不同电子束流EB-PVD制备YSZ热障涂层的组织结构演变、热循环寿命与失效行为分析  

Microstructure evolution,thermal cycling lifetime,and failure behavior analysis of YSZ thermal barrier coatings prepared by EB-PVD with different electron beam currents

作　　者：牟仁德 丁宁 刘冠熙 罗宇晴 戴建伟 MU Rende;DING Ning;LIU Guanxi;LUO Yuqing;DAI Jianwei(Surface Engineering Division,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;The Sixth Military Representative Office of the Airborne Equipment Department in Beijing,Beijing 100013,China)

机构地区：[1]中国航发北京航空材料研究院表面工程研究所,北京100095 [2]空装驻北京地区第六军事代表室,北京100013

出　　处：《材料工程》2024年第12期44-52,共9页Journal of Materials Engineering

基　　金：国家科技重大专项项目(J2019-Ⅶ-0010-0150);超高温耐蚀热障涂层技术项目(30204);国家自然科学基金项目(52202073)。

摘　　要：采用电子束物理气相沉积技术在不同电子束流下(1.2,1.8,2.4 A)制备YSZ热障涂层,分析表征不同电子束流下YSZ涂层的相结构和显微组织形貌变化,并对热障涂层进行了1150℃热循环寿命测试,同时通过微观组织结构演变对涂层失效行为进行分析。结果表明:不同电子束流下YSZ涂层均具有非平衡四方相结构,随着电子束流的增加,涂层柱状晶尖端结构逐渐由三角状向金字塔状再向山脊状演变,柱状晶由纤细结构转变为粗大结构,枝晶减少,排列有序性增加,由于YSZ涂层柱状晶纳米孔结构的存在使得热导率略微降低。1.8 A制备的YSZ涂层具有895周次的最优异热循环寿命,约为1.2 A下制备YSZ涂层的2倍,2.4 A下制备YSZ涂层的1.3倍,获得了低电子束流制备的纤细柱状晶结构优先烧结失效、高电子束流制备的粗大柱状晶优先热生长氧化(TGO)层应力累积失效的不同组织结构失效行为,1.8 A制备的柱状晶结构可平衡两种失效行为,有效延长YSZ热障涂层热循环寿命。The electron beam-physical vapor deposition(EB-PVD)technology was employed to fabricate yttria-stabilized zirconia(YSZ)thermal barrier coatings at different electron beam currents(1.2,1.8,2.4 A).The phase structure and microstructural morphology of YSZ coatings at different electron beam currents were analyzed and characterized.The thermal barrier coatings were also subjected to a 1150℃thermal cycling life test.The failure behaviors of coatings were analyzed by the evolution of the microstructure.The results show that YSZ coatings at different electron beam currents all possess a non-equilibrium tetragonal phase structure.As the electron beam current increases,the columnar grain tip structure of the coating evolves from a triangular shape to a pyramidal shape and then to a ridge-like shape,with the column structure changing from a slender structure to a coarse structure,the dendrites decreasing,and the arrangement becoming more orderly.The thermal conductivity is lower slightly due to the appearance of ordered nanopores in the column of YSZ coatings.The YSZ coating prepared at 1.8 A demonstrates the most excellent thermal shock life of 895 cycles,approximately twice that of the YSZ coating prepared at 1.2 A and 1.3 times that of the YSZ coating prepared at 2.4 A.The slender columnar grain structure prepared at a low electron beam current is prone to sintering failure,while the coarse columnar grain structure prepared at a high electron beam current is prone to thermally grown oxide(TGO)layer stress accumulation failure.The columnar grain structure prepared at 1.8 A could balance the two types of failure behaviors,effectively extending the thermal cycling life of the YSZ thermal barrier coating.

关 键 词：热障涂层 电子束物理气相沉积 显微结构 热循环 失效行为 

分 类 号：TG174.453[金属学及工艺—金属表面处理] TB33[金属学及工艺—金属学]