EB-PVD热障涂层TGO三维结构分析  

Three-dimensional structure analysis of TGO in EB-PVD thermal barrier coatings

作　　者：敖波[1] 钟建兰 古玉祺 Ao Bo;Zhong Jianlan;Gu Yuqi(Key Laboratory of Nondestructive Testing,Ministry of Education,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学无损检测技术教育部重点实验室

出　　处：《仪器仪表学报》2018年第8期136-142,共7页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(51561025)项目资助

摘　　要：热生长氧化物（TGO）的厚度及形貌是影响热障涂层热应力的关键因素。首先开展了电子束物理气相沉积（EB-PVD）热障涂层1 050℃恒温氧化实验,采用聚焦离子束-扫描电子显微镜（FIB-SEM）实现了EB-PVD热障涂层三维成像,获得了576幅热障涂层高温氧化48 h后的SEM图像;其次,通过EB-PVD热障涂层三维结构的分割与提取,得到了真实TGO三维结构和柱间孔隙三维分布,实现了TGO层的厚度测量;最后建立了基于TGO三维结构和柱间孔隙三维分布的EB-PVD热障涂层有限元热应力分析模型,分析了真实TGO三维结构和柱间孔隙三维分布对EB-PVD热障涂层热应力的影响。结果表明,TGO层的平均厚度为2.37μm,有限元模型中最大拉应力为403 MPa,最大压应力为-282 MPa,最大拉应力与最大压应力均出现在陶瓷层中的柱间孔隙处。The thickness and morphology of thermally grown oxide（ TGO） are key factors which affect the thermal stress of thermal barrier coatings（ TBCs）. Firstly,an isothermal oxidation experiment is performed at 1050 ℃ for TBCs generated by electron beam physical vapor deposition（ EB-PVD）. The three-dimensional（ 3 D） imaging of EB-PVD thermal barrier coatings is realized by the focused ion beam-scanning electron microscopy（ FIB-SEM）,and 576 SEM images of TBCs after high temperature oxidation for48 h are obtained. Secondly,the real 3 D structure of TGO and 3 D distribution of inter-column pores are obtained based on the 3 D structure segmentation and the extraction of EB-PVD thermal barrier coatings. The thickness of the TGO layer is measured.Finally,a finite element thermal stress analysis model of EB-PVD thermal barrier coatings based on the 3 D structure of TGO and3 D distribution of inter-column pores is established. The influence of the real 3 D structure of TGO and 3 D distribution of intercolumn pores on the thermal stress of EB-PVD thermal barrier coatings is analyzed. Experimental results indicate that the average thickness of TGO layer is 2. 37 μm,the maximum tensile stress in the finite element model is 403 MPa,and the maximum compressive stress is-282 MPa,both the maximum tensile stress and the maximum compressive stress appeared in the intercolumn pores in the top coat.

关 键 词：电子束物理气相沉积 热生长氧化物 聚焦离子束-扫描电子显微镜 三维结构 

分 类 号：V232.4[航空宇航科学与技术—航空宇航推进理论与工程] TH142.2[一般工业技术—材料科学与工程]