不同极压抗磨剂在磨损条件下的膜特征

本文选择了磷酸三甲酚酯（ＴＣＰ）,硫代磷酸三苯酯（ＴＰＰＴ）和２－巯苯并噻唑（ＭＢＴ）三种酯类润滑油常用的极压抗磨剂进行四球磨损试验,并用俄歇电子能谱（ＡＥＳ）对磨损试验后得到的磨斑进行表面膜的表层和深层剥离分析,试验发现磨斑上的表面膜的组成和厚度与四球试验得到的润滑性能有良好的对应关系。     

A study of the synergistic effect of a triazine‐dithiocarbamate derivative with tcp in vegetable oil

A novel, potential ashless S—N‐style additive, 2‐(N,N‐dibutylamino)‐4,6‐bis‐(dibutyldithiocarbamate)‐1,3,5‐triazine (DBTT), was synthesised and its synergistic tribological effect with a traditional additive, tricresyl phosphate (TCP), in rape seed oil was evaluated using a four‐ball tester. The results show that the load‐carrying capacity of the vegetable oil could be improved greatly by the presence of the TCP and/or DBTT additives; at certain mass ratios TCP and DBTT show a good synergistic effect in improving the tribological performance of the base oil. The elemental composition and chemical nature of antiwear films generated at a steel interface were investigated using Kevex energy dispersive X‐ray analysis and X‐ray photoelectron spectroscopy. Scanning electron microscopy was also used to study the rubbed surface morphology. It was found that FeS, organosulphur compound, sulphate, phosphate, and nitrogen‐containing compounds were present in the complex boundary lubrication film.     

一种硫磷氮衍生物在菜籽油中的摩擦学研究

通过Mann ich合成了2种有机环胺的硫磷酸酯衍生物,在四球摩擦磨损试验机上研究了它们作为菜籽油添加剂的摩擦学性能。实验结果表明,该类化合物具有良好的极压抗磨性能,能提高菜籽油的极压抗磨性能。通过用X-射线光电子能谱(XPS)分析了钢球磨损表面典型元素的化学状态,显示在摩擦过程中,钢球表面形成了一层含硫、磷无机膜和含氮的有机膜。     

Preparation of borate ester and evaluation of its tribological properties as an additive in different base oils

N‐containing borate ester (MEBE) with five‐member ring structure as a lubricant additive was synthesised. The tribological properties in liquid paraffin (LP), poly‐alpha‐olefin (PAO) and dioctyl sebacate (DOS) were evaluated, and the action mechanisms in different base oils were also explored. It was found that as‐synthesised borate ester possesses excellent antiwear performance in LP and PAO. XPS analysis suggests that the additive forms a protective film on the rubbing surfaces which is composed of BN, Fe₂O₃, polyoxyethylene ether and N‐containing organic compounds. The inorganic and organic protective films in the metal surface effectively improve the antiwear ability of the base stock. However, when the additive MEBE was introducted into DOS base oil which is prone to adsorbing to the metal surface because of the high polarity of DOS, it influences the compactness of the film formed by the DOS, resulting in weak antiwear property. Copyright © 2016 John Wiley & Sons, Ltd.     

The effect of the addition of phosphate esters to paraffinic base oils on their lubricating performance under sliding conditions

Using a modified Timken machine, the effect of the addition of different phosphate esters to paraffinic base oils on their lubricating performance was investigated. The aryl phosphate ester tricresyl phosphate (TCP) has a greater resistance to scuffing than the alkyl phosphate ester trioctyl phosphate (TOP) when used as a lubricant. In contrast, base oils containing TOP are superior to those containing TCP, although phosphate esters are effective only in base oils of higher viscosity than the esters.The lubricating performance of high viscosity base oils containing TOP is improved by coupling the ability of TOP to form a beneficial surface film with the ability of the base oils to build up thick oil films. The addition of TCP, which has a higher adsorption ability but a lower reactivity than TOP, seems, however, to prevent the formation of the oxide film which is formed with base oils alone owing to the marked ability of TCP to adhere to a metal surface. In addition, because of the low reactivity of TCP, iron phosphate is hardly formed. Consequently, the addition of TCP increases the scuffing load of the base oils but has the disadvantage of increasing the coefficient of friction.     

