| CHENG Taotao,WU Zhibing,JIANG Jiayouyu,CAO Yuhan,MA Liang,ZHANG Ying.Inhibition Mechanism of Transverse Crack Propagation in Ceramic Sealing Coating with "Brick-Mud" Structure[J],54(7):212-224 |
| Inhibition Mechanism of Transverse Crack Propagation in Ceramic Sealing Coating with "Brick-Mud" Structure |
| Received:August 13, 2024 Revised:November 25, 2024 |
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| DOI：10.16490/j.cnki.issn.1001-3660.2025.07.018 |
| KeyWord: .$p.#$TAB表 面 技 术#$TAB2025年4月 |
| Author | Institution |
| CHENG Taotao |
College of Science Tianjin , China ;Key Laboratory of Civil Aircraft Airworthiness and Maintenance Tianjin , China |
| WU Zhibing |
College of Aeronautical Engineering, Civil Aviation University of China, Tianjin , China |
| JIANG Jiayouyu |
College of Aeronautical Engineering, Civil Aviation University of China, Tianjin , China |
| CAO Yuhan |
Key Laboratory of Civil Aircraft Airworthiness and Maintenance Tianjin , China |
| MA Liang |
College of Aeronautical Engineering, Civil Aviation University of China, Tianjin , China |
| ZHANG Ying |
College of Aeronautical Engineering, Civil Aviation University of China, Tianjin , China |
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| Abstract: |
| As one of the core technologies of aero-engine, ceramic high-temperature seal coating technology has been widely applied to make aerospace materials. Such coatings face a bottleneck of early spalling failure under thermal cycle conditions. The work aims to take brick-mud structured coating as the research object and explore the effect of pore size on the thermal cycle performance of ceramic brick- mud structured seal coatings based on the pore suction effect, so as to optimize the microstructure of the coating and provide a reference for solving early spalling failure. Finite Element Simulation is used to establish mud layer models with different pore radii (0, 1, 2, 3, 4 µm). The stress field and transverse crack propagation behavior of the mud layer models with different pore sizes under thermal cycle conditions are analyzed. The introduction of pores in the mud' layer has the functions of stress redistribution and stress concentration . The stress concentration position in the mud layer with pores shifts from the brick-mud interface in the pore-free state to the vicinity of the pores. Additionally, the stress field action area significantly decreases. Compared with the original mud layer, the maximum tensile stress (σ22 max) and the maximum shear stress (σ12 max) of the mud layer model with pores significantly increase. Meanwhile, the transverse crack propagation length in the mud layer models with pore radii of 1, 2, 3, and 4 µm decreases by 84.3%, 54.8%, 51.5%, and 59.5%, respectively. At the same time, the energy dissipation level decreases by 98.5%, 62.7%, 91.1%, and 86.9%, respectively. When the pore radius increases from 0 µm to 1 µm, the reduction in transverse crack length is the most significant. Similarly, the reduction in energy dissipation is also the most significant. Because of the stress redistribution and stress concentration , the pores exhibit a crack attraction effect during thermal cycle. As a result, the crack propagation direction is changed and the continuous crack propagation is inhibited. The stress field of the mud layer model with pores is mainly affected by the coupling effect of three factors, namely, brick layer pores, mud layer pore radius, and the thermal expansion and contraction of porous materials. As a result, as the pore radius increases, the crack propagation path in the model with pores exhibits distinct evolution patterns. Among them, small pores with a radius of 1 µm have the weakest stress field for transverse crack propagation driven by thermal cycle, which makes the T1 model have the shortest transverse crack propagation path and the lowest energy dissipation level. |
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