The performance and antiwear mechanism of S-containing organic borate as an oil additive

A sulphur-containing organic borate (BS-2) was prepared. Its friction and wear properties when added to n-tetradecane, and the effect on wear of addition of dodecyl amine to the synthesised S-containing borate oil, were measured using a Timken test machine. The results were compared with those of tridodecyl borate, and a combination of tridodecyl borate and sulphurised cotton seed oil. X-ray Photoelectron Spectroscopy (XPS) was used to examine the rubbed surfaces of the test blocks, while Scanning Electron Microscopy (SEM), Energy Dispersion Analysis of X-ray (EDAX) and X-ray Diffraction (XRD) were used to study the wear debris. It is found that S-containing organic borate exhibits a poorer antiwear property than tridodecyl borate but, with the addition of dodecyl amine to the S-containing borate, its antiwear property can be improved. XPS analyses indicate that sulphur on the rubbed surfaces exists in the forms of organic sulphide and FeSO₄, and the addition of amine reduces the adsorption and reaction of sulphur to the rubbing surfaces. SEM analyses revealed that the wear debris was in powder form, and the EDAX and XRD analyses indicated that iron sulphide, iron oxide and elemental iron were contained in the wear debris. A corrosive wear mechanism of steel test blocks lubricated by S-containing organic borate is proposed.     

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。     

Study of the tribological performance of a rare earth naphthenate as a lubricant additive

The tribological behaviour of a rare earth naphthenate (REN) as a lubricant oil additive in VG26 white oil and the complexes of REN and organo‐sulphur or organo‐phosphate compounds have been evaluated with a four‐ball friction and wear tester. The chemical features and elemental composition of the boundary lubricating film were examined by means of Auger electron spectroscopy (AES) and X‐ray photoelectron spectrometry (XPS). The results show that REN exhibits good antiwear, load‐carrying, and friction‐reducing properties in the base stock. When 2.0% REN is added, the wear‐scar diameter value reduces to 54.7% of that for the base stock alone and the maximum non‐seizure load increases 2.95 times. A synergistic effect is found for the load‐carrying capability of the complex of REN and organo‐sulphur while poor compatibility is exhibited for the complex of REN and organo‐phosphate. The analytical results of AES and XPS indicate that the good performance of REN is attributable to the formation of a boundary lubricating film mainly composed of naphthenic acid, rare earth oxide, and complexes of rare earth metals, which is formed on a rubbed surface when lubricated by oil containing the REN additive.     

Effects of Using Alternative Extreme Pressure (EP) and Anti-Wear (AW) Additives with Oxy-Nitrided Samples

Oxy-nitriding is a widely used industrial process aiming to improve the tribological properties and performance of components. Previous studies have shown the effectiveness of the treatment with friction and wear performance, but very few have focussed on optimising this behaviour. The lubrication properties of several EP and AW additives were examined to investigate their effectiveness in improving the tribological properties of the layers formed after treatment. Previous studies showed the presence of an oxide layer on the sample could improve the effectiveness of the sulphurised olefin (SO) and tricresyl phosphate (TCP) additives. The friction and wear behaviour of oxy-nitrided samples were analysed using a tribometer and surface profiler. Scanning electron microscope, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy were employed to identify the morphologies and chemical compositions of the treated surface before and after testing. No real effect on friction was observed when using the SO or TCP additives, mostly due to lack of interaction with the less reactive iron nitride layer and their roles as anti-wear additives. However, when the zinc dialkyldithiophosphate-containing lubricant was used, a higher friction coefficient was observed. Greater improvements in anti-wear properties with the presence of additives in comparison with only using base oil were reported, with the TCP additive producing the lowest wear rates. The study effectively demonstrated that the additive package type used could impact the tribological and tribochemical properties of oxy-nitrided surfaces.     

Friction and wear behaviors of aluminum-on-steel under the lubrication of grease containing a complex of lanthanum dialkyldithiocarbamate and phenanthroline

A complex of lanthanum dialkyldithiocarbamate and phenanthroline was synthesized, and its lubricating and antiwear behaviors as an additive in lithium grease were evaluated using a Timken tester with a SAE52100 steel ring sliding under an A1 2024 block. As a comparison, the wear behavior of a steel-on-steel system under the lubrication of the same grease was also investigated under the same test conditions. The protective film formed on the rubbed surface of aluminum was investigated by both XPS and AES. Results of friction and wear tests indicate that this rare earth complex possess good antiwear ability for aluminum, and its antiwear and friction reduction properties for the aluminum-on-steel system is even superior to that for the steel-on-steel system. The results of AES and XPS analyses illustrate that the prepared La complex as an additive in lithium grease forms a protective film containing lanthanum oxide, aluminum sulphide, and an organic compound containing sulfur and nitrogen on the rubbed surface of aluminum.     

