Application of fullerene-added nano-oil for lubrication enhancement in friction surfaces

This paper presents the friction and antiwear characteristics of nano-oil composed of refrigerant oil and fullerene nanoparticles in the sliding thrust bearing of scroll compressors. The nano-oil was evaluated using a sliding thrust bearing tester. The friction coefficient of fullerene nano-oil at the lower normal loads (<∼1200 N) under the fixed orbiting speed (∼1800 rpm) was ∼0.02, while that of pure oil was ∼0.03, indicating that the fullerene nanoparticles dispersed in the base refrigerant oil improved the lubrication property by coating the friction surfaces. However the difference between friction coefficients for both nano-oil and pure oil was found to be negligible at higher normal load conditions (>∼1200 N), indicating that the nanoparticles in the base oil have little effect on the enhancement of lubrication between the friction surfaces. The friction coefficient of nano-oil at various speeds of the orbiting plate in the sliding thrust bearing was found to be less than that of pure oil over the entire orbiting speed ranges between 300 and 3000 rpm. This is presumably because fullerene nanoparticles, which were inserted between the friction surfaces, improved the lubricating performance by increasing the lubricant oil viscosity and simultaneously preventing direct metal surface contacts.     

Enhancement of Lubrication Properties of Nano-oil by Controlling the Amount of Fullerene Nanoparticle Additives

In this article, the tribological properties of fullerene nanoparticles-added mineral oil were investigated as a function of volume concentration of fullerene nanoparticle additives (e.g., 0.01, 0.05, 0.1, and 0.5 vol.%). The lubrication tests were performed at the disk-on-disk type tester under the various normal forces and fullerene volume concentrations. Tribological properties were evaluated by measuring the friction surface temperature and friction coefficient, and then interpreted in terms of Stribeck curves. At the same time the friction surfaces tested were evaluated by observing their SEM images, surface roughness, and AFM images. The results showed that the nano-oil containing the higher volume concentration of fullerene nanoparticles resulted in the lower friction coefficient and less wear in the fixed plate, indicating that the increase of fullerene nanoparticle additives improved the lubrication properties of regular mineral oil.     

Understanding the Role of Nanoparticles in Nano-oil Lubrication

A disc-on-disc type tester was used to examine the role of fullerene nanoparticles dispersed in a mineral oil-based lubricant. In the friction test, the friction coefficient of the disc specimen immersed in the nano-oil was significantly lower than that of the disc specimen immersed in the mineral oil. This suggests that the nanoparticles dispersed in mineral oil played the important role in the lubrication enhancement of nano-oil. A series of experiments in this study were carried out to delineate the two effects [i.e., direct effect (e.g., rolling/sliding/filming) and surface enhancement effect (e.g., mending/polishing)] of nanoparticles for nano-oil-based lubrication enhancement. The disc specimens immersed in the nano-oils during the friction test was removed, and then they were re-immersed in new mineral oil for an additional friction test. The direct and surface enhancement effect of nanoparticles was then visualised by the evolution of the friction coefficient of the disc specimen immersed in the mineral- and nano-oil. The results showed that the direct effect of nanoparticles was much more dependent on the magnitude of the applied normal load than the surface enhancement effect.     

纳米二氧化硅对锂基润滑脂摩擦学性能的影响

利用溶胶-凝胶法,以正硅酸乙酯为原料制备了纳米二氧化硅微粒,通过透射电子显微镜对其结构进行了表征,利用四球摩擦磨损试验机测定了添加不同含量纳米二氧化硅锂基润滑脂摩擦学性能,采用扫描电子显微镜观察磨损表面形貌。结果表明:制备的纳米二氧化硅是粒径为60 nm左右的球形微粒,具有很高的表面能和表面活性;纳米二氧化硅作为锂基润滑脂添加剂能够提高最大无卡咬负荷和烧结负荷,降低摩擦因数,添加量为2.0%(质量分数)时的润滑剂性能最好,相对应的钢球磨斑直径最小,摩擦因数最低。     

