不同含量盐水介质中丁腈橡胶水润滑轴承材料摩擦学特性分析

以水润滑轴承用丁腈橡胶(NBR)材料为研究对象,在CBZ-1摩擦磨损试验机上开展其在清水及不同盐分含量水介质中以及不同速度及载荷下的摩擦学试验,对比分析其摩擦因数、磨损量以及磨损表面形貌等摩擦学特性的变化规律。结果表明:盐水质量分数、速度和载荷对丁腈橡胶的摩擦学性能影响显著,其摩擦学特性的变化是盐水质量分数、载荷、速度以及丁腈橡胶的黏弹性等因素共同作用的结果;丁腈橡胶材料与锡青铜配副的摩擦因数随转速的升高而降低,随载荷的增加而降低;随着盐水质量分数的增加,摩擦副的摩擦因数和磨损量先增大而后均有所减小,这是因为盐水质量分数通过影响润滑介质的黏度来改变水润滑的效果,通过对铜盘的腐蚀作用来改变摩擦副的摩擦情况,从而在整体上影响摩擦因数和磨损量的变化。     

PTFE基三层滑动轴承材料与不同材料配副时的摩擦学特性

PTFE基三层滑动轴承复合材料与不同材料组成的摩擦副有着不同的摩擦学特性,研究这些摩擦副的摩擦学特性,对于优化摩擦副配副材料具有重要的实用价值。研究PTFE基三层复合材料与钢铁材料、有色金属以及聚合物材料进行配副时的摩擦磨损性能,通过扫描电镜观察磨损表面的微观形貌,分析不同摩擦副的摩擦磨损机制,并给出摩擦副配副的优选结果。结果表明:PTFE基三层滑动轴承材料与钢铁材料以及聚合物材料配副时,其磨损机制为剥层磨损,摩擦学性能较好;而与有色金属配副时,其磨损机制为黏着磨损,摩擦学性能较差。     

表面粗糙度对黄铜/铬青铜摩擦副载流摩擦磨损性能影响的研究

以黄铜/铬青铜为摩擦副,在销-盘式摩擦磨损试验机上进行了载流摩擦学特性研究,探讨了载流条件下摩擦副的表面粗糙度对摩擦学特性的影响.结果表明:摩擦副表面粗糙度存在一个最佳值,使质量磨损率最小,载流效率、载流稳定性也较好;摩擦因数先随表面粗糙度的降低而升高,当表面粗糙度降低到一定程度以后摩擦因数的变化趋于平稳.质量磨损率随着表面粗糙度的降低先减小后增大;载流导致质量磨损率增大,且随着电流密度的增大,这种影响更加显著.     

空间用导电滑环真空高低温摩擦力矩特性分析

为研究空间用导电滑环在热真空试验过程中的摩擦力矩特性,根据滑动电摩擦理论和摩擦学理论,从同真空和温度两方面对导电滑环的环-刷摩擦副和轴承摩擦副的摩擦力矩特性进行分析。分析结果表明:真空环境主要影响环-刷摩擦副的摩擦界面特性,造成摩擦副摩擦因数增大,从而导致摩擦力矩增大;高低温环境主要影响轴承的预紧力,在高温环境下影响较小,在低温环境下导致预紧力增大,摩擦力矩显著增大。通过搭建摩擦力矩测试系统,对理论分析结果进行了验证。试验结果表明:真空和高低温环境下滑环摩擦力矩分别约为常温常压下摩擦力矩的1.2和1.4倍;滑环摩擦力矩受轴承摩擦力矩影响较大,环-刷摩擦副对摩擦力矩影响较小。     

重载丝杠螺母副的摩擦学系统模型的建立

在基本摩擦学理论和实验的基础上 ,分析了某种选定的摩擦副在某种选定的摩擦学工况条件下的摩擦学系统特性 ,建立了轧机压下装置中重载丝螺母副的摩擦学特性与载荷之间关系的数学模型 ,推导出相对准确的摩擦系数—载荷 ,磨损率—载荷计算公式 ,与实验结果比较有较好的吻合性。该数学模型可为摩擦学系统特性转化的研究提供研究参照体 ,亦可为工程设计人员在摩擦学设计时提供有效的计算工具。     

