等离子喷涂-物理气相沉积7YSZ热障涂层高温氧化过程中的阻抗谱分析  

Impedance Spectroscopy Analysis of 7YSZ Thermal Barrier Coatings Prepared by Plasma Spray-Physical Vapor Deposition During the High-temperature Oxidation Process

作　　者：陈文龙 刘敏 张吉阜 邓子谦 肖晓玲 唐维学 CHEN Wenlong;LIU Min;ZHANG Jifu;DENG Ziqian;XIAO Xiaoling;TANG Weixue(Guangdong Industrial Analysis and Testing Center,Guangzhou 510650;Guangdong Institute of New Materials,Guangzhou 510650)

机构地区：[1]广东省工业分析检测中心,广州510650 [2]广东省新材料研究所,广州510650

出　　处：《材料导报》2019年第4期602-606,共5页Materials Reports

基　　金：广东省科学院博士学位人才资助专项(2018GDASCX-0953);广东省科学院科研机构创新能力建设专项(2017GDASCX-0114);广东省科学院公益研究与能力建设专项(2017A070701021)~~

摘　　要：采用等离子喷涂-物理气相沉积(PS-PVD)在预处理的粘结层表面制备了柱状结构的7YSZ热障涂层,并在大气环境下测试了该涂层在950℃的静态高温氧化性能。利用透射电镜(TEM)、扫描电子显微镜(SEM)及能谱仪(EDS)等对热障涂层进行了表征,并采用阻抗谱分析研究了该涂层在高温氧化过程中的结构演变过程。结果表明,7YSZ热障涂层是由二次柱状晶及其纳米间隙、柱状枝晶间孔隙和分布在枝晶上的微纳米固态颗粒组合形成。阻抗分析表明,热生长氧化物(TGO)层在高温氧化150 h后氧空位含量减少,致密度增加。在高温氧化过程中,二次柱状晶的内部结构没有发生明显改变。此外,氧化过程中YSZ层内形成的烧结收缩裂纹是导致YSZ晶界电容值减小、电阻值增加的主要原因。The 7YSZ thermal barrier coatings(TBCs) with columnar structure were prepared on the surface of the pretreated adhesive layer by plasma spray-physical vapor deposition(PS-PVD) and their static high-temperature oxidation performance was tested at 950 ℃ in the atmosphere.Besides,The TBCs were characterized through transmission electron microscope(TEM),scanning electron microscope(SEM) and energy dispersive spectrometer(EDS),and the structure evolution of the coatings during the oxidation process at high temperature was further investigated by impedance spectroscopy.The results indicated that the 7YSZ TBCs were composed of secondary columnar grains and their nano-gaps,columnar interdendritic pores and micro-nano solid particles distributed on the columnar dendrites.Impedance analysis showed that after high temperature oxidation for 150 h,the oxygen vacancies content of TGO layer decreased as well as the density increased.During the high-temperature oxidation process,the internal structure of the secondary columnar grains did not change significantly.In addition,the sintering shrinkage micro-cracks formed during the oxidation process,which was the main cause of inducing the decrease in capacitance and the increase in resistance value of YSZ grain boundary.

关 键 词：等离子喷涂-物理气相沉积 柱状结构 热障涂层 高温氧化 阻抗谱 

分 类 号：TG174[金属学及工艺—金属表面处理]