【作者】 朱敏；

【导师】 范勇；

【作者基本信息】 吉林大学 ， 无机化学， 2024， 硕士

【摘要】 摩擦磨损是机械设备运行过程中难以避免的问题,其不仅造成了一定的能量损耗,而且严重影响着设备的使用寿命,从而带来一定的安全隐患。润滑是改善摩擦副的摩擦状态以降低摩擦阻力减缓磨损的常用技术措施。但传统润滑方式常常伴随着润滑剂流失过快、需要不断补充的问题,实际功效有限。自润滑技术是通过消耗自身的固体润滑剂来提供润滑的方式,常用的固体润滑剂包括WS₂、Mo S₂等,因其分子层之间微弱的范德华力,剪切强度较低,易形成润滑膜,被广泛应用于解决摩擦磨损问题。但应用于自润滑技术的固体润滑剂与材料表面的结合性不强,往往不能长时间地作用于摩擦副表面。仿生摩擦学的研究发现,具有一定非光滑特征的微观表面（表面微织构）,如鳞片形、凸包、凹坑、沟槽等具有比光滑表面更小的摩擦阻力。本文针对在干摩擦状态下材料表面的润滑不足问题,将仿生微织构与固体润滑剂结合,设计制备仿生自润滑微织构材料表面,并探究不同织构形状、尺寸及环境参数对材料表面的影响,研究其摩擦磨损性能,分析其自润滑性能机理,为改善机械设备的摩擦磨损、延长其使用寿命提供研究基础。主要研究成果如下:1.受蚯蚓自润滑表面和沙漠蜥蜴鳞片耐磨结构的启发,将自润滑性能与结构耐磨性能结合在一起,在9Cr18Mo金属表面设计并制备了六种仿生自润滑微织构并探究了织构形状对其摩擦磨损性能的影响。首先,提取仿生模型,之后应用激光加工法在9Cr18Mo金属表面加工出正六边形、三角形、圆形、正方形、矩形、菱形等六种不同的连续交错型仿生织构,其中凹槽阵列占基体表面的面积为30%。然后,应用热压烧结法将WS₂纳米球与聚四氟乙烯微粉复合固体润滑剂填充于织构中形成仿生自润滑微织构表面。摩擦磨损实验表明,各微织构表面均具有一定程度的减摩效果。相比于其它织构表面,正六边形织构表面的摩擦系数降低最为显著,降低了85.52%,且减摩效果最为稳定。2.研究不同摩擦工况下,表面的自润滑性能、耐磨减阻性能,对表面仿生参数进行了分析和验证,同时,探究了其自润滑机理。利用激光加工法和热压烧结法,在9Cr18Mo金属表面制备正六边形仿生微织构自润滑表面,探究凹槽宽度和边长改变以及载荷、摩擦速度、摩擦时间等参数变化对表面摩擦学性能的影响。实验结果表明,随着凹槽宽度、边长的增加,样品表面的摩擦系数先减小再增大,且凹槽宽度的影响大于边长变化的影响。此外,在一定程度范围内,自润滑样品在重载、高速下均表现出稳定的减摩效果;同时,经过120 min的摩擦磨损测试,样品的自润滑性能依旧保持良好。这是因为仿生微织构中储存的固体润滑剂在摩擦过程中受摩擦热和剪切作用挤出,在摩擦副接触面形成润滑膜,减小金属表面的摩擦磨损。仿生微织构与固体润滑剂的协同作用所表现出的稳定的自润滑性能,为重载、高速等特殊工况下运行的机械设备零件表面设计提供了重要的研究方向,具有重要的学术价值和实际应用价值。更多还原

【Abstract】 Friction and wear are unavoidable issues in the operation of mechanical equipment,which not only result in energy loss but also seriously affect the service life of the equipment,posing safety hazards.Lubrication is a common technical measure to improve the frictional state of friction pairs,reduce friction resistance,and alleviate wear.However,traditional lubrication methods often come with problems such as rapid loss of lubricants and the need for continuous replenishment,leading to limited practical effectiveness.Self-lubrication technology is a method of providing lubrication by consuming its own solid lubricants.Common solid lubricants used include WS₂,Mo S₂,etc.Due to the weak van der Waals forces between their molecular layers,these lubricants have low shear strength and easily form lubricating films,making them widely used in addressing friction and wear problems.However,the adhesion between solid lubricants applied in self-lubrication technology and material surfaces is often weak,and they cannot effectively act on the friction pair surfaces for a long time.Research in biomimetic tribology has found that micro-surface features with certain non-smooth characteristics（surface micro-textures）,such as scales,protrusions,indentations,grooves,etc.,have lower friction resistance than smooth surfaces.This article focuses on the issue of insufficient lubrication on material surfaces under dry friction conditions.It combines biomimetic textures with solid lubricants to design and prepare biomimetic self-lubricating micro-textured material surfaces.It explores the effects of different texture shapes,sizes,and environmental parameters on the biomimetic self-lubricating micro-textured surfaces,studies their friction and wear performance,and analyzes the mechanism of self-lubrication.The research provides basis to improve the friction and wear of mechanical equipment and extend their service life.The main research findings are as follows:1.Inspired by the self-lubricating surface of earthworms and the wear-resistant structure of desert lizard scales,the self-lubricating performance is combined with the structural wear resistance.Six types of biomimetic self-lubricating micro-textured surfaces were designed and prepared on the surface of 9Cr18Mo metal,and the influence of texture shape on their friction and wear performance was explored.Firstly,the bionic model was extracted,and then six kinds of continuous staggered bionic textures,including hexagon,triangle,circle,square,rectangle and diamond,were machined on the 9Cr18Mo metal surface by laser processing method,in which the groove array accounted for 30%of the surface area of the matrix.Then,the WS₂nanospheres and polytetrafluoroethylene micro-powder composite solid lubricant were filled into the texture using a hot pressing sintering method to form a biomimetic self-lubricating micro-textured surface.Friction and wear experiments showed that each micro-textured surface had a certain degree of friction reduction.Compared with other textured surfaces,the friction coefficient of the hexagonal textured surface decreased most significantly,by 85.52%,and exhibited the most stable friction reduction effect.2.The self-lubricating properties and wear resistance reduction properties of the surface under different friction conditions were studied,the bionic parameters of the surface were analyzed and verified,and the self-lubricating mechanism was explored.Using laser processing and hot pressing sintering,a hexagonal biomimetic textured self-lubricating surface was prepared on the surface of 9Cr18Mo metal.The effects of changes in groove width and side length,as well as parameters such as load,sliding speed,and sliding time,on the surface tribological properties were investigated.The experimental results showed that with the increase in groove width and side length,the friction coefficient of the sample surface first decreased and then increased,with the influence of groove width being greater than that of side length changes.In addition,within a certain range,the self-lubricating samples exhibited stable friction reduction effects under heavy loads and high speeds;furthermore,after 120 minutes of friction and wear testing,the self-lubricating performance of the samples remained good.This is because the solid lubricant stored in the biomimetic texture is extruded by frictional heat and shear action during the friction process,forming a lubricating film on the friction pair contact surface,reducing the friction and wear of the metal surface.The stable self-lubricating performance shown by the synergistic effect of bionic micro-texture and solid lubricant provides an important research direction for the surface design of mechanical equipment parts operating under special conditions such as heavy load and high speed,and has important academic and practical value.更多还原