不同厚度8YSZ热障涂层的结构及性能表征  

Structure and Properties of 8YSZ Thermal Barrier Coatings with Different Thickness

作　　者：赵荻 安宇龙[1,2] 赵晓琴 刘光[3] 陈杰[3] 周惠娣[1,2] ZHAO Di;AN Yu-long;ZHAO Xiao-qin;LIU Guang;CHEN Jie;ZHOU Hui-di(State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730000,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Ningbo Branch of Chinese Academy of Ordnance Science,Ningbo 315103,China)

机构地区：[1]中国科学院兰州化学物理研究所固体润滑国家重点试验室,兰州730000 [2]中国科学院大学材料与光电研究中心,北京100049 [3]中国兵器科学研究院宁波分院,浙江宁波315103

出　　处：《表面技术》2020年第1期276-284,共9页Surface Technology

基　　金：中国科学院青年促进会(2014378);中国科学院“西部之光”预先研究项目(41423030303)~~

摘　　要：目的探究厚度变化对8YSZ热障涂层结构、力学性能以及抗热震性能的影响。方法通过超音速火焰喷涂技术(HVOF)和大气等离子喷涂技术(APS)分别制备了NiCoCrAlTaY粘结层和厚度为500μm、1.0 mm、1.5 mm的8YSZ陶瓷涂层,采用扫描电子显微镜(SEM)、光学显微镜和X射线衍射仪(XRD)对喷涂粉末和涂层的形貌、物相进行了表征,借助显微硬度计和万能材料试验机分别考察了涂层的硬度和结合强度,最后采用水淬法对涂层的抗热震性能进行了测试。结果不同厚度的8YSZ涂层均由非平衡的四方相(t′-YSZ)组成,且断面呈现出明显的层状结构。随着厚度的增加,涂层中逐渐产生了明显的网状纵向裂纹和边缘界面裂纹。涂层的表面和截面显微硬度都不随厚度的增加而发生显著变化,并且所制备的涂层在整个截面上的显微硬度都比较均匀。涂层的结合强度随着涂层厚度的增加而显著降低。热震试验过程中,三种厚度涂层皆以界面开裂的形式失效,且厚度越大的涂层热震寿命越短。结论8YSZ热障涂层的厚度变化对其微观形貌、结合强度以及抗热震性能皆有显著影响,而对涂层的物相组成以及显微硬度无明显影响。The work aims to study the effects of thickness variation on the structure,mechanical properties and thermal shock resistance of 8YSZ thermal barrier coatings.NiCoCrAlTaY bond coatings and 8YSZ ceramic coatings with thickness of 500μm,1.0 mm and 1.5 mm were prepared by high velocity oxy-fuel spraying technology and atmospheric plasma spraying technology respectively.The morphologies and phase compositions of the sprayed powders and coatings were characterized by scanning electron microscope(SEM),optical microscope and X-ray diffraction(XRD).The hardness and bonding strength of the coatings were measured by micro-hardness tester and universal material testing machine.Finally,the thermal shock resistance of the coatings was tested by water quenching method.The 8YSZ coatings with different thickness basically consisted of non-equilibrium tetragonal phase(t′-YSZ)and exhibited a distinct layered structure on the fracture surface.As the thickness increased,obvious reticular longitudinal cracks and edge interface cracks gradually appeared in the coating.The micro-hardness of surface and cross section had no obvious change with increasing thickness.Meanwhile,the micro-hardness of prepared coating was uniform over the entire section of the coatings.The bonding strength decreased significantly as the thickness of the coating increased.In the thermal shock tests,all these three coatings failed in the form of interface cracking.Besides,the thermal shock lifetime of the coatings became shorter as the thickness increased.The thickness variation has important effects on the microstructure,bonding strength and thermal shock resistance of the 8YSZ thermal barrier coatings while phase composition and micro-hardness are independent on thickness.

关 键 词：8YSZ 热障涂层 大气等离子喷涂 微观结构 力学性能 抗热震性能 

分 类 号：TG174.442[金属学及工艺—金属表面处理]