Tribofilms generated from ZDDP and DDP on steel surfaces: Part 2, chemistry

The chemical constitution of tribofilms, generated from zinc dialkyldithiophosphate (ZDDP) and ashless dialkyldithiophosphate (DDP), has been examined by X-ray Absorption Near Edge Structure (XANES) spectroscopy. The identification of spectral features and interpretation of the results for P, O, Fe, and S species are given, allowing an overall mechanism to be deduced. The role of Fe in these films was investigated in some detail using P L-edge, O K-edge and Fe L-edge XANES spectra. From the P L-edge XANES spectra, the DDP films are uniformly very short chain iron polyphosphates. In contrast, the ZDDP films are formed initially as short chain polyphosphates; but after more rubbing, a bilayer phosphate film is formed with long chain Zn polyphosphates on the surface and shorter chain in the bulk of the film. The O K-edge XANES spectra show that there is, as expected, more Fe in the DDP phosphate films than in the ZDDP phosphate films. The S K-edge spectra of ZDDP films show the presence not only of ZnS as previously observed, but also the presence of FeS for the first time in the early stages of film formation. The predominant S species in the DDP films is FeS.     

硫代磷酸三苯酯在季戊四醇酯中摩擦学性能及作用机理的研究

使用四球试验机，Falex摩擦试验机，铁谱技术和俄歇电子能谱技术考察了硫代磷酸三苯酯（TPPT）在季戊四醇酯中的摩擦学性能，研究表明：硫代磷酸三苯酯是良好的极压添加剂，很小的添加量就能起到良好的抗极压作用；而起抗磨作用时，必须满足一定添加量的要求，这是因为TPPT是必须在一定的高温下才能起作用的添加剂，在极压试验条件下，因摩擦产生的温升比常磨试验要大，因此TPPT的感受性更好，文章最后对TPPT的作用机理也进行了一定的推测。     

表面修饰FeS纳米微粒的研究(Ⅱ)--摩擦学特性研究

用四球摩擦磨损试验机考察了二烷基二硫代磷酸（DDP）修饰FeS纳米微粒作为润滑油添加剂的摩擦学行为.结果表明,DDP修饰FeS纳米微粒在极低的添加量时即具有良好的抗磨效果,但不能降低基础油的摩擦因数;磨损表面分析表明钢球表面形成了边界润滑膜,使摩擦学性能得到明显改善.     

Influence of metallic and oxidized iron/steel on the reactivity of triphenyl phosphorothionate in oil solution

The influence of metallic and oxidized iron/steel on the reactivity of triphenyl phosphorothionate (TPPT) in oil solution at 473 K was investigated by means of FT-IR, NMR and XPS. The FT-IR and NMR results show that the degradation of TPPT was catalyzed by metallic and oxidized iron powder and started with the breakage of the PS bond to form triphenyl phosphate (TPP). The results of the XPS sputter depth profile show the multilayer structure of the thermal film formed on 100Cr6 steel filings immersed for 72 h in TPPT solution heated at 473 K.     

二烷基二硫代磷酸镧的摩擦化学研究

以稀土元素的摩擦学应用为出发点,用异辛醇、La 2O 3和P 2S 5为原料合成出一种新型油溶性润滑油极压抗磨剂——二烷基二硫代磷酸镧（LaDDP）,对其减磨抗磨性能进行考察,同时还用扫描电子显微镜、X射线光电子能谱仪和俄歇电子能谱仪对边界润滑状态下形成的磨斑和表面膜元素组成及化学状态进行了分析。结果表明：这种添加剂在给定试验条件下使ISOVG68油的摩擦因数明显降低和卡咬负荷提高2.2倍,减摩抗磨性能比二烷基二硫代磷酸锌（ZDDP）好,主要原因是在摩擦过程中发生摩擦化学反应生成了由La、La 2O 3、FeS、硫酸盐和磷酸盐组成的边界润滑膜和镧渗透层。最后,用质谱仪模拟了LaDDP的摩擦分解过程,提出了其摩擦化学反应机理。     

