纳米材料在轴承润滑脂中的应用

纳米材料作为润滑油抗磨减摩添加剂的研究受到广泛关注，但纳米润滑添加剂在润滑脂领域中的应用起步较慢，本文从纳米润滑添加剂的种类、摩擦学性能方面介绍了纳米润滑添加剂的研究进展，展望纳米材料在轴承润滑脂中的应用。     

液晶降低机床爬行临界速度的研究

根据液晶的减摩作用，研究了液晶作为润滑添加剂在改善机床爬行状况，即降低其爬行临界速度方面的实际应用。选择了3种液晶，每种都按6种不同的浓度加入到N32（旧标准HJ20）机械油中，在M7130型平面磨床上进行了试验。试验结果表明，液晶作为润滑添加剂确实具有良好的防爬作用，且防爬效果与液晶种类及其添加浓度有关。     

论水溶性润滑添加剂的研究方法

在已知的油溶性润滑添加剂分子中，引入水溶性基团，可以改性成水溶性润滑添加剂，在一个分子中同时包含水溶性、吸附性、疏水性、反应性基团，是合成兼有油性剂和极压剂功能的高效水溶性润滑添加剂的方法。     

水溶性金属加工液添加剂的制备及其性能研究

综述了金属加工液的发展趋势，提出了制备水溶性润滑防锈添加剂的“组合化学”方法，制备了水溶性润滑防锈添加剂，并对其性能进行了评定。     

气缸套活塞环摩擦副上止点附近的低速润滑特性

针对柴油机气缸套-活塞环摩擦副在上止点附近的低速润滑问题,采用往复摩擦磨损试验方法,获得不同载荷、不同润滑介质条件下,速度对润滑特性的影响规律。试验结果表明:低速区域滑动速度的微小变化带来了上止点附近润滑特性的明显改变。当载荷为10 MPa,滑动速度小于0.4 mm/s时,润滑油中的添加剂ZDDP会显著减小摩擦力;滑动速度大于0.4 mm/s时,添加剂ZDDP对减小摩擦力的影响减弱。当载荷为20 MPa时,添加剂ZDDP在试验速度范围内会一直减小摩擦力。     

铝合金加工用水基切削液润滑性能的影响因素

使用攻丝扭矩实验方法研究铝合金加工用水基切削液润滑性能的影响因素。实验结果表明,稀释液pH值、乳液粒径对润滑性能的影响最为显著,基础油含量、润滑添加剂种类及含量等亦有明显影响;稀释液pH值越低、乳液粒径越大、基础油和合成酯含量越高,润滑性能越好;三羟甲基丙烷油酸酯、乙氧基化聚合酯、氯化石蜡、硫化脂肪酸酯等均为有效的铝合金加工润滑添加剂,但硫化烯烃润滑性能较差。     

两种不同润滑添加剂对车用二甲醚发动机性能影响的试验研究

开展了两种润滑添加剂对二甲醚发动机燃烧与排放特性影响的试验研究。结果表明:分别加入C100和R100这两种润滑添加剂后二甲醚发动机均可在宽广的转速和负荷范围内工作,其输出功率都可达到甚至超过原柴油机,但加入润滑添加剂R100时二甲醚发动机的输出功率、缸内最高爆发压力和最大压力升高率比加入润滑添加剂C100时的略高;加入两种不同润滑添加剂后二甲醚发动机都可以实现无烟燃烧,NOx、HC和CO排放相当。     

氮化硅添加剂对直齿轮弹流润滑的影响研究

润滑油主要由基础油和添加剂构成。润滑油的性能取决于添加剂的种类和成分。氮化硅作为润滑油添加剂,可以大幅提高润滑油的摩擦磨损性能。文章对添加了氮化硅润滑油的直齿轮副进行研究,建立了添加氮化硅后的弹流润滑数学模型,利用MATLAB求解并与传统弹流润滑模型比较,发现氮化硅添加剂可增大油膜厚度,并可有效降低摩擦磨损。     

润滑冷却液

润滑冷却液可分为两大类:一是有明显的润滑性能的油基润滑冷却液;一是冷却性能为主的水基润滑冷却液。1 油基润滑冷却液油基润滑冷却液主要用于低速和较大负荷加工硬钢、耐蚀钢、热强钢、铸铁和铜合金。为了获得所需性能的油基润滑冷却液,在矿物油基中加入各种油性添加剂,以改善润滑性能,提高切削区内的极压性。这些添加剂在常温下不表现自己,而在切削时将急剧产生活化作用,并促进切屑形成和排屑。添加剂的活性程度主要与被加工材料的种类及其硬度有关。     

