EB-PVD热障涂层的结构演变与表面拉曼光谱特性  

Structure Evolution and Surface Raman Spectral Characteristics of EB-PVD Thermal Barrier Coatings

作　　者：陈建伟[1] 赵扬[1] 

机构地区：[1]山东省科学院激光研究所无损检测平台,济南250014

出　　处：《中国表面工程》2015年第3期30-35,共6页China Surface Engineering

基　　金：国家自然科学基金(51205240);山东省杰出青年科学家计划(BS2011ZZ016);济南市高校科研院所创新项目(201401220)

摘　　要：热障涂层被广泛应用于航空发动机和燃气轮机等高温部件,其破坏机理和无损检测手段是研究中急需解决的问题。采用EB-PVD方法制备了陶瓷层厚度分别为180、120和90μm的3组热障涂层试样,经1 000℃高温氧化0、1、10、50和100h后,用HR800激光显微拉曼光谱仪测得试样表面的拉曼光谱特性,利用扫描电镜(SEM)观测了试样内部裂纹及氧化层(TGO)厚度的演变。研究表明,EB-PVD热障涂层裂纹主要发生在陶瓷层内部及陶瓷层与粘结层的界面处,粘结层和基体界面处产生裂纹的概率相对较小;同等条件下,增大陶瓷层的喷涂厚度,可以减缓氧化层的生长速度,但是会增大陶瓷层表面应力;热障涂层表面残余应力会随着热氧化时间的增加而增大,当表面残余应力减小时表明陶瓷层中有明显的裂纹或脱落产生。Thermal barrier coatings have been widely used in high temperature components such as aero engines and gas turbines. The failure mechanism and nondestructive failure testing are urgent to be solved in the research on thermal barrier coatings. Three groups of thermal barrier coating specimens were prepared using electron beam physical vapor deposition （EBPVD） method. The thickness of the ceramic layer of the specimens are 180, 120 and 90 μm. The specimens were oxidized at 1 000 ℃ for 0, 1, 10, 50 h and 100 h. The Raman spectroscopy of each sample surface was measured by HR800 laser Raman microscope. The crack and thermally grown oxide （TGO） thickness were observed using scanning electron microscopy （SEM）. Results show that the cracks mainly initiate inside the ceramic layer and at the interface between the top coating （TC） and the bonding coating （BC）. The probability of crack initiation at the interface between the BC and the substrate is relatively small. The growth of the oxidation layer decrease with the increase of ceramic thickness. The surface residual stresses will increase with the increase of ceramic layer thickness. The surface residual stress of the thermal barrier coating will also increase with the increase of the oxidation time. The reduction of the surface residual stress means the generation of the cracks or peelings.

关 键 词：热障涂层 热疲劳 拉曼光谱 损伤机理 氧化层 

分 类 号：TG174.444[金属学及工艺—金属表面处理] V254.2[金属学及工艺—金属学]