基于正交试验的含氮硼酸酯铝材轧制润滑油摩擦学性能研究

合成一种新型含氮硼酸酯铝材轧制润滑油添加剂,利用四球试验机考察添加含氮硼酸酯的铝材轧制润滑油的油膜强度、摩擦因数,通过显微镜观察磨斑形貌并测量磨斑直径。利用正交试验法评估极压剂含量、基础油种类、四球试验机载荷和转速对含氮硼酸酯润滑油摩擦学性能的影响,并通过多目标优化设计,对4种参数对铝材轧制润滑油摩擦学性能的强化效果进行综合研究。结果表明:各工艺参数对油样的摩擦学性能影响显著性由大到小依次为极压剂添加量、基础油种类、转速和载荷;经过多目标优化设计,得到的含氮硼酸酯铝材轧制润滑油强化工艺参数的最佳组合:极压剂质量分数为1.0%,基础油种类为D100,载荷为294 N,转速为1 200 r/min;通过极差、方差等分析,发现极压剂添加量和基础油种类对油样的摩擦学性能有显著影响。     

含硫化铜纳米粒子润滑脂的微动磨损性能研究

在微动磨损试验机上考察了含有硫化铜纳米粒子脲基脂的微动磨损性能。结果表明:硫化铜纳米粒子能显著降低微动磨损体积,随着纳米粒子含量增加,微动磨损量降低;在微动磨损后期纳米粒子的存在还能降低摩擦因数。低负荷下,润滑脂中硫化铜纳米粒子有利于降低微动磨损量;但在高负荷条件下,磨损量迅速增大,说明高负荷下微动磨损方式发生了变化。XPS分析表明,微动磨斑表面膜含有Cu、FeS等物质,说明硫化铜纳米粒子能显著降低微动磨损的原因在于纳米粒子化学性质非常活泼,在微动过程中容易与摩擦表面发生化学反应,形成具有保护性的沉积物膜和化学反应膜。     

Inconel718与硬质合金摩擦磨损特性的实验研究

利用UMT-2多功能摩擦磨损试验机对镍基合金Inconel 718与硬质合金刀具对偶时的摩擦磨损特性进行研究,揭示法向载荷和滑动速度对摩擦副摩擦因数的影响,通过SEM观察试样摩擦形貌并分析磨损机制.研究结果表明:摩擦副的摩擦因数随着法向载荷的增大而减小,随滑动速度的增大而增大;Inconel 718镍基合金与硬质合金对偶时的磨损机制主要为黏着磨损、磨粒磨损和氧化磨损.     

废润滑油/再生润滑油的摩擦学性能

使用可见分光光度计初步评价实验室自主研发工艺处理得到再生润滑油的质量,采用四球摩擦磨损试验机考察再生润滑油的摩擦学性能并与废润滑油、新润滑油进行对比研究,借助扫描电子显微镜对磨斑表面形貌进行观察分析,对再生润滑油的抗磨减摩与润滑机制进行探讨。结果表明,废润滑油摩擦学性能严重下降,较新润滑油摩擦因数升高26%以上,磨斑直径增大58%以上;再生润滑油表现出了优良的减摩抗磨性能,较废润滑油摩擦因数能够降低25%,磨斑直径可减小50%左右,基本达到了新润滑油的水平。     

润滑剂对轮轨摩擦与磨损的影响

利用MMS-2A磨损试验机模拟轮轨系统在润滑油、二硫化钼锂基脂、植物油和石墨钙基脂4种润滑剂润滑下的摩擦与磨损行为,研究润滑剂对轮轨副摩擦、磨损特性的影响.结果表明:与干态相比,4种润滑剂均使摩擦副的摩擦因数减小,表面磨痕深度减小,磨损量降低,其中石墨钙基脂的减摩和抗磨效果最好;试验结束后,轮轨试样接触表面的硬度均有不同程度的增加,其中涂有石墨钙基脂的轮轨试样的表面硬度增加最小.     