润滑材料中减摩添加剂研究的进展

本文综述了国外发达国家为减小机械磨损而研制的用于润滑材料中的多种减摩添加剂的概况,介绍了国内润滑材料中减摩添加剂的研究进展,并对减摩添加剂的节能效果,试验结果的差异和经济效益问题提出几点看法。     

Recent trends in environmentally friendly lubricants

Many of the lubricants used in the world today cause environmental pollution through total‐loss applications, spillage, evaporation, and in other ways. To reduce this environmental damage, new lubricants that are rapidly biodegradable and ecologically non‐toxic have started to be developed and marketed. This paper discusses the introduction of environmentally friendly lubricants and their constituents, with particular emphasis on their environmental benefits, applications, the limits to their use, their technical performance characteristics, and relative cost aspects; many of these lubricants are based on vegetable oils and esters. Comparisons are also made in the paper with conventional mineral‐oil based materials.     

舷外机用环境友好润滑油及其生物毒性的研究

利用发光细菌作为受试生物对研制的舷外机用TC-W3环境友好润滑油生物毒性进行了试验研究。试验结果表明以三羟甲基丙烷酯(TMP)为主调制的基础油具有低生物毒性、高润滑性能等优点,而以传统矿物油为主的基础油生物毒性较高,大量添加不利于实现低生物毒性的环境友好指标。润滑油的生物毒性主要取决于其添加剂的生物毒性,而添加剂生物毒性差异很大,合理选用添加剂及其使用比例是研制环境友好润滑油的关键。通过对润滑油基础油和添加剂的筛选及配比试验,成功地研制出低生物毒性、可生物降解的TC-W3环境友好润滑油,经润滑性、生物降解性和生物毒性试验,各项指标均满足设计要求。     

Tribological degradation of two vegetable‐based lubricants at elevated temperatures

Renewable‐based lubricants are being considered as potential alternatives to petroleum‐based lubricants for various reasons, mainly increased environmental sensitivity. However, understanding the tribological performance of such vegetable‐based lubricants under elevated temperatures is critical for their industrial implementation. This study focuses on the friction and abrasion rate characteristics of soybean and sunflower base oils in comparison to a base mineral oil under sliding wear at elevated temperatures. It was found that the abrasion rate and friction were less severe for the vegetable‐based lubricants up to temperatures around 100°C. The observed performance of the vegetable‐based lubricants was verified using a kinetic reaction mechanism model of lubricant degradation. Copyright © 2007 John Wiley & Sons, Ltd.     

Study of the tribological behavior of S-(carboxylpropyl)-N-dialkyl dithiocarbamic acid as additives in water-based fluid

There has been a growing concern for the use of water-based fluids because of the worldwide interest in environmental issues. This has promoted the research and use of water-soluble additives as environmental friendly lubricants. A kind of potential water-soluble additive, S-(carboxylpropyl)-N-dialkyl dithiocarbamic acid was prepared in this work. The friction and wear behaviors of the synthesized compounds as an additive in water-based liquid were evaluated with a four-ball tester and a ring-on-block rig. The wear scar morphology of the ball and the chemical nature of the antiwear films generated on the steel counter face were investigated with scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It was found that the synthesized additives had excellent antiwear, load-carrying and extreme pressure performance. The additive reacted with the counter-face metal and generated a surface protective film consisting of FeS, FeS₂, FeSO₄ and an absorbed compound containing N and acid.     

Environmentally adapted lubricants,Part I. An overview

The requirement for environmentally adapted lubricants has begun to play an increasingly important role in many industrial applications, particularly in the last two decades. The present‐day requirements for biodegradable and eco‐friendly lubricants imply that lubricants have properties that can minimise, if not eliminate, negative environmental impact, such as contamination of soil and water, caused by lost lubrication, leakage and accidents. The dominant factors that have a direct impact on the environment and which characterise the lubricant and its chemical composition, are toxicity, bio‐accumulation and biodegradability. Biodegradability is perhaps the most important factor which determines the fate of lubricant in the environment. Various commercial, governmental, and regulatory initiatives exist that protect the interests of the consumer. Life cycle analysis can help in assessing the total environmental impact of lubricants. This paper reviews the essential requirements of environmentally adapted lubricants, i.e., chemical composition, eco‐toxicity, biodegradability, bio‐accumulation, and eco‐labelling schemes, and life cycle analysis.     

