铁基材料表面粘结润滑涂层摩擦学性能研究

为改善铁基粉末冶金材料的摩擦磨损性能,在其表面制备了复合粘结润滑涂层,分别在干摩擦和油润滑条件下进行摩擦磨损试验与分析,结果表明:石墨、二硫化钼两者有协同作用,复合粘结润滑涂层具有良好的润滑减摩性能,油润滑条件下,涂层以石墨含量较多者为佳,干摩擦条件下,涂层以MoS2含量较多者为佳,采用硅烷偶联剂处理后,进一步提高了复合涂层的减摩耐磨性能和承载能力.     

改性UHMWPE水润滑轴承材料摩擦磨损性能研究

以超高分子量聚乙烯为基体,用纳米二硫化钼和氟橡胶对其进行改性,制备一种新型复合UHMWPE水润滑轴承材料。在轴系试验台SSB-100上,研究复合UHMWPE材料在不同转速下的摩擦磨损性能,并分析其磨损形貌。结果表明,采用纳米二硫化钼改性UHMWPE时并不能有效改善其摩擦性能;采用氟橡胶改性时UHMWPE复合材料的摩擦因数呈现整体下降、局部波动的趋势,并在氟橡胶质量分数为20%时摩擦因数最低;二硫化钼和氟橡胶协同改性UHMWPE材料的摩擦因数随着二硫化钼和氟橡胶含量的升高而逐渐下降,其中纳米二硫化钼质量分数为8%、氟橡胶质量分数为16%的材料摩擦性能和磨损性能都达到最优。     

二硫化钼固体润滑球轴承的真空摆动特性

以常用精密二硫化钼固体润滑球轴承为研究对象,采用摆动试验装置,在真空环境中研究其在小角度往复运动工作模式下的摩擦力矩、磨损形貌、使用寿命。结果表明:在真空环境中小角度往复运动模式下,二硫化钼固体润滑轴承摩擦表面不能够形成有效的转移润滑膜,因而轴承摩擦力矩增大,滚道磨损严重,且在一定范围内摆动角度越小、摆动频率越高,轴承的摩擦力矩增加越大、滚道磨损越严重;工作在小角度往复摆动模式下二硫化钼固体润滑球轴承的运转寿命远小于同等接触应力条件下单向运转时的轴承运转寿命。     

二硫化钼改性水润滑尾轴承摩擦磨损性能研究

以橡塑复合材料为基体,将纳米和普通二硫化钼添加到基体材料中,制备一种水润滑橡塑复合尾轴承材料。通过试验探究复合轴承材料在不同载荷和转速下的摩擦磨损性能。试验结果表明:在相同载荷下,复合材料摩擦因数随着转速的升高先逐渐降低并最终趋于稳定,在相同转速下,复合材料摩擦因数随着载荷的升高而逐渐降低;复合材料摩擦因数随着二硫化钼添加量的增加先降低后升高,且纳米复合轴承材料的摩擦因数都要低于普通复合材料;二硫化钼改善了材料的摩擦性能,但没有改善材料的耐磨性;改性复合材料的磨损形式属于黏着和磨粒磨损。     

环-块摩擦副条件下纳米二硫化钼的摩擦学性能

由硫化钠和钼酸钠水溶液反应生成三硫化钼沉淀，将三硫化钼脱硫，制得了粒径为20-30nm的纳米MoS2颗粒。利用MM-200摩擦磨损实验机测定了纳米MoS2作为N46机械油添加剂的摩擦学性能。结果表明，纳米二硫化钼比普通二硫化钼具有更好的抗磨性能。其机制为纳米二硫化钼比普通二硫化钼更容易发生摩擦化学反应，形成了富含硫和钼的润滑膜，而起抗磨作用。     

固体润滑涂层在干摩擦及有油条件下的摩擦磨损性能

采用MRH-3环块磨损试验机对FM-510二硫化钼润滑涂层在于摩擦及有油条件下进行了摩擦磨损性能的考察和评价,评价结果表明：该涂层在干摩擦条件下具有低的摩擦系数、高的承载能力和长的耐磨寿命,摩擦系数随负荷增高而降低,随速度提高也降低。摩擦偶对双面涂膜比单面涂膜有更长的耐磨寿命,速度低时涂层的磨耗小,寿命长,可满足特定条件下的干摩擦工作要求,在有油润滑条件下二硫化钼基的FM-510润滑涂层可显减轻对偶磨损程度,摩擦系数比单独使用油润滑时大大降低。在难以形成连续的流体润滑薄膜,亦即不能形成流体动力润滑的情况下。摩擦偶对涂敷固体润滑涂层是解决其润滑问题的有效方案。     