The synergistic effects of EP and AW additives with a sulphurised steel surface under boundary lubrication

In this paper the synergistic effect on tribological behaviour of two additives, sulphurised olefin and tricresyl phosphate, in paraffin oil, and 1045 steel, treated by sulphurisation, was studied on a ball-on-disc test machine. An excellent load-bearing capacity was obtained by the combination of sulphurisation and the lubricant paraffin+sulphurised olefin. The mechanism of this synergistic effect is discussed, based on micro-analysis of the surface film by AES and XPS.     

Soluble molybdenum compound and sulphur ep additive combinations: Synergistic and adverse effects on antifriction and antiwear characteristics

Antifriction and antiwear performance of three soluble molybdenum (Mo) compounds (Mo dithiophosphate, Mo dithiocarbamate and Mo amine complex) and four sulphur-containing EP additives (sulphurised isobutylene, dibenzyl disulphide, sulphurised fat and synthesised ethylene sulphur derivative) have been studied, alone and in combination, using an SRV test rig. The additive behaviour in combination has been found to be selective, and dependent on the chemistry and ratio of the additive components. Certain sulphur EP additives in combination with Mo compounds have exhibited a synergistic effect. The antifriction performance of additives, in general, has been found to be further enhanced at higher test temperatures. However, a reduction in antiwear property has been noticed.     

The application of photoelectron spectroscopy to the study of e. p. films on lubricated surfaces

Photoelectron spectroscopy (ESCA) has been used to examine films formed on the surfaces of steel specimens by oil solutions of e.p. additives in immersion and rubbing tests. The additives used were elemental sulphur, dibenzyl disulphide, a commercial zinc dialkyldithiophosphate and pure zinc di-n-butyldithiophosphate. In the case of the two sulphur additives immersion specimens had films containing sulphate and free sulphur, whereas rubbed surfaces had patchy coatings of sulphide with lesser amounts of sulphate. The thiophosphate additives gave broadly similar films in rubbing and immersion tests. These contained the zinc, phosphorus and part of the sulphur in the original additive in films, possibly polymeric, of somewhat variable composition. Argon ion etching was used to explore the composition of a film from a thiophosphate additive. It showed that there were no large compositional variations through the thickness of the film and that it was of a discontinuous patchy nature.     

A study of S-[2-(acetamido) benzothiazol-1-yl]N,N-dibutyl dithiocarbamate as an oil additive in liquid paraffin

A heterocyclic derivative of S-[2-(acetamido) benzothiazol-1-yl]N,N-dibutyl dithiocarbamate was synthesized and its tribological behavior as an additive in liquid paraffin was evaluated using a four-ball tester. The nature of the film formed on the rubbed surface was investigated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). On the basis of the experimental results, the novel additive shows excellent antiwear property and friction reduction property similar to ZDDP, and exhibits better load-carrying capacity than ZDDP. Besides those, the novel compound has good anticorrosive property and high thermal stability. The results of XPS analyses illustrate that the prepared compound as an additive in paraffinic base oil forms a protective film containing ferric sulfide, ferric sulfate, organicsulfur compound and organicnitrogen compound on the rubbed surface.     

Additives for Rape Seed Oil 1: Preparation and Tribological Behaviour of a Sulphurised Rape Seed Oil Lubricant Additive

A new type of environmentally friendly lubricant additive ‐ a sulphurised rape seed oil additive ‐ was prepared, and the chemical structure characterised using infrared spectroscopy. The tribological properties of the additive in a rape seed base oil were evaluated using a friction tester. The morphologies and tribochemical species of worn surfaces were analysed by means of X‐ray photoelectron spectroscopy. The results show that the additive increased the load‐carrying capacity and improved the antiwear and friction‐reducing properties of the rape seed oil. The inferred lubrication mechanism is that a high‐strength adsorption film and a tribochemical reaction film form on rubbing surfaces due to the carrier effect of the long‐chain rape seed oil molecules, the high reactivity of sulphur, and their synergism.     

Friction and wear behaviour of an Al-Si alloy against steel lubricated with N- and O-containing organic compounds

The friction and wear properties of an Al-Si alloy against AISI 52100 steel were investigated with a block-on-ring wear tester lubricated with a liquid paraffin base oil containing organic additive compounds, such as ethylenediamine, ethyleneglycol, ethanolamine, and N,N-dibutylethanolamine. The boundary film formed on the rubbed surface of the Al-Si alloy was then examined using FT-IR microscopy and XPS. The friction and wear tests revealed that ethylenediamine, ethanolamine and N,N-dibutylethanolamine additives provide good lubrication in the Al-Si alloy-on-steel system, especially N,N-dibutylethanolamine. FT-IR microscopy and XPS revealed the possible formation of a chemically stable five-ring complex of aluminium or silicon with diamine and ethanolamine.     

