Experimental and numerical investigation on the thermal and mechanical behaviours of thermal barrier coatings exposed to CMAS corrosion
Experimental and numerical investigation on the thermal and mechanical behaviours of thermal barrier coatings exposed to CMAS corrosion
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DOI：
10.1007/s40145-021-0457-2
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发表时间：
2020-11
影响因子：
16.9
通讯作者：
Dongxu Li;P. Jiang;R. Gao;Fan Sun;X. Jin;Xueling Fan
中科院分区：
文献类型：
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作者：
Dongxu Li;P. Jiang;R. Gao;Fan Sun;X. Jin;Xueling Fan
钙镁铝硅酸盐（CMAS）腐蚀是导致热障涂层失效的关键因素。CMAS作用显著改变了TBC的温度场和应力场，导致TBC的分层或剥落。研究了悬浮等离子喷涂（SPS）制备的TBC在CMAS攻击下的演变过程。CMAS腐蚀导致反应层的形成和TBC的弯曲。在此基础上，提出了一种腐蚀模型来描述TBC反应层的产生、演变和弯曲。然后，对独立TBC和完整TBC体系在CMAS攻击下的腐蚀过程进行了数值模拟研究。腐蚀模型是连接两个数值模型的桥梁。结果表明：CMAS腐蚀对峰值应力等应力场有显著影响，而对稳态温度场影响较小；应力峰值随保温时间的延长而增大，增加了TBC破裂的风险。Mises应力沿反应层厚方向呈非线性增加。此外，在传统的破坏区域，如面层和粘结层的界面，在CMAS腐蚀过程中应力发生了明显的变化。
Calcium-magnesium-alumino-silicate (CMAS) corrosion is a critical factor which causes the failure of thermal barrier coating (TBC). CMAS attack significantly alters the temperature and stress fields in TBC, resulting in their delamination or spallation. In this work, the evolution process of TBC prepared by suspension plasma spraying (SPS) under CMAS attack is investigated. The CMAS corrosion leads to the formation of the reaction layer and subsequent bending of TBC. Based on the observations, a corrosion model is proposed to describe the generation and evolution of the reaction layer and bending of TBC. Then, numerical simulations are performed to investigate the corrosion process of free-standing TBC and the complete TBC system under CMAS attack. The corrosion model constructs a bridge for connecting two numerical models. The results show that the CMAS corrosion has a significant influence on the stress field, such as the peak stress, whereas it has little influence on the steady-state temperature field. The peak of stress increases with holding time, which increases the risk of the rupture of TBC. The Mises stress increases nonlinearly along the thick direction of the reaction layer. Furthermore, in the traditional failure zone, such as the interface of the top coat and bond coat, the stress obviously changes during CMAS corrosion.