Tribological investigation of layered sodium silicate as lubricant additives prepared by freezing titration ion exchange

Two layered sodium silicate products were prepared using a new ion exchange method called the freezing titration ion exchange. The tribological properties of the ion exchange products as additives in mineral oil were evaluated using a four-ball tester. The products exhibited excellent friction behavior when used as additives in mineral oil. When 1 wt% was added, the tribological properties of the oils improved: the maximum non-seizure loads increased by over 27% and the wear scar diameter and friction coefficient decreased by over 50% and 25%, respectively. The friction and wear behaviors of the silicates were better than those of the typical lubricant additives.     

不同载荷下水润滑高分子材料磨损机制的试验研究

为了研究载荷对新型水润滑高分子轴承材料磨损机制的影响,在CFT-1型摩擦磨损试验机上对该材料进行不同载荷下的无/有水润滑摩擦磨损试验,通过考察试样的摩擦因数、磨痕和磨损表面形貌,分析该材料的磨损机制。结果表明:在无水润滑条件下,该材料的摩擦因数随着载荷的增加呈现先降低后逐渐上升的变化趋势,磨损表面均出现塑性变形和撕裂脱落现象,磨损机制主要为黏着磨损,其中随着载荷的增大表面塑性变形趋于严重,而表面撕裂脱落在中等载荷下较为轻微,在低载荷和高载荷下较为严重;在水润滑条件下,该材料的摩擦因数随着载荷的增加也呈现出先下降低后急剧上升的趋势,磨损表面未发生塑性变形和撕裂脱落,但出现脱落的磨粒和犁沟,磨损机制主要为磨粒磨损,其中在中等载荷下,表面脱落的磨粒少、犁沟细小而浅,在低载荷和高载荷下表面脱落的磨粒多、犁沟深。     

抗磨添加剂对不同服役阶段润滑油摩擦学性能的影响

采用黏度测试仪测定新油及3种不同服役阶段润滑油的黏度,采用UMT-II摩擦磨损试验机考察其摩擦学性能,并同时考察3种在用润滑油添加抗磨添加剂后的摩擦学性能。研究结果表明:润滑油的黏度随着运行里程数的增加呈现先降后增的趋势;随润滑油运行里程数的增加,润滑油的摩擦因数增大,导致试验钢球的磨损量也增加;抗磨添加剂对不同服役阶段的润滑油的抗磨性能影响程度不同,在磨合磨损期和正常磨损期,加入抗磨添加剂后并不能改善润滑油的抗磨性能,而在异常磨损期,抗磨添加剂的加入可较好地改善润滑油的抗磨性能。     

Friction and Wear Behavior of Steels under Different Reciprocating Sliding Conditions

The friction and wear behavior of ISO 100Cr6 steel ball sliding against conventionally hardened carbon and low-alloy steels was studied. The effect of hardness, hardening capacity, normal load, and sliding speed on the coefficient of friction and friction energy was investigated. Friction tests were carried out, without lubrication and under ambient conditions, on a reciprocating friction tester in which a ball-on-flat contact configuration was adopted. The results showed that there is a relative tendency for the friction properties to decrease with increased hardening capacity and decreased hardness. The results showed that increasing normal load decreases the coefficient of friction for the two steel nuances. However, increasing sliding speed increases the coefficient of friction of low-alloy steel and decreases the coefficient of friction of carbon steel. The oxidation of wear debris influences the wear mechanisms and friction behavior.     

短切玻璃纤维增强尼龙材料的摩擦与磨损

在环块式磨损试验机上研究了载荷、速度以及润滑介质等因素对自制短切玻璃纤维增强尼龙材料摩擦学行为的影响 ,利用扫描电镜对其磨损机理进行分析。发现 :材料的摩擦系数随载荷的增加而下降 ,达到最小值后 ,又随载荷的增加而持续上升 ,随着速度的增加 ,材料的摩擦系数增加 ;材料的磨损量则随载荷、速度的增加而持续增加 ;材料的磨损以粘着、疲劳为主。在润滑条件下 ,复合材料的摩擦系数大大降低 ;油润滑条件下 ,材料基本无磨损 ,但水润滑条件下 ,材料的磨损量反而比干摩擦条件下大。     

