| 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EBPVD方法制备了陶瓷层厚度分别为180、120和90 μm的3组热障涂层试样，经1 000 ℃高温氧化0、1、10、50和100 h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，EBPVD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。 |
| 关键词: 热障涂层 热疲劳 拉曼光谱 损伤机理 氧化层 |
| DOI：10.11933/j.issn.1007-9289.2015.03.005 |
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| 基金项目: |
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| Structure Evolution and Surface Raman Spectral Characteristics of EB-PVD Thermal Barrier Coatings |
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CHEN Jianwei, ZHAO Yang
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NDT Lab, Laser Institute of Shandong Academy of Science, Jinan 250014
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| Abstract: |
| 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. |
| Key words: thermal barrier coatings thermal fatigue Raman spectroscopy damage mechanism thermally grown oxide (TGO) |
