摘要
The commonly-employed material for thermal barrier coatings(TBCs)is 7 wt.%Y2O3 ZrO2(7YSZ),generally deposited by electron beam-physical vapor deposition(EB-PVD).Due to the increasing demand for higher operating temperature in aero-derivative gas turbines,a lot of effort has been made to prevent the premature failure of columnar 7YSZ TBCs,which is induced by the microstructure degradation,sintering and spallation after the deposition of infiltrated siliceous mineral(consisting of calcium magnesium aluminum silicate(CaO MgO Al2O3 SiO2,i.e.,CMAS)).A new method called Al-modification for columnar 7YSZ TBCs against CMAS corrosion was present.The Al film was magnetron-sputtered on the surface of the columnar 7YSZ TBCs,followed by performing vacuum heat treatment of the Al-deposited TBCs.During the heat treatment,the molten Al reacted with ZrO2 to formα-Al2O3 overlay that effectively hindered CMAS infiltration.Moreover,the Al film could evaporate and re-nucleate,leading to the generation of Al2O3 nanowires,which further restrained the moving of molten CMAS.
7YSZ(7wt.%Y2O3 ZrO2)作为热障涂层使用最广的材料,其主要制备方法包括电子束-物理气相沉积(EB-PVD)。随着涡轮前进口温度的逐步提高,CMAS(CaO MgO Al2O3 SiO2)熔盐腐蚀等因素逐渐成为影响柱状结构EB-PVD 7YSZ热障涂层服役寿命的关键因素。本文作者提出一种镀铝表面改性技术,即在柱状涂层表面采用磁控溅射技术制备一层Al膜,然后施加真空热处理工艺。一方面,Al和7YSZ涂层发生原位反应形成α-Al2O3层,抑制CMAS熔盐高温渗透;另一方面,在真空热处理过程中Al膜在高温下发生蒸发和形核,最终在7YSZ热障涂层表面形成氧化铝纳米线,抑制高温下熔融CMAS流动。
基金
Project(2017YFB0306100) supported by the National Key Research&Development Plan of China
Projects(51801034,51771059) supported by the National Natural Science Foundation of China
Projects(2018GDASCX-0949,2018GDASCX-0950,2017GDASCX-0111) supported by the Guangdong Academy of Sciences,China
Projects(2017B090916002,2017A070701027) supported by the Guangdong Technical Research Program,China
Projects(2016A030312015,2017A030310315) supported by the Natural Science Foundation of Guangdong Province,China
Projects(201605131008557,201707010385) supported by the Technical Research Program of Guangzhou City,China
