| 摘要: |
| 可磨耗封严涂层的结构特性对涂层工作性能和服役寿命有重要影响，但缺乏这方面的系统介绍。封严涂层主要用于航空发动机机匣—叶尖之间的间隙控制，提升机匣与叶尖之间的气密性，并作为牺牲涂层来保护叶片叶尖，防止在叶尖与机匣碰摩过程中发生“硬碰硬”的碰撞。综述了多层多孔结构、蜂窝-涂层复合结构和纳米结构三种结构形式的封严涂层及其相应制备技术。发现多层多孔结构目前仍然是封严涂层的主要应用结构，这种结构主要通过在喷涂过程中调控涂层孔隙，达到涂层可磨耗性、结构强度、抗氧化和耐腐蚀等多种性能的平衡。结合蜂窝结构封严与可磨耗封严涂层各自的优点，设计和制备出蜂窝—涂层复合结构封严，这种结构能够提升封严的结构强度和抗氧化性。随着纳米技术的发展，设计和制备出纳米结构封严涂层，相比传统可磨耗封严涂层，纳米结构封严涂层表现出更好的综合性能。最后，提出纳米结构、仿生结构可能成为未来航空发动机可磨耗封严涂层结构设计的发展趋势，而 3D 打印技术的日趋成熟将能够制备出更加多样化的涂层结构。研究结果对可磨耗封严涂层的结构设计、制备和实际应用具有参考意义。 |
| 关键词: 航空发动机 机匣封严 结构设计 制备技术 |
| DOI：10.11933/j.issn.1007?9289.20220623001 |
| 分类号:TG174 |
| 基金项目:国家自然科学基金面上(52172360)和中国民航大学科研基金(3122022PT07)资助项目 |
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| Research Progress on Structural Designs and Preparations of Sealing Coating Between Aero-engine Casing and Blade Tip |
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WANG Tao, CHEN Siyu, MENG Kun, LIU Xingyu
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College of Aeronautical Engineering, Civil Aviation University of China, Tianjin 300300 , China
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| Abstract: |
| The structural characteristics of abradable sealing coatings have a significant influence on their working performance and service life. However, there is a lack of a systematic introduction about structural designs and properties of sealing coatings. Abradable sealing coatings are an important type of coating mainly located on the stator parts of aero-engines. The sealing coating is predominantly used to control clearance and improve airtightness between the aero-engine casing and blade tip. As a result, aircraft engine operating efficiency is improved and fuel consumption reduced. In addition, the abradable sealing coating acts as a sacrificial coating to protect the blade tip and prevent “hard-to-hard” collisions during the rubbing process between the blade tip and casing. Previously, researchers mainly reported that abradable sealing coatings were fabricated by using various preparation technologies and selecting different functional materials, and few reports on the structural design of abradable sealing coatings have been published. This paper reviews sealing coatings with a multilayer porous structure, honeycomb-coating composite structure, and nanostructure, and the preparation technology of different structured abradable coatings are systematically introduced. Sealing coating performance with different structures is described in detail, and the advantages and disadvantages of the above three types of structural sealing coatings are compared. Currently, the multilayer porous structure remains the predominant application structure of the abradable sealing coating because it mainly achieves the balance of various properties such as abradability, structural strength, oxidation resistance, and corrosion resistance of the coating by regulating coating pores during the spraying process. An increase in porosity can improve the coating abrasion. However, other properties, including structural strength, oxidation and corrosion resistance, can be easily weakened. During the working process, the high-porosity sealing coating was prone to wear and peeling, resulting in coating failure. By combining the advantages of the honeycomb structure seal and abradable seal coating, honeycomb-coating composite structure seals were designed and prepared, and properties of this structured sealing coating, such as structural strength and oxidation resistance, were improved. The preparation process for the honeycomb-coated composite structure sealing coating is more complicated than that of the single-structure coating, which reduces sealing structure maintainability of the sealing structure. Nanostructured sealing coatings have been designed and prepared through nanotechnology development. Compared with traditional abradable sealing coatings with a micron structure, nanostructured sealing coatings exhibit improved comprehensive performance. Therefore, nanostructured coatings represent a new direction in the design and preparation of aero-engine abradable seal coatings. However, the challenge for the preparation of nanostructured sealing coatings is that the nanoparticles are easily melted at high temperatures and lose their nanostructures before reaching the substrate surface, leading to failure of coating nanostructures. Finally, this paper proposes that, first, improving the performance of sealing coatings through material system design is a research hotspot. Second, nanostructures and biomimetic structures may become a development trend for aero-engine abradable sealing coating structure design in the future, and the maturity of 3D printing technology will be capable of preparing more diverse coating structures. Therefore, this paper provides a reference for the structural design, preparation, and practical application of abradable sealing coatings. |
| Key words: aero-engine casing seal structural design preparation technology |
