摘要
为了提高航空发动机热端部件的热障涂层(TBCs)与基体的结合强度、延长涂层使用寿命,利用激光快速成型技术在高温合金基体上制备了网状结构的衬垫,用等离子喷涂法制备了陶瓷涂层,并通过实验比较该陶瓷涂层与传统两层结构涂层的抗热震性能。基于热弹塑性力学理论,建立了二维有限元数值模型,分析了热震中网状衬垫对热障涂层应力分布的影响。结果表明,传统两层结构与具有网状衬垫的热障涂层分别在经历45和111次热震后失效,且由于陶瓷层和粘结层之间生长的热氧化层(TGO),边缘位置的陶瓷层均发生剥落。数值分析结果表明,网状衬垫的加入使得涂层边界区域的应力集中得到改善,涂层剥落被有效抑制,从而使得热障涂层抗热震性能提高。
In order to improve the bonding strength between substrates and thermal barrier coatings （TBCs） of hot components of aircraft engines and prolong service life of coatings, the laser rapid prototyping technology is applied to fabricate a network structure on a superalloy substrate, and the plasma spraying method is for ceramic coatings. The thermal shock resistance of these TBCs is studied experimentally and compared with that of traditional coatings with a two-layer structure. To further analyze the effect of the network structure on the stress distribution of TBCs, a two-dimensional finite element numerical model is established based on the thermo-elastic-plastic theory. The results show that the TBCs with a traditional two-layer structure and a network structure fail after 45 and 111 thermal shocks, respectively. Due to the thermally grown oxide layer （TGO） along the interface between the layers of ceramic and bond coating, a spalling of the ceramic layer near the edge is observed for both kinds of TBCs. Further numerical analysis results show that the concentration of stress on the boundary region is relatively released with the help of the network structure. Accordingly, the cracks originated on the boundary are effectively suppressed, which reasonably makes the thermal shock resistance improvement of TBCs.
作者
周逸波
秦渊
杨森
Zhou Yibo;Qin Yuan;Yang Sen(School of Materials Science and Engineering, Nanjing University of Science and Technology Nanjing, Jiangsu, 210094, China)
出处
《激光与光电子学进展》
CSCD
北大核心
2018年第2期335-343,共9页
Laser & Optoelectronics Progress
基金
中央高校基本科研业务费专项资金(30920130112010)
关键词
激光技术
热障涂层
网状结构
激光快速成型
抗热震性
失效机理
laser technique
thermal barrier coatings
network structure
laser rapid prototyping
thermal shock resistance
failure mechanism
