低速重载石墨镶嵌润滑下固体润滑剂的铺展机理分析及评价

Analysis and Evaluation of the Spreading Mechanism of Solid Lubricant under Low-Speed and Heavy-Load Graphite Inlay Lubrication

铜基镶嵌润滑被广泛应用于高性能的滑动轴承中,尽管目前的研究已经能够揭示镶嵌固体润滑的运行机理,但缺乏定量分析.为研究低速重载石墨镶嵌润滑条件下形成的润滑膜成分,探究其中C元素的转移规律,采用UMT-2多功能摩擦磨损试验机开展低速重载工况下销盘模拟试验,试验后对试样表面磨痕不同位置进行能谱分析,研究不同表面粗糙度、速度与载荷对摩擦过程中C元素转移的影响规律,试验结果表明:在试验工况下,随着表面粗糙度从R_(a)=0.8μm增加到R_(a)=2.0μm、摩擦速度从0.06 m/s降低到0.02 m/s以及载荷的100 N增加到175 N,磨痕C元素含量均有所增加.通过数据拟合发现,在速度为0.03 m/s、载荷为150 N以及表面粗糙度R_(a)=1.6μm的工况下,润滑失效距离能达到0.067 m;当仅改变速度为0.02 m/s时,润滑失效距离为0.344 m;而仅改变载荷为100 N时,润滑失效距离为0.119 m,这表明较低的速度和较小的载荷有助于改善润滑性能,提高润滑膜的稳定性,加长润滑失效距离;相反,较高的速度和较大的载荷则会影响润滑膜的稳定性,导致润滑失效距离缩短.这些研究结果揭示了在该工况下C元素的定量转移规律,为在低速重载工况下滑动轴承固体润滑剂位置参数的优化提供了理论依据.

Copper-based graphite inlay lubrication technology has become a key pillar of engineering and technology,providing reliable solutions for many critical applications.Especially in the deep space and deep ocean fields,many important components need to operate in extreme environments,and higher requirements have been put forward for the performance of sliding bearings.Copper-based graphite Inlay lubrication is an integral part of these applications due to its unique properties,including low friction coefficient and excellent wear resistance.For example,sliding bearings perform the critical task of supporting rotating parts and reducing friction losses in aircraft engines.This lubrication method could effectively reduce mechanical wear and extends component life while improving overall performance and reliability.Besides,the lubrication method is also widely used in large gate bottom pivots to ensure the smooth operation of the gate,especially in important occasions that require long-term stability.Although some studies had revealed how copper-based inlay lubrication works,there are still some unresolved issues,such as the quantitative analysis of the formation of solid lubricating films.In order to clearer understand the composition of the lubrication film in the lowspeed and heavy-duty condition for graphite inlay lubrication,especially the migration rule of C element,the UMT-2 multi-function friction and wear testing machine had been adopted to simulate the pin-disk test in the low-speed and heavy-duty conditions.Then the energy spectrum analysis was carried out on different locations of the same path on the specimen surface to study the influence of different surface roughness,friction velocity and load on the migration of C element during friction.The test results showed that the content of C element in the wear marks increases under three conditions:the surface roughness increases from Ra=0.8μm to R_(a)=2.0μm,the friction velocity decreased from 0.06 m/s to 0.02 m/s and the load increased from 100 N to 175 N.Through data fitting,it was found that the lubrication failure distance could reach 0.067 m under the conditions of velocity 0.03 m/s,load 150 N and surface roughness R_(a)=1.6μm.When the speed was only 0.02 m/s,the lubrication failure distance was 0.344 m.When the load was only changed to 100 N,the lubrication failure distance was 0.119 m,which indicated that lower speed and smaller load were helpful to improve the lubrication performance and the stability of the lubrication film,and lengthen the lubrication failure distance.On the contrary,the higher speed and the larger load would affect the stability of the lubrication film,resulting in the shortening of the lubrication failure distance.These results revealed the quantitative migration rule of C element under this working condition,and provided a theoretical basis for optimizing the position parameters of solid lubricants for sliding bearings under low-speed and heavy-load.These research resultes would hopefully drive further improvements in the design of sliding bearings in the future to provide solutions with higher performance and reliability.