PTFE基复合材料海水润滑下的摩擦学性能研究

研究碳纤维/聚四氟乙烯（CF/PTFE）、玻璃纤维/聚四氟乙烯（GF/PTFE）复合材料与氮化硅陶瓷配副在海水环境下的摩擦学性能与润滑机制,分析滑动速度对摩擦副海水润滑性能的影响规律。结果表明：在海水润滑条件下,随着滑动速度的增加,PTFE、CF/PTFE、GF/PTFE材料与Si3N4陶瓷配副时的摩擦学性能均有明显改善,摩擦因数与磨损率均呈显著降低的趋势,其中CF/PTFE复合材料表现出更为优异的摩擦学性能,在1 000 r/min滑动速度下摩擦因数低至0.026。磨损表面表征结果表明,在海水润滑条件下,PTFE基复合材料在摩擦过程中由于摩擦化学反应生成了润滑膜,可为摩擦副提供良好的润滑和减磨作用,从而减少摩擦磨损行为的发生。     

面接触条件下织构表面摩擦特性研究

为研究织构表面对面接触摩擦副摩擦特性的影响,设计和制造4个表面高度算术平均值相同、表面微凹坑面积占有率分别为7%、14%、21%、28% 的试件,选用HDM20端面摩擦磨损试验机,针对油润滑和脂润滑两种润滑剂,在不同载荷、转速等工况和不同摩擦副配对材料等条件下进行了试验研究,探讨表面形貌对摩擦特性的影响规律,并使用Talysurf CCI Lite 非接触式三维光学轮廓仪对试样进行三维表面测量,采用ISO25178定义的体积参数和连通性系数对三维表面形貌进行表征,从而得出表面体积参数及连通性系数与摩擦因数的关系。结果表明：在油润滑条件下表面形貌的微观结构特性对摩擦的影响要比脂润滑条件下的更显著;在钢对铜摩擦副条件下织构表面的摩擦因数变化比较复杂,在钢对钢摩擦副条件下织构表面的摩擦因数变化相对平稳;在不同的条件下,最优的表面微观结构特性也不同;将连通性系数和体积参数结合起来对表面形貌进行表征将更有利于表面微观结构特性的摩擦学设计。     

铜基粉末冶金材料/铬青铜摩擦副中的电弧侵蚀机制

以铜基粉末冶金材料/铬青铜为摩擦副,在销-盘式摩擦磨损试验机上进行载流摩擦学特性研究。在多种条件下试验,探讨载流条件下铜基粉末冶金/铬青铜摩擦副中的电弧侵蚀机制。结果表明:载流摩擦下销试样磨损形式主要以机械磨损、电流和机械综合作用下的磨损、电弧侵蚀为主;电弧对铜基粉末冶金材料的侵蚀主要是熔融材料的黏着磨损、磨粒磨损,电弧作用下材料表层的疏松化、材料的蒸发与转移、材料的熔融积瘤。     

活塞环——缸套摩擦磨损研究

本文通过摩擦磨损试验仪试验数据,比对出活塞环与缸套在贫油和富油状态的摩擦学特性,揭示出润滑状态是影响活塞环与缸套摩擦副摩擦学特性的关键因素,为产品设计和故障分析提供数据支持。     

受流条件下碳碳复合材料的摩擦学特性研究

以碳碳复合材料和铬青铜作为配副,研究了受流条件下碳碳复合材料的摩擦学特性.结果表明:速度、载荷和电流是影响受流条件下碳碳复合材料摩擦学特性的重要因素.在电流一定的条件下,碳碳复合材料的摩擦因数和磨损率随速度的增大而增大;摩擦因数随载荷的增加而增大,而磨损率随载荷的增加而减小.在载荷一定条件下,随着电流的增加,碳碳复合材料的摩擦因数减小而磨损率增大.与一般条件下的摩擦学特性相比较,碳碳复合材料在受流条件下的摩擦因数明显降低,而磨损率却明显提高.     

