Thermal Stress Analysis of Environmental Barrier Coatings Considering Interfacial Roughness

Coatings

Yingdong Song¹  Xiguang Gao¹  Jian Shi²  Jiacheng Ren³  Guangwu Fang³ 

[1] Key Laboratory of Aero-engine Thermal Environment and Structure, Ministry of Industry and Information Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;Laboratory of Strength, AECC Sichuan Gas Turbine Establishment, Chengdu 610500, China;School of Mechanical Engineering, Anhui University of Technology, Ma’anshan 243002, China;

关键词: rough interface;    ceramic matrix composite;    environmental barrier coating;    thermal stress;    crack;    finite element method;   

DOI  :  10.3390/coatings10100947

来源: DOAJ

【 摘 要 】

A numerical analysis of the effect of roughness interface on the thermal stress in the environmental barrier coatings for ceramic matrix composites was performed. Based on the concept of representative volume elements, a micromechanical finite element model of the coated composites was established. The rough interfaces between the coating layers were described using sine curves. The cooling process after preparation and the typical service conditions for the CMCs component were simulated, respectively. The results show that the rough interface has little effect on the temperature distribution along the depth direction for the studied T/EBC coatings for SiC/SiC composites. The stress concentration occurs at the rough EBC/BC interface, which is prone to cause delamination cracking. Under typical service conditions, the high temperature can eliminate part of the thermal residual stress. Meanwhile, the thermal gradient will cause large thermal stress in the TBC layer and the stress will result in surface cracks. The stress concentrations appear at the peaks and valleys of rough interfaces. The variation range of thermal stress increases with the roughness amplitude and decreases with the wavelength.

【 授权许可】

Unknown