大气等离子喷涂环境障涂层镀铝表面改性-中国材料进展

文章信息/Info

Title:: Al-modified environmental barrier coating prepared by atmospheric plasma spray

作者:: 张小锋1; 周克崧1; 刘敏1; 李洪1; 阳海棠2; 牛少鹏1; 邓春明1; 邓畅光1; 1. 现代材料表面工程技术国家工程实验室及广东省现代表面工程技术重点实验室，广东省新材料研究所广州 510650； 2. 航空航天学院，中南大学长沙410083）

Author(s):: ZHANG Xiaofeng1; ZHOU Kesong1; LIU Min1; LI Hong1; YANG Haitang2; NIU Shaopeng1; DENG Chunming1; DENG Changguang1; 1. National Engineering Laboratory for Modern Materials Surface Engineering Technology & The Key Lab of Guangdong for Modern Surface Engineering Technology，Guangdong Institute of New Materials, Guangzhou 510650, China; 2. Hunan Laboratory of Advanced Fibers and Composites, Central South University, Changsha 410083, China

Keywords:: EBCS; atmospheric plasma spray; Al-modification; water-oxygen corrosion; CMAS corrosion; thermal cycle

摘要:: 陶瓷基复合材料(CMC)由于具有较低的密度(高温合金的1/3～1/4)、较高的服役温度(比高温合金高200～240 ℃)以及良好的结构强度(高温合金的2倍)，已成为未来大推重比航空发动机热端部件的首选材料。发动机服役过程中，热端部件完全暴露于空气气氛中，服役环境恶劣，以SiC/SiC为代表的CMC部件直接面临着腐蚀、烧蚀、冲刷等问题，因此急需开展一类高性能CMC热防护涂层即环境障涂层（EBCs）的研究。通过大气等离子喷涂在SiC/SiC CMC基体表面制备硅/莫来石/硅酸镱（Yb2SiO5）三层结构EBCs。为提高EBCs服役性能，对涂层样品进行镀Al表面改性即采用磁控溅射技术在涂层表面镀Al全包覆，然后对其进行真空热处理。在高温低真空下，涂层表面Al膜发生熔融并在毛细管力的作用下往多孔涂层内部渗透并与Yb2SiO5发生原位反应，在涂层表面形成一层致密αAl2O3层。对喷涂态及镀Al表面改性涂层进行典型模拟服役环境性能对比实验，发现镀Al表面改性EBCs具有较好的抗高温水氧及耐CMAS(CaO-MgO-Al2O3-SiO2)腐蚀性能。另外，通过实验观察，原位形成的α-Al2O3致密层对涂层的热循环性能无明显影响。

Abstract:: The ceramic matrix composite (CMC) material with low density (1/3～1/4 of superalloy) and high operation temperature (200～240℃>superalloy), it has been became a preferred material in future for high thrust-weight ratio aero-engine. In service operation, hot components are completely exposed to atmospheric environment. Representative CMC component of SiC/SiC faces serious operation conditions such as corrosion, ablation, erosion, etc. Therefore, it is urgent to develop a high performance protective coating for CMC component (i.e. environment barrier coatings, EBCs). In this investigation, three-layer-structured EBCs (Si/mullite/Yb2SiO5) were prepared by atmospheric plasma spray. For improving the performances of EBCs, the EBCs samples were deposited with Al film and carried out with vacuum heat treatment. Through in-situ synthesis between Al and Yb2SiO5 at high temperature in vacuum, a dense α-Al2O3 overlay can be formed. The results show that the Al-modified EBCs samples have better oxygen-water, CMAS corrosion resistance than the as-sprayed EBCs. Besides, Al-modification for EBCs have no apparent negative affection on thermal cycle performance compared with the as-sprayed EBCs.