Properties of the BaTiO₃ coating prepared by supersonic plasma spraying

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• 作者：Zhiguo Xing ; Haidou Wang ; Lina Zhu ; Xinyuan Zhou ; Yanfei Huang
• 关键词：Ceramics ; Coating materials ; Mechanical properties ; Phase transitions ; Piezoelectricity
• 刊名：Journal of Alloys and Compounds
• 出版年：2014
• 出版时间：5 January, 2014
• 年：2014
• 卷：582
• 期：Complete
• 页码：246-252
• 全文大小：2383 K

文摘

Plasma spraying technique enables to create layers with thickness in a millimeter range adhering to various substrates. The supersonic plasma spraying can spray the powders at acoustic speed, which can increase the coating density and improve the bond strength between the coating and substrate. In the present study, a BaTiO₃ coating with good physical property and preliminary piezoelectric index was prepared by supersonic plasma spraying. The spraying process was carried out by a direct current gas-stabilized plasma gun, which was manufactured by the Science and Technology on Remanufacturing Laboratory. It was found that the high temperature could make the BaTiO₃ possess the piezoelectric nature. The surface of the BaTiO₃ coating was smooth and dense, and the mechanical bond existed between the substrate and the coating. The average bond strength and microhardness were 47.4 MPa and 650 HV_0.1, respectively. The BaTiO₃ phase changed from cubic to tetragonal phase in the course of supersonic plasma flame flow. About 25 % (mol) BaTiO₃ was decomposed into BaO and TiO₂. The decomposition and original defects of the spraying coating could decrease its piezoelectric activity. The piezoelectric performance of the BaTiO₃ coating was lower than that of the sintering ceramic, but obvious piezoelectricity existed in the sprayed BaTiO₃ coating.