含氢类富勒烯碳薄膜制备及超滑性能研究进展

类富勒烯碳薄膜是一种由弯曲石墨烯镶嵌的非晶网络复合结构,正是由于这种弯曲石墨烯结构(类富勒烯结构)的存在,赋予了薄膜高的硬度,优异的弹性恢复和超低摩擦性能(摩擦因数为0. 002～0. 009)。综述含氢类富勒烯碳薄膜制备方法、纳米结构调控机制、超低摩擦学机制及后处理对薄膜摩擦学性能的影响;探讨含氢类富勒烯碳薄膜在汽车发动机方面的应用,指出其可有效降低发动机部件的摩擦磨损,有利于发动机的节能减排;总结氢类富勒烯碳薄膜未来工程应用的潜在挑战,指出类富勒烯碳薄膜虽在可控范围内具有超滑性能,但未来如何实现全工况范围超滑和固油复合超滑将是一个主要研究方向。     

自制二硫化钼微球在500SN中的摩擦磨损性能研究

将自制的表面修饰的二硫化钼微球（MS-MoS2）和商业级胶体二硫化钼（CC-MoS2）分别添加到基础油500SN中，用四球摩擦磨损机和SRV微动摩擦磨损试验机对比研究了不同润滑体系的极压性能和抗磨减摩性能。结果表明：萃取剂Cyanex 301对MoS2具有良好的表面修饰作用；添加MoS2能够有效改善基础油的极压性能和抗磨减摩性能；在试验力为400N，最佳添加量分别为0．10％和0．25％（质量分数）时，500SN＋MS．MoS2和500SN＋CC-MoS2相对500SN的摩擦因数分别降低了17．2％和12．3％，磨损体积分别降低了44．8％和17．2％。     

润滑脂对膨胀管材料摩擦性能的影响

膨胀管膨胀过程中的摩擦影响到膨胀的难易程度和胀后套管的性能,选择一种合适的润滑介质降低膨胀过程中的摩擦因数对膨胀管技术来说非常重要。使用摩擦模拟实验的方法,研究在二硫化钼锂基脂、铅基润滑脂和没有润滑脂的3种条件下普通N80膨胀管材料的摩擦性能,使用扫描电子显微镜对不同载荷下试样的磨损表面进行分析,并讨论不同润滑条件下的磨损机制。结果表明,润滑脂的加入可以显著降低膨胀过程中膨胀管材料的摩擦因数和磨损量,磨损机制也从原来的磨粒磨损变成黏着磨损,铅基润滑脂由于摩擦因数更低具有最好的润滑效果,可以显著提高膨胀管材料在膨胀过程中的耐磨性能。     

固化剂对黏结润滑涂层摩擦学性能的影响

以环氧树脂为胶黏剂,聚四氟乙烯、石墨、二硫化钼为固体润滑剂,采用二氨基咪唑三嗪络合物(HT110)和二氨基二苯砜(DDS）2种不同的固化剂制备黏结固体润滑涂层,并在HDM-20端面摩擦磨损试验机上考察2种黏结固体润滑涂层在干摩擦条件下的摩擦磨损性能。结果表明：使用HT110固化剂可以获得更合适的表面组织结构,使黏结固体润滑涂层具有更好的减摩性,更高的耐负荷极压性;固化剂含量对涂层性能的影响显著,当HT110固化剂质量分数为6%~8%时,黏结润滑涂层的摩擦因数最低,具有最好的耐磨和高承载性能。     

纳米二硫化钼作为润滑油添加剂的摩擦学性能研究

研究纳米二硫化钼作为润滑油添加剂的摩擦学性能。以不同的表面活性剂和不同的超声波分散时间制备纳米二硫化钼润滑油,考察表面活性剂和超声波分散时间对纳米二硫化钼分散稳定性的影响。采用四球机和描电镜考察纳米二硫化钼在润滑油中的摩擦学性能。结果表明,2%油酸表面活性剂和超声波分散30 min可有效提高纳米二硫化钼在润滑油中的分散稳定性,纳米二硫化钼在润滑油中具有良好的抗磨性能、减摩性能,特别是0.01%二硫化钼在润滑油中的抗磨性能和高负荷下的减磨性能更为突出。     