Tribological Properties of Lubricating Films on the Al-Si Alloy Surface via Laser Surface Texturing

Dimpled textures were prepared by using a pulse solid laser on the surface of Al-Si alloy. The combination of laser surface texturing (LST) and MoS₂ solid lubricant as well as their tribological properties were investigated in this article. The obtained friction and wear data were critically analyzed to investigate how the parameters of texture influence the tribological performance of Al-Si alloy. Furthermore, morphological investigations of the transfer layers on the worn surfaces were performed and the wear mechanisms are discussed. The results show that the combination of LST and solid lubricant improves the tribological characteristics of Al-Si alloy. The friction coefficient of Al-Si alloy: steel friction pairs can be reduced to 0.15 under dry friction. The lubrication mechanism is attributed to a synergetic effect of providing solid lubricant and traps wear debris in the dimples. It was found that the optimum density of structure was 37% for excellent tribological properties.     

纳米铜润滑添加剂在四球机上的摩擦学性能研究及机理探讨

用MRS-10J四球摩擦磨损试验机考察了N68基础油和添加了自修复纳米铜润滑添加剂NT1的N68NT1的摩擦学性能,用扫描电子显微镜（SEM）、x射线能量色谱仪（EDS）分析了钢球表面的磨斑形貌和组成,同时初步分析了纳米铜润滑添加剂的润滑机理.结果表明：自修复纳米铜润滑油添加剂NT1能显著改善N68基础油的摩擦学性能;在载荷为296 N、392 N、490 N,试验时间为30 min的试验条件下,摩擦副的摩擦因数同基础油的相比分别下降了33.8%、39.4%和55.5%;钢球的磨斑直径分别下降了46.5%、45.6%和32.5%;同N68相比,N68NT1的pB值提高了33.3%;这可能同摩擦过程中钢球表面上沉积膜的协同作用有关.     

Determination of the tribological size effects in microforming through the scaled upsetting tests of disks

Microforming is a very attractive and suitable manufacturing technology for the production of microscale parts since it enables to utilize a wide range of materials with high production rates and minimized material loss. Previous researches on microforming have shown that the traditional friction model can lead to significantly erroneous results. Thus, for successful development and applications of microforming process, a critical consideration of the tribological size effect is required. This paper investigates the tribological size effect in microforming of pure copper by scaled upsetting experiments of disks. In order to explain the mechanism of the friction size effect, a simple theoretical analysis was performed based on the upper-bound theorem and the lubricant pocket model. The sensitivity of the friction to the deformation characteristics of the material was analyzed using finite element analysis (FEA) under a wide range of friction conditions. In addition, upsetting tests of disks enabled to verify the effectiveness of the theoretical and FEA models and explained the change of the frictional behavior with the reduction of the part size qualitatively and quantitatively.     

人工关节材料的表面润滑设计与应用

人工关节的摩擦磨损问题仍然是基础研究中最重要的问题,借助表面改性技术改善假体的摩擦学性能是人工关节未来发展的必经之路。从润滑角度考虑,对假体关节材料摩擦性能的研究主要集中在表面功能化润滑结构设计以及新型仿生润滑剂研究两方面。针对功能化润滑结构,介绍表面织构设计以及聚合物刷的应用,分析表面织构参数对不同运动工况下摩擦副摩擦性能的影响,阐述表面织构的润滑机制;总结不同种类的聚合物刷结构对摩擦体系耐磨性能的调控,阐明"刷型"结构在摩擦界面的水润滑特点,提出环境介质对聚合物刷结构及性质的影响作用。针对关节润滑剂,介绍传统的关节滑液组分向聚合物仿生润滑剂的拓展。指出微/纳结构的嵌套设计与协同润滑以及润滑剂结构仿生与功能仿生的结合,将是未来的重要发展方向。     

The Size Effect of Boron Nitride Particles on the Tribological Performance of Biolubricants for Energy Conservation and Sustainability

