文献类型：期刊文献

英文题名：Quantitative Determination of Porosity in Thermal Barrier Coatings Using Terahertz Reflectance Spectrum: Case Study of Atmospheric-Plasma-Sprayed YSZ Coatings

作者：Ye, Dongdong[1];Wang, Weize[1];Zhou, Haiting[2];Li, Yuanjun[1];Fang, Huanjie[1];Huang, Jibo[1];Gong, Hanhong[3];Li, Zhen[3]

机构：[1]East China Univ Sci & Technol, Key Lab Safety Sci Pressurized Syst, Shanghai 200237, Peoples R China;[2]China Jiliang Univ, Dept Qual & Safety Engn, Hangzhou 310018, Peoples R China;[3]Univ Shanghai Sci & Technol, Shanghai Key Lab Modern Opt Syst, Shanghai 200093, Peoples R China

年份：2020

卷号：10

期号：4

起止页码：383

外文期刊名：IEEE TRANSACTIONS ON TERAHERTZ SCIENCE AND TECHNOLOGY

收录：;EI(收录号：20203709152223);WOS:【SCI-EXPANDED(收录号:WOS:000545420700007)】；

基金：This work was supported in part by the National Nature Science Foundation of China under Grant 51775189 and in part by the Shanghai Key Laboratory of Modern Optical Systems and University of Shanghai for Science and Technology.

语种：英文

外文关键词：Coatings; Reflectivity; Ceramics; Microstructure; Permittivity; Scanning electron microscopy; Reflection; Effective medium theory (EMT); porosity; terahertz (THz) reflectance spectrum; thermal barrier coatings (TBCs)

摘要：Microstructures of yttria-stabilized zirconia (YSZ) atmospheric-plasma-sprayed (APS) thermal barrier coatings (TBCs) and their terahertz dielectric properties were investigated to quantitatively determine porosities by effective medium theory (EMT). Various samples with different porosities ranged from 9.15% to 21.58% were prepared by different particle size powders and spray power. Both the theoretical and experimental results showed that the interferential oscillation period of reflectance spectra of APS YSZ TBCs samples depends on optical thickness of ceramic coatings, and optical thickness depends on permittivity for known geometric thickness. The real part of permittivity epsilon ' decreased as the porosity increased, the depolarization factor zeta of APS YSZ TBCs pores, which was estimated by comparing the experimental value with the simulated value obtained by the Maxwell-Garnett EMT model and Bruggeman EMT model, approached to a fixed value, owing to the typical lamellar structure of APS-TBCs, and was 0.7 and 0.6 in respective models. Samples of 185-459 mu m thickness verified that the technique varied from scanning electron microscope statistics results by <15%. Finally, a novel, convenient, online, nondestructive, and noncontact porosity evaluation method is proposed that can potentially be utilized on the health monitoring of TBCs in gas turbine blades.