Effect of microstructure and environmental conditions on the dielectric properties of plasma sprayed Al2O3 insulating coatings

doi:10.1016/j.ceramint.2023.10.267

IMR OpenIR

	Effect of microstructure and environmental conditions on the dielectric properties of plasma sprayed Al2O3 insulating coatings
	Han, Botao 1,2; Li, Ning 1,2; Che, Yanhao 1,2; Wang, Jiqiang 1; Xiong, Tianying 1; Cui, Xinyu 1
通讯作者	Cui, Xinyu(xycui@imr.ac.cn)
	2024
发表期刊	CERAMICS INTERNATIONAL
ISSN	0272-8842
卷号	50 期号:1 页码:1713-1724
摘要	The effect mechanism of microstructure and environmental conditions on the dielectric properties of plasmasprayed Al2O3 insulating coatings was systematically investigated in this study. Two kinds of Al2O3 powders with different particle sizes were used to deposit the coatings under the same spraying parameters. The microstructures of the coatings (including porosity, pore size, crack density, and phase composition) were analyzed using scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), and X-ray diffraction (XRD). The dielectric properties (including breakdown strength, resistivity, dielectric constant, dielectric loss, and complex impedance) were characterized by a two-electrode measurement cell. The results indicated that the coating deposited with the larger-sized powder (D50=45.8 mu m) exhibited higher porosity, alpha-Al2O3 content, and connected crack density, than the coating with the other kinder of powder (D50=22 mu m). The DC and AC breakdown strengths were found to be related to the porosity of the coatings and the partial discharge in the pores results in the eventual breakdown. The resistivity of the coatings decreased significantly with increasing humidity due to the moisture adsorbed on the pores and cracks. In high-humidity environments, the water molecule enhanced space charge polarization (WESCP), as the main polarization mode, contributed to the dramatic increase of the dielectric constant and dielectric loss. Moreover, the complex impedance and phase angle showed frequency-dependent changes in different environments, suggesting a combined effect of humidity and temperature on the polarization and conductance of coatings. The obtained results of this study could pave the way for the design and application of high-performance plasma-sprayed insulating coatings.
关键词	Breakdown strength Resistivity Complex impedance
资助者	National Key Research and Development Program of China
DOI	10.1016/j.ceramint.2023.10.267
收录类别	SCI
语种	英语
资助项目	National Key Research and Development Program of China[2020YFB2007803]
WOS研究方向	Materials Science
WOS类目	Materials Science, Ceramics
WOS记录号	WOS:001128609100001
出版者	ELSEVIER SCI LTD
引用统计	被引频次：2[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/183114
专题	中国科学院金属研究所
通讯作者	Cui, Xinyu
作者单位	1.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China 2.Univ Sci & Technol China, Sch Mat Sci & Engn, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Han, Botao,Li, Ning,Che, Yanhao,et al. Effect of microstructure and environmental conditions on the dielectric properties of plasma sprayed Al2O3 insulating coatings[J]. CERAMICS INTERNATIONAL,2024,50(1):1713-1724.
APA	Han, Botao,Li, Ning,Che, Yanhao,Wang, Jiqiang,Xiong, Tianying,&Cui, Xinyu.(2024).Effect of microstructure and environmental conditions on the dielectric properties of plasma sprayed Al2O3 insulating coatings.CERAMICS INTERNATIONAL,50(1),1713-1724.
MLA	Han, Botao,et al."Effect of microstructure and environmental conditions on the dielectric properties of plasma sprayed Al2O3 insulating coatings".CERAMICS INTERNATIONAL 50.1(2024):1713-1724.