The size of particulate additives in a bio-based lubricant influences their friction and wear performance during sliding contact. The present investigation evaluates the effect of boron nitride particle size on the tribological performance of canola oil-based lubricant mixtures. During sliding experiments, micron-, submicron-, and nanometer-sized boron nitride particle additives were considered. Friction and wear measurements were carried out on the prepared lubricant mixtures using a pin-on-disk tribometer at ambient conditions. A scanning electron microscope and optical profilometer were used for topographical studies to evaluate the influence of particle size on wear damage and surface roughness. The results revealed that the nanometer-sized particulate mixture outperformed micron- and submicron-sized particulate combinations in terms of friction and wear performance and provided a 90 % smoother surface finish. Furthermore, the tribological response of canola oil containing micron- or submicron-sized particles was found to be significantly enhanced by the addition of nano-sized particles, where the friction and wear were reduced by 40 and 70 %, respectively. It was inferred that the nano-sized particles were able to better coalesce in the asperity valleys due to their small size and spherical shape, which provided them with enhanced tribological properties in comparison with the micron- and submicron-sized particles that were larger and exhibited a plate-shaped in geometry. Newly developed non-dimensional surface roughness parameters were introduced to quantify the influence of particle size and the mechanisms involved in the tribological phenomena. The state of lubricants derived from bio-based feedstock were subsequently explored for their influence on energy conservation and sustainability, as well as their potential impact on the lubricant market place.     

基于油液分析的汽车发动机摩擦系统故障诊断专家系统知识库的建立

采集汽车发动机润滑系统中摩擦副经历磨擦学行为的信息是诊断发动机摩擦系统故障的有效手段。油液分析从摩擦学系统的润滑剂和磨损物两方面获得磨擦副的润滑和磨损状态的信息。但常规的油液分析信息处理方法上的不足影响了油液分析技术在汽车行业的实际应用,开发基于油液分析的故障诊断系统,无疑会改善油液分析的诊断准确性和诊断成本。本文着重针对该诊断专家系统知识库的建立,     

微织构光固化填充h-BN的巴氏合金表面摩擦学性能

为了提高巴氏合金在油润滑条件下的摩擦学性能,在巴氏合金表面加工凹坑微织构并利用光固化填充方法填充六方氮化硼(h-BN)固体润滑剂,制备出h-BN与表面微织构相结合的复合润滑结构。研究复合润滑结构在油润滑条件下的摩擦学性能及其减摩润滑机制。结果表明：复合润滑结构的摩擦学性能远高于未织构面和纯织构面;当凹坑微织构直径较小时,织构密度为10%～20%时,复合润滑结构摩擦因数较小,而凹坑直径较大时,随着织构密度的增加,复合润滑结构摩擦因数逐渐减小;当织构密度小于20%时,凹坑直径较小的复合润滑结构摩擦因数小,当织构密度达到30%时,随着凹坑直径的增加,复合润滑结构摩擦因数减小。复合润滑结构能够改善巴氏合金表面摩擦学性能,是因为h-BN固体润滑剂的释放在巴氏合金表面形成了固体润滑薄膜,避免了润滑油膜较薄处的巴氏合金表面直接与45钢表面接触,且释放h-BN固体润滑剂后的微织构凹坑可以起到收集磨粒,储存润滑油的作用。     

纳米铜添加工艺对润滑油摩擦学性能的影响

探讨了纳米铜不同分散工艺和添加量对润滑油摩擦学性能的影响。分别采用超声分散和球磨分散工艺，将3种不同工艺制备的纳米铜材料溶于SF15W／40机油中，在T-11摩擦磨损试验机上进行摩擦学性能试验。结果表明，其中一种纳米铜能够提高基础油的减摩性能，采用超声分散比采用球磨分散的减摩性能好。随着纳米铜浓度的增加抗磨性能有明显的提高，分析认为纳米铜在摩擦表面的沉积有利于提高摩擦学性能。     

Analysis of friction contact between wavy surfaces

The objective of the present work is to study the tribological behaviour of two contact bodies coated with solid lubricant films. The suggested model relaxes two restrictions of the classical Hertz theory by introducing the friction effect and the elastic-plastic behaviour as irreversible effects.The analysis is based on the automated direct procedure developed by Mahmoud and Salamon and an extension of that model to deal with plastic flow and Coulomb friction between contact surfaces. The proposed model is applied to a typical example of a wavy surface pressed against a flat strata. Both the wavy surface and the flat strata are coated with a hard lubricant film. The history of the advancing contact and the initiation of the plastic flow are determined through the procedure of the model.