新型含N杂环化合物的合成及其摩擦学性能研究

合成了一种新型含N杂环化合物添加剂,利用红外光谱仪定性分析了其结构,利用热重试验和油溶性试验考察了其热稳定性及其对液体石蜡基础油的感受性,利用四球和HQ-1环块试验机考察了其摩擦学性能。结果表明其具有较好的热稳定性及其对液体石蜡基础油良好的感受性,能降低长磨磨斑直径和减小摩擦因数,有效提高基础油的摩擦学性能。     

38CrSi自配副的摩擦磨损性能

采用自制的销盘式摩擦磨损试验机研究了38CrSi自配副干滑动时的摩擦因数、磨损率随滑动速度和载荷的变化规律;利用SEM观察了磨损面的微观形貌,分析了摩擦磨损机理。结果表明:其摩擦因数随着载荷和速度的增加而减小;磨损率随着载荷的增加而增大,随着速度的增加先增大后减小,和常用材料的磨损率随速度增加而增大的规律不同;磨损机理为磨粒磨损和粘着磨损。     

二烷基二硫代磷酸镧/铕混合稀土有机化合物在润滑油中的摩擦性能

合成了二烷基二硫代磷酸镧／铕混合稀土有机化合物(La／EuDDP)，加入到30^#齿轮油中，利用四球试验机考察了摩擦磨损性能。结果表明，La／EuDDP作为润滑油添加剂具有良好的抗磨性能和承载能力，并具有一定的减摩能力，加有该添加剂的30^#齿轮油PB值增加了128％，磨斑直径减少了50％以上。     

聚合十六烷氧基硼酸钾的合成及作为润滑油抗磨减摩添加剂的摩擦学性能

本文合成了一种含硼及钾的油溶性化合物-聚合十六烷氧基硼酸钾并将其用作润滑油抗磨减摩添加剂,用四球及环块摩擦试验机研究了它的摩擦学性能.结果发现:500SN基础油的抗磨性能得到明显改善,其承载能力明显提高,摩擦系数明显降低,有—最佳添加剂含量,超过此量,油品的承载能力不升反降.将磨斑分别在石油醚及蒸馏水中用超声波清洗后用扫描电子显微镜表征,结果发现磨斑表面存在有含硼沉积物.聚合十六烷氧基硼酸钾在表面发生了摩擦化学反应,如分解、缩合等,这些反应产物形成了一层具有抗磨减摩性能的膜.     

A New Tribological Approach for Lubricated Sliding Contact of Pitted Metallic Curvature Cup

Interest in the development and application of plant-based lubricants for medical use is increasing. This study investigates palm oil lubricants as environmentally friendly and renewable resources to optimize the motion in an ergonomic simulated metal hip prosthesis with modification to the acetabular cup surface. Although metal hip replacements are extensively used, minimizing metal-on-metal friction and wear using safe lubricants requires further investigation. The main physical properties of palm kernel oil and palm fatty acid distillate are considered. The viscosity, wear scar, and coefficient of friction are compared to hyaluronic acid. A modified pin-on-disc tribometer simulates friction and wear on a 28-mm-diameter acetabular cup and microscopy image analysis is used to examine the wear scar. The physical properties of palm oil derivatives reduce friction and wear. In brief, the most significant results of this study include the effect of lubricant and number of pits on wear and friction coefficient. The contribution of this research work is to maintain stability and increase the lifetime of ergonomic metal hip implants.     

烷氧基硼酸锌的动态固体膜润滑及零磨损特性的研究

提出了动态固体膜润滑的概念,合成了烷氧基硼酸锌,评价了其作润滑油添加剂的摩擦学性能,采用改进的环-块摩擦磨损试验机利用电阻法测定了摩擦副之间的润滑状态,利用扫描电子显微镜（SEM）观察了磨斑形貌。实验结果表明：当负荷低于40 N、摩擦速度高于1.28 m/s时,电阻测定表明摩擦副之间被添加剂（烷氧基硼酸锌）产生的半固体膜所隔开,处于动态固体润滑膜润滑状态,并可实现零磨损。SEM观察到的磨斑表面形貌进一步证实了动态固体润滑膜的存在。该添加剂表现出了一定的抗磨减摩性能。