采用溶胶-凝胶法合成了一种AlPO4环境障碍涂层材料,测定了其热膨胀系数,在1350℃、50vol%H2O/50vol%O2、1.013×105Pa、气体流速0.085cm/s的水氧耦合环境中研究了其抗水氧腐蚀性能,并利用X射线衍射仪、能谱分析仪和扫描电子显微镜分析了材料组成和微观结构.结果表明,AlPO4与C/SiC复合材料热膨胀基本匹配,抗水氧腐蚀性能良好.主要存在的问题是AlPO4分解引起的失重,二氧化硅会加速其分解.

AlPO4 was synthesized by a Sol-Gel method. Its coefficient of thermal expansion （CTE） was measured by dilatometer. Its corrosion behavior was tested in an environment of 50vol% H2O/50vol% O2 with a flow rate of 0. 085cm/s at 1350℃. The phases and composition of the samples were analyzed by X-ray diffraction and Energy Dispersive Spectroscope. The microstructures of AAlPO4 were characterized by Scanning Electron Microscope. The results indicate that the CTE of AAlPO4 matches with that of C/SiC composites and its corrosion resistance is much better than that of SiC. However, the decomposition of AAlPO4 at high temper- atures is the main problem in the water vapor enviroment, which will be accelerated in combination with silica.