等离子喷涂Gd2Zr2O7-SrZrO3复合陶瓷涂层的微观结构和性能  

Microstructure and Properties of Plasma Sprayed Gd2Zr2O7-SrZrO3 Composite Ceramic Coatings

作　　者：李英杰 马文[1] 黄威 杨曦 刘颖[1] 陈伟东[1] 白玉[1] Li Yingjie;Ma Wen;Huang Wei;Yang Xi;Liu Ying;Chen Weidong;Bai Yu(Inner Mongolia Key Laboratory of Thin Film and Coatings Technology,Inner Mongolia University of Technology,Hohhot 010051,China)

机构地区：[1]内蒙古工业大学内蒙古自治区薄膜与涂层重点实验室,内蒙古呼和浩特010051

出　　处：《稀有金属材料与工程》2020年第2期555-560,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51462026,51672236);内蒙古科技重大专项(2018-810)。

摘　　要：通过固相反应法合成了Gd2Zr2O7-SrZrO3 (GZSZ,Gd2Zr2O7:SrZrO3=7:3)复合陶瓷粉末,并采用喷雾造粒法和大气等离子喷涂法分别制备了适合等离子喷涂使用的相应喷涂粉末及涂层。使用X射线衍射、扫描电子显微镜对粉末和涂层的相组成、显微结构进行分析。借助激光热导仪、高温热膨胀仪对涂层的热扩散系数和热膨胀系数、烧结系数进行了表征。结果表明,制备的GZSZ复合陶瓷粉末和涂层都由Gd2Zr2O7和SrZrO3两相组成,粉末中的Gd2Zr2O7为烧绿石结构,而涂层中的Gd2Zr2O7为萤石结构,SrZrO3都为钙钛矿结构。制备态GZSZ涂层的孔隙率为~14%。GZSZ涂层1400℃热处理5 h后的热膨胀系数为(9.8~11.2)×10-6 K-1。制备态GZSZ涂层的热导率为~0.8 W·m-1·K-1,与制备态SrZrO3涂层的热导率~1.0 W·m-1·K-1相比降低~20%。1400℃热处理360 h后GZSZ涂层的热导率增加到~1.5 W·m-1.K-1。综上表明,GZSZ涂层是一种很有前景的复合陶瓷热障涂层材料。Gd2Zr2O7-SrZrO3(GZSZ,Gd2Zr2O7:SrZrO3=7:3) composite ceramic powder was synthesized by solid state reaction.Spray drying and atmospheric plasma spray(APS) method were used to prepare corresponding spray powders and coatings,respectively.The phase composition and micro structures of the spray dried powders and APS coatings were characterized by X-ray diffraction and scanning electron microscopy.The thermal diffusivity,thermal expansion coefficient and sintering coefficient of the coatings were characterized by a laser flash method and a high-temperature dilatometer.The result shows that both GZSZ composite powders and coatings are composed of Gd2Zr2O7 and SrZrO3.The Gd2Zr2O7 powder has a pyrochlore structure,while the Gd2Zr2O7 coating has a fluorite structure,and both the SrZrO3 powders and coatings have a perovskite structure.The porosity of the coating is^14%,and its thermal expansion coefficient after heat treatment at 1400℃ for 5 h is(9.8~1 1.2)×10-6 K-1.The thermal conductivity of the as-sprayed GZSZ coating is^0.8 W·m-1·K-1.which is^20% lower than that of the SrZrO3 coating(~1.0 W·m-1·K-1).And the thermal conductivity of the GZSZ coating increases to^1.5 W·m-1·K-1 after heat treatment at 1400℃ for 360 h.The results indicate that the GZSZ coating is a promising thermal barrier coating material.

关 键 词：大气等离子喷涂 热障涂层 热导率 热膨胀系数 

分 类 号：TQ174.758.16[化学工程—陶瓷工业]