Tribological Performance of EP Lubricants with Phosphorus-Based Additives

Lubricants containing additives that protect mechanical components against extreme pressure by reducing friction and wear are known as extreme pressure (EP) lubricants. In the current study, phosphorus-based EP lubricants with different additives (amine phosphate and phosphate ester) were tested in a steel ball-on-disc assembly under different EP conditions. The phosphate ester–steel interaction resulted in significantly higher wear and marginally lower friction than the amine phosphate–steel interaction. The tribological performance (especially wear) depended on the contact conditions. The tribofilm that formed on the steel surface with both EP lubricants consisted of organic compounds, oxides, and phosphates. The greater formation of the wear-resistant iron phosphate for the amine phosphate–steel interaction resulted in lower wear. The friction and wear performance for both EP lubricants depended upon surface roughness parameters along with the compounds that formed in the tribofilm.     

Effects of Sulfur Additive EP in Ester Coolants during Friction with CBN

A study was undertaken to investigate the effects of the EP additives during tribological tests using a CBN tool against steel. Ester oil with and without sulfur additive were used as lubricants in a tribometer. Tribochemical interactions between the S additive and steel have been investigated under boundary lubrication conditions by SEM and EDX analysis. The relative abundance of different elements on the surface of the CBN tools, which are present in the workpiece material such as Fe (iron) and Cr (chromium), suggests that adhesion occurred when the ester oil without sulfur additive was tested. Tribochemical interactions between the additive and the steel could be observed when using the ester oil containing the sulfur additive. These interactions contribute to the formation of a uniform layer on the CBN tool. This layer is composed by S (sulfur), Fe, and O (oxygen). The presence of these elements indicate that FeO (iron oxide) and FeS (iron sulfide) were formed.     

Tribological properties and hydrolysis stability study of benzothiazole borate derivative

A novel borate ester derivative containing mercaptobenzothiazol and ethanolamine group (BMB) was synthesised and characterised. Its tribological properties in RSO were evaluated using a four‐ball tribometer, and its action mechanisms were investigated by scanning electron microscopy and X‐ray photoelectron spectroscopy. Its hydrolysis stability was investigated by open observation method and half‐time method, and its mechanism was discussed through Gaussian calculation. Results show that BMB possesses excellent extreme pressure, better anti‐wear performances and excellent hydrolysis stability for lone electron of nitrogen atoms forming a coordination effect with B atom. The boundary film, which contains organic nitrogen and inorganic salt, such as BN, Fe₂(SO₄)₃ and Fe‐O‐B, contributed to improve the tribological properties of RSO. Copyright © 2013 John Wiley & Sons, Ltd.     

水溶性复合磷酸酯添加剂抗磨性能研究

合成了水溶性复合磷酸酯,利用四球试验机考察了添加到水溶液中的抗磨性能,并优化了复合磷酸酯的配比,用扫描电子显微镜对钢球磨斑形貌和摩擦表面的元素组成进行了分析,四球结果表明,磷酸酯与硫化物硫脲,油性剂油酸三乙醇胺具有良好的协同抗磨效应,并存在一个最佳配比,电镜能谱分析表明,复合磷酸酯水溶液在摩擦表面与Ｆｅ发生化学反应,生成一种含磷富硫的化学反应膜,而且表面膜中硫,磷元素的含量比为２：１时极压抗磨性能     

Tribological studies on a novel borate ester containing benzothiazol-2-yl and disulfide groups as multifunctional additive

A novel borate ester derivative containing benzothiazol-2-yl and disulfide group (BTSB) was synthesized and characterized. Its tribological properties used as EP and multifunctional additive in rapeseed oil were evaluated using a four-ball tribometer, and its action mechanisms were investigated by the X-ray photoelectron spectroscopy. Results show that the BTSB possesses comprehensive tribological properties in load-carrying, friction-reducing, antiwear, corrosion-inhibiting, and anti-oxidation, which probably has a chance to replace ZDDP partially. Moreover, the decomposed borate esters, organic sulfide and nitrogen adsorbed on worn surface were detected, and S element in BTSB reacted with metal and generated FeSO₄, both of which contributed to the formation of boundary lubricating film.     