Ionic Liquid Lubricants: Basics and Applications

Interest in the tribological performance of ionic liquids (ILs) has increased significantly since they were first introduced as lubricants in 2001. The primary advantages of ILs over conventional lubricants lie in their better ability to form tribofilms, higher thermal stability, environmental friendliness, and adaptability to various applications. A remarkable reduction in friction and wear has been observed after the addition of ILs in oil- or water-based media and in grease, suggesting that ILs are promising candidate materials as neat lubricants as well as lubricant additives. Despite the relatively common utilization of ILs as lubricating media, their wider use is limited by their high cost and corrosive properties. This article provides a brief introduction to relevant IL structures and properties, focusing on recent applications of the materials in engineering tribology.     

Tribological behavior of tungsten-doped DLC coating under oil lubrication

Diamond-like carbon (DLC) protective films have received considerable attention in recent years. Beside tools and dies, diamond-like and related coatings are starting to find application in some highly stressed mechanical components, including bearings and gears. Several different gear tests show an increase in carrying load capacity or prolonged lifetime with tungsten carbide-doped DLC (W-DLC)-coated gears. The lubricants have been mostly commercially available gear oils that were primarily developed or tailored for ferrous materials and are probably far from optimal for amorphous W-DLC layers.In the present work, the influence of lubricant chemistry on the friction and wear in W-DLC-coated contacts was investigated using a reciprocating test device. The first six test lubricants were conventional non-inhibited API/ATIEL base stocks followed by selected test blends in combination with different surface-active single additives. Experimental results in coated contact have shown that for friction reduction performance, additives are not necessary, while wear resistance is related with the chemistry of the lubricant. It may be concluded at this stage that different mechanisms of friction-induced interaction between lubricants and W-DLC-coated layers are possible.     

The influence of base oil properties on the efficiency of action of ZDDP-type additives

This paper deals with the analysis of the influence of base oil viscosity on the ability of ZDDP-containing lubricants to form protective layers (especially antiwear layers). The chemical structure of additives used was characterised according to their thermal stability, determined by differential scanning calorimetry (DSC). The additives were added to base oils of various viscosities. The prepared lubricants were tested using a four-ball machine, and analysed by DSC. The relationships between base oil viscosity and seizure load (P_t), weld load (P_w) and DSC test results are presented and discussed. The mechanism of interaction between ZDDP and the base oils was analysed by the use of a mathematical model.     

Influence of fatty acid composition on the tribological performance of two vegetable‐based lubricants

In light of diminishing natural resources, global climatic change and increased environmental sensitivity, renewable‐based lubricants are being considered potential alternatives to petroleum‐based lubricants. Understanding the tribological performance of vegetable‐based lubricants in relation to their chemical composition is essential for their industrial implementation. This study focuses on the friction and abrasion rate characteristics of soybean and sunflower oils in comparison to a base mineral oil under sliding wear at ambient conditions for various applied loads. It was found that the abrasion rate and friction were the least severe for the soybean, followed by the sunflower oil. The observed trends were attributed to differences in their fatty acid compositions, in particular, a lower percentage of linoleic and oleic acids within the soybean oil. Copyright © 2007 John Wiley & Sons, Ltd.     

Tribological properties of linear phosphazene oligomers as lubricants

The friction and wear behavior of a steel-on-steel contact lubricated by two novel synthetic linear phosphazene oligomers with different side branches and by perfluoropolyethers (PFPE) was comparatively investigated on an oscillating friction and wear tester. The thermal stability of the lubricants was investigated by means of thermogravimetric analysis. The worn surfaces were analyzed by means of scanning electron microscopy, energy-dispersive spectrometry, and X-ray photoelectron spectroscopy. It was found that the two synthetic linear phosphazene oligomers were more effective than PFPE in increasing the wear-resistance of the steel-on-steel frictional pair. The phosphazene oligomer having aromatic rings had better friction-reducing ability and higher thermal stability, and that having fluoropolyether gave higher load-carrying capacity. Tribochemical reaction was involved in the sliding of steel against steel under the lubrication of the lubricants, with the generation of a protective layer composed of inorganic fluoride FeF₂ and organic compounds consisting of C, F, O, N and P. The protective layer originated from the tribochemical reaction together with the adsorbed boundary lubricating layer containing organic compounds played an important role in improving the friction and wear behavior of the steel-on-steel system.