聚酰亚胺基多孔含油材料的制备及改性研究

发布时间：2018-03-11 01:00

本文选题：多孔材料　切入点：聚酰亚胺　出处：《哈尔滨工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：航空航天技术的飞速发展,使得对高精度、长寿命含油轴承的需求日益迫切。目前飞行器高速轴在工作结束后,轴承失效时有发生,其根本原因是润滑油供给不足。高速轴轴承是由其多孔含油保持架提供润滑,含油材料本身具备复杂的多孔结构,润滑油可以存储在这些孔道中,轴承正常运转时,润滑油可以持续不断地析出,在摩擦表面形成稳定的润滑油膜。本文充分利用多孔自润滑材料的优点,以空间长寿命机构中的轴承为应用对象,开展了多孔含油自润滑复合材料的改进研究。针对轴承保持架的特殊工作环境,本文选择综合性能优异的聚酰亚胺为基体材料,通过冷压烧结工艺制备多孔含油材料,并采用添加造孔剂的办法,来提高材料的孔隙率。多孔材料的制备工艺,决定了其性能,在制备过程中,本文采用正交实验设计方法设计实验,并对实验结果进行数据分析与处理,最终得到影响多孔含油材料性能的主要工艺参数,进而确定最优方案,最后再用压汞仪测试多孔材料的孔径大小及其分布,验证制备工艺参数的正确性,得出新型贮油材料的制备方法。为了提高多孔材料的机械性能和含油性能,本文以碳纳米管为添加剂,利用纳米材料增强增韧机理和表面能高的特征,改善多孔材料的含油性能、油保持性能、力学性能。研究了碳纳米管的含量、类型对多孔材料综合性能的影响,采用扫描电子显微镜(SEM)观察了复合材料的微观结构,从多角度观察和分析多孔材料表面形态、孔隙特征及磨痕形貌,揭示了碳纳米管填充多孔材料的摩擦磨损机理。针对高速轴轴承在高温、低温、真空、强辐射和高速运动等特殊工况下的性能不稳定问题,本文还提出了一种改善自润滑材料摩擦磨损性能的方法,即油固复合润滑技术,研究了润滑油与固体润滑膜的协同作用机理,建立了油固复合改善磨损的润滑模型,得出了油固复合润滑机理:当润滑油失效或供给不充分不足以形成完整的润滑油膜时,材料表面的固体润滑膜,可以提供补充润滑作用。
[Abstract]:With the rapid development of aerospace technology, the demand for high precision and long life oil-bearing is becoming more and more urgent. The root cause is insufficient supply of lubricating oil. High-speed shaft bearings are lubricated by their porous oil-bearing cages. The oil-bearing materials themselves have complex porous structures in which the lubricating oil can be stored in these channels, and when the bearings are in normal operation, The lubricating oil can continuously precipitate and form a stable lubricating oil film on the friction surface. This paper makes full use of the advantages of porous self-lubricating materials and takes the bearings in the space long life mechanism as the application object. The improvement of porous oil-bearing self-lubricating composite was studied. In view of the special working environment of bearing cage, polyimide with excellent comprehensive properties was selected as matrix material to prepare porous oil-bearing material by cold pressing sintering process. In order to improve the porosity of the materials, the properties of the porous materials are determined by the preparation process of the porous materials. In the process of preparation, the orthogonal design method is used to design the experiments. The experimental results are analyzed and processed, the main process parameters affecting the performance of porous oil-bearing materials are obtained, and the optimal scheme is determined. Finally, the pore size and distribution of porous materials are measured by mercury injection apparatus. In order to improve the mechanical properties and oil-bearing properties of porous materials, carbon nanotubes (CNTs) were used as additives. In order to improve the oil content, oil retention and mechanical properties of porous materials, the effects of content and type of carbon nanotubes on the comprehensive properties of porous materials were studied by using the mechanism of strengthening and toughening and the characteristics of high surface energy. The microstructure of the composite was observed by scanning electron microscope (SEM). The surface morphology, pore characteristics and wear mark morphology of the porous materials were observed and analyzed from various angles. The friction and wear mechanism of porous materials filled with carbon nanotubes is revealed. The performance instability of high speed shaft bearings under special conditions such as high temperature, low temperature, vacuum, strong radiation and high speed motion is pointed out. In this paper, a new method to improve the friction and wear performance of self-lubricating materials, that is, oil-solid composite lubrication technology, is put forward. The synergistic mechanism of lubricating oil and solid lubricating film is studied, and the lubricating model of oil-solid composite wear improvement is established. The mechanism of oil-solid composite lubrication is obtained: when the lubricating oil fails or the supply is insufficient to form a complete lubricant film, the solid lubricating film on the material surface can provide supplementary lubricating effect.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH117.22

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