A tribological study of (2‐sulphurone‐benzothiazole)‐3‐methyl‐dibutyl borate

An organic compound containing S, N, B, and O was synthesised by reacting 2‐mercaptobenzothiazole and formalin in ethanol solution, the resulting product then being reacted with butanol and boric acid in toluene solution. The tribological performance of the novel compound when added to liquid paraffin was evaluated using a four‐ball tester and a ring‐on‐block machine. The relationship between performance and concentration was analysed, and the results show that the compound possesses good antiwear and load‐carrying abilities. The mechanism of action of the additive was investigated using X‐ray photo‐electron spectroscopy (XPS). Surface analysis indicated the formation of a protective film containing FeSO₄, an organo‐sulphur compound, FeS₂, borate, and an organonitrogen compound. This protective film formed during sliding processes contributes to the increase in wear resistance.     

Tribological behavior and lubricating mechanism of Cu nanoparticles in oil

Nanosized Cu, modified by an organic compound containing S and P was synthesized using a surface‐modification method. The size and structure of the Cu nanoparticles were characterized by means of a transmission electron microscope (TEM) and electron diffraction (ED). Their tribological behavior was evaluated on a four‐ball machine. The results showed that Cu nanoparticles as an oil additive have better friction‐reduction and antiwear properties than ZDDP, especially at high applied load. Meanwhile, they can also strikingly improve the load‐carrying capacity of the base oil. The rubbed surface was investigated by electron probe microanalysis (EPMA) and X‐ray photoelectron spectroscopy (XPS). It was found that the boundary film on the worn surface consisted of a Cu nanoparticle deposited film and a tribochemical reaction film containing S and P. A synergistic effect between the deposited film and tribochemical reaction film contributes to the good tribological properties of oil. This revised version was published online in July 2006 with corrections to the Cover Date.     

Room temperature ionic liquid 1-ethyl-3-hexylimidazolium-bis(trifluoromethylsulfonyl)-imide as lubricant for steel–steel contact

The ionic liquid 1-ethyl-3-hexylimidazolium-bis(trifluoromethylsulfonyl)-imide was synthesized and evaluated as lubricant for the contact of steel/steel. The tribological properties of the ionic liquid as lubricant were investigated on an Optimol SRV oscillating friction and wear tester in ambient condition. The synthetic ionic liquid shows excellent tribological performance and is superior to the ionic liquid of alkylimidazolium tetrafluoroborate and the conventional high temperature lubricants X-1P and PFPE in terms of antiwear performance and load-carrying capacity. The elemental composition and chemical nature of the boundary film generated on the steel surface were analyzed on a scanning electron microscope with a Kevex energy dispersive X-ray analyzer attachment (SEM/EDS) and X-ray photoelectron spectrometer (XPS), and the XPS results indicate the occurrence of a complicated tribochemical reaction of ionic liquid with iron on the rubbing surface during the sliding process, with the formation of FeS, organic fluoride, inorganic fluoride, etc.     

新型含氮、硫杂环有机硼酸酯在菜籽油中的摩擦学性能研究

从分子设计的观点出发,合成了一种新型含氮、硫杂环有机硼酸酯润滑油添加剂2-硫酮苯并噻唑啉-3-甲基二异辛基硼酸酯（ITTB）。采用四球摩擦磨损试验机评价了其摩擦学性能。结果表明：在菜籽油（RO）中加入添加剂以后,其承载能力明显提高,磨斑直径和摩擦因数均显著降低。从磨斑表面SEM,XPS分析结果可以推断,添加剂在摩擦过程中发生了摩擦化学降解反应,硫元素在钢球的表面形成了一层含Fe2（SO4）3和FeS2的反应膜,氮、硼元素则以吸附膜的形式存在于摩擦表面,2种膜的共同作用提高了菜籽油的减摩抗磨性能及承载能力。     

Lubricating Properties of Organic Phosphate Ester Aqueous Solutions

The lubricating properties of organic phosphate ester (DPZ) aqueous solution were investigated using the tribological testers and the home-built thin film interferometry. Experimental results indicate that DPZ can adsorb on the surfaces of rubbing pair, reduce the friction coefficient of boundary lubrication, and significantly improve the anti-seizure properties of water. Under the elastohydrodynamic lubrication (EHL), the lubricating film thickness decreases with the DPZ concentration increasing. It is thought that a preferential slip plane, which is created against the adjacent layer between the hydration sheath around the polar headgroups of DPZ molecules and bulk water, dramatically weakens the water film by breaking the H-bond network around surface.