添加油酸修饰的纳米Fe3 O4粒子润滑油的摩擦学性能研究

利用化学共沉淀法制备了平均粒径为10nm、油酸表面修饰的Fe3O4粒子，并对其作为润滑油添加剂的摩擦学性能进行了研究。试验结果表明，添加油酸修饰的纳米Fe3O4粒子的润滑油表现出了较好的抗磨减摩性能，但是，纳米粒子的添加量有一最佳值。与基础油相比，添加纳米Fe3O4粒子润滑油的摩擦因数最大降低了26％，磨损量降低了28％。在摩擦磨损过程中，添加纳米Fe3O4粒子润滑油的摩擦力矩的变化表现出了时间效应。添加纳米Fe3O4粒子润滑油摩擦磨损后的磨痕表面比基础油摩擦磨损后的磨痕表面光滑，可以推测，纳米Fe3O4粒子对摩擦表面的抛光作用提高了润滑油的摩擦学性能。     

润滑油中CuS纳米粒子的摩擦学性能研究

本文用合成工艺简单、成本低廉、易于工业化生产的液相法制备了CuS纳米粒子,并对该粒子在润滑油中的摩擦学性能进行了研究。结果表明,CuS纳米粒子加入润滑油中,能极大地提高基础油的抗磨减摩性能。     

重型汽车中桥减速器润滑油中磨损颗粒分析

重型汽车中桥减速器在工作过程中其摩擦副接触表面因相对运动而产生的磨损颗粒进入润滑油中,导致润滑油性能下降;磨损颗粒随润滑油进入摩擦副接触表面,摩擦副磨损加剧。根据重型汽车的运行特点,每隔一定里程数对减速器润滑油进行取样,综合分析在用润滑油中磨损颗粒物的大小、形貌及成分。结果表明：减速器在用润滑油中磨损颗粒主要成分是铁屑和铜屑,磨损颗粒主要来自于球面垫片（铜）及其配副的摩擦以及齿轮副间的摩擦。具体分析磨损颗粒产生过程及形成机制,为重型汽车中桥减速器中运动摩擦副的设计及制造提供理论依据。     

Tribological properties of nickel-based self-lubricating composite at elevated temperature and counterface material selection

Solid lubricating materials are necessary for development of new generation gas turbine engines. Nickel-based self-lubricating composites with graphite and molybdenum disulfide as lubricant were prepared by powder metallurgy (P/M) method. Their tribological properties were tested by a MG-2000 high-temperature tribometer from room temperature to 600 °C. The structure of the composite was analyzed by XRD and worn surface morphologies were observed by optical microscope. The effects of counterface materials on tribological behavior of composites were investigated. It was found that chromium sulfide and tungsten carbide were formed in the composite by adding molybdenum disulfide and graphite, which were responsible for low-friction and high wear-resistance at elevated temperatures, respectively. The average friction coefficients (0.14–0.27) and wear rates (1.0–3.5 × 10⁻⁶ mm³/(N m)) were obtained for Ni–Cr–W–Fe–C–MoS₂ composite when rubbed against silicon nitride from room temperature to 600 °C due to a synergetic lubricating action of graphite and molybdenum disulfide. The optimum combination of Ni–Cr–W–Fe–C–MoS₂/Ni–Cr–W–Al–Ti–C showed lower friction than other counter pairs. The graphite played the main role of lubrication at room temperature, while sulfides were responsible for low friction at high temperature.     

Zinc and molybdenum dithiocarbamates — antioxidant additives

Zinc and molybdenum dithiocarbamates are used as effective additives in lubricants of various types. Following earlier reported investigations on their antifriction and antiwear properties, it was found that zinc and molybdenum dithiocarbamates had some antioxidant capabilities, so investigations have been carried out to compare the influence of zinc and molybdenum dithiocarbamates and dithiophosphates on the antioxidant properties of lubricating oils over a wide range of temperatures. The antioxidant activity of a number of synthesised additives was determined by a kinetic method in model conditions; the antioxidant properties of these additives were also compared in more severe conditions. It was found that the effectiveness of metal dithiocarbamates depends on the oxidation test conditions. The influence of zinc and molybdenum dithiocarbamates on the antioxidant properties of lubricating oils increases in the presence of zinc dithiophosphate and calcium phenate.     

用SRV试验机评价柴油机油摩擦磨损性能

采用SRV 4型摩擦磨损试验机为试验平台,以某商用车公司提供的发动机缸套-活塞环截取件作为摩擦副试验件,以15W-40 CF-4和15W-40 CI-4发动机油为润滑介质,建立评价柴油机油摩擦磨损性能的模拟试验方法,并使用该方法对油品配方中减摩剂的区分性及不同材质活塞环与润滑油的适配性等进行考察。试验结果表明:建立的模拟试验方法能较好地区分出具有优异抗磨性能的柴油机油,同样对油品配方中减摩剂和不同材质活塞环与润滑油适配性等有着较好的区分性,可以作为润滑油品开发者和OEM汽车厂家对油品配方开发和摩擦副材质筛选的模拟评价手段。     

黏结石墨基固体润滑涂层在油介质中的摩擦学性能

为了探讨聚酰亚胺黏结石墨基固体润滑涂层在油介质中的摩擦学性能及其作用机制,采用MHK-500型摩擦磨损实验机对聚酰亚胺黏结石墨基固体润滑涂层在4种油介质(RP-3煤油、0#柴油、液体石蜡和SG 15W-40机油)中的摩擦磨损性能进行评价,并对其机制进行初步的探讨。结果表明:与干摩擦相比,涂层在4种油介质中的摩擦学性能都有显著提高,其中在柴油介质中涂层的抗磨性能提高最为突出,可能的原因是中等黏度的柴油介质在摩擦界面能形成足够厚的油膜,又能对涂层进行有效的冷却;同种油介质中,涂层在高速(2.56 m/s)、低载(1 120 N)下的耐磨性能明显优于低速(1.54 m/s)、高载(2 120 N)下的耐磨性能。     

Comparison of boundary lubrication films formed under four‐ball friction test conditions with different AW/EP Additives‐an X‐ray photoelectron spectroscopy study

The antiwear and extreme‐pressure properties of six different types of additive (molybdenum dialkyldithiophosphate, dibenzyl disulphide, molybdenum dialkyldithiocarbamate, zinc dialkyldithiophosphate, chlorinated paraffin wax, and triaryl phosphate) were evaluated by standard four‐ball friction and wear tests. This was followed by scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), and X‐ray photoelectron imaging (XPI) analyses of the worn surfaces to determine the structure of the boundary lubrication film and the mechanism of the tribochemical reaction occurring during the friction process. The presence of the additives in the base oil significantly increased the weld load and drastically reduced the wear‐scar diameter, suggesting antiwear and extreme‐pressure properties of the additives. The enhanced antiwear and loadcarrying capacity of the additive‐containing oils was attributed to the formation of a complex boundary lubrication film formed between the surfaces during the friction process as a result of the tribochemical reaction. The antiwear and extreme‐pressure properties of the additives were explained based on the XPS data. The studies indicated that the lubricating properties of the additives depend on their chemical nature and reactivity with metal surfaces.     

The Synergetic Effects of Surface Texturing and MoDDP Additive Applied to Ball-on-Disk Friction Subject to Both Flooded and Starved Lubrication Conditions

This paper reports a novel work on the synergetic effects of microscale surface texturing and lubricant friction modifier additive of molybdenum dialkyldithiophosphate (MoDDP) subject to both flooded and starved lubrication conditions. The experiments were performed on reciprocating ball-on-disk friction in GTL8 base oil with and without MoDDP. In the flooded lubrication condition, the test results demonstrated that the presence of the MoDDP additive contributed to lower friction coefficients and also more pronounced effect of surface textures on friction than in the case of the bare base oil. In the starved lubrication experiments, textured and texture-free surfaces in the oils with and without MoDDP additive were tested until an abrupt rising of friction coefficient was detected. The results showed that the magnitude of friction coefficient before terminating each test was the almost same for various tests, while the endurance time in different test conditions was significantly different. The textured surface exhibited longer endurance time than the texture-free surface, especially when the MoDDP additive was used. The mechanism of the synergetic effects of surface textures and MoDDP additive has been discussed based on the experimental observations in the following sections. This study provides a new idea for the application of surface texture in boundary lubrication when lubricant additive is contained in the lubricating oils.