点/线/面接触条件下喹唑啉酮胺润滑油添加剂的摩擦学性能

目前杂环化合物作为润滑油添加剂在机械润滑领域受到重视,但对无硫磷含氮杂环化合物在多种接触方式下的摩擦学性能的研究还不多。合成一种新型无硫磷喹唑啉酮胺润滑油添加剂并利用四球试验机、环块试验机和万能摩擦磨损试验机分别考察了点/线/面接触条件下其在液体石蜡中的摩擦学性能,再用光学显微镜、扫描电子显微镜和X射线光电子能谱仪对其摩擦表面进行分析。试验结果表明:油溶性喹唑啉酮胺在液体石蜡中能显著改善基础油的摩擦磨损状况,明显提高基础油的承载能力,表现出良好的摩擦学性能,其作用机理是其在摩擦过程中与金属表面发生了摩擦化学反应,生成了含氧化亚铁、有机氮化物和含氮金属配合物等的复合膜,有效地提高了液体石蜡的减摩抗磨性能。     

The performance and antiwear mechanism of (2-sulfurone-benzothiazole)-3-methyl esters as additives in synthetic lubricant

The load-carrying capacity, friction and wear properties of three (2-sulfurone-benzothiazole)-3-methyl esters added to a synthetic lubricant (triester) were evaluated using a four-ball tester and a ring-on-block machine. The results indicate that these compounds added to the triester possess good load-carrying capacities and antiwear properties. The rubbed surface was investigated by X-ray photoelectron spectroscopy (XPS). The analysis indicates that a lubricating film is formed on the metal surface by adsorption and chemical reaction.     

水溶性含氮硼酸酯摩擦学性能研究

利用四球机和环块试验机考察了两种水溶性含氮硼酸酯的摩擦学性能,并用X－射线光电子能谱仪（XPS）对摩擦表面进行了分析,摩擦学试验表明：含氮硼酸酯在水中具有良好的减摩抗磨性能和承载能力,表面分析证实含氮硼酸酯在摩擦过程中发生了摩擦化学反应,生成了含硼酸,三氧化二硼,有机氮等的复合膜,有效地提高了水基液的抗磨减摩性能和承载能力。     

二聚酸盐的合成及在水性基础液中的摩擦学及防腐防锈性能

采用二聚脂肪酸和二乙醇胺合成一种二聚酸二乙醇胺盐,在四球摩擦磨损试验机上考察其在水性基础液中的摩擦学性能,用 X 射线光电子能谱仪（XPS）分析试验后钢球磨斑表面典型元素的化学状态。结果表明：该添加剂在水性基础液中具有优良的承载能力和抗磨减摩性能以及良好的液相防锈和抑制铜片腐蚀的性能;在摩擦过程中,磨斑表面形成了含氮的吸附膜和含 Fe2 O3的化学反应膜,二者协同作用使添加剂在摩擦过程中具有良好的抗磨减摩性能。     

Additive—additive interaction: A study of the ep and AW performance of sulphurised jojoba oil and sulphurised xanthate in the presence of mocontaining friction modifiers

The extreme-pressure (EP) and antiwear (AW) performance of three soluble molybdenum compounds (commercial molybdenum dialkyldithiophosphate, commercial molybdenum dialkyl dithiocarbamate, and synthesised molybdenum dialkyl dithiocarbamate), and two sulphur-containing EP compounds (sulphurised jojoba oil and sulphurised O-stearyl-S-oleyl xanthate) have been studied alone and in combination, using a four-ball tester. The behaviour of the additives in combination has been found to be selective, and dependent on the chemistry and ratio of the additive components. In general, the addition of Mo-type friction modifiers (FM) to sulphurised EP compounds has shown a synergism, of varying order, in their EP and AW properties.     

Effect of chemical structure of borates on the tribological characteristics of magnesium alloy during sliding

Effects of four borates with different chemical structure on the tribological properties of magnesium alloy in sliding contact with bearing steel were investigated under boundary lubrication using a Timken type tester. It was shown that the borate without active element is not effective at reducing the friction and wear of magnesium alloy, and the borates containing nitrogen, sulfur and chlorine are effective at improving the tribological properties of magnesium alloy. Different active elements have different action characteristics at improving the tribological properties of magnesium alloy. The rubbed surfaces were investigated using Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS), the wear mechanisms were also proposed.     

含硫氮硼酸酯在菜子油中的摩擦学性能研究

合成了一种新型含硫氮硼酸酯润滑油添加剂，利用四球摩擦磨损试验机考察了其在菜子油中的摩擦学性能，并用x射线光电子能谱仪分析了磨斑表面的元素化学状态。结果表明：含硫氮硼酸酯可显著改善菜子油的减摩抗磨性能和承载能力；含上述添加剂的菜子油在摩擦过程中发生了摩擦化学反应，生成了含菜子油甘油酯、有机硫化物、硫酸亚铁、三氧化二硼等组成的边界润滑膜，从而改善了菜子油的摩擦学性能。     

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。     

The Preparation and Tribological Investigation of Ni–P Amorphous Alloy Nanoparticles

Amorphous Ni–P alloy nanoparticles were synthesized by chemical reduction of nickel acetate in water reacted with sodium hypophosphite under stirring. The nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Results of XRD and TEM showed that nanoparticles have an average diameter 100 nm. And XPS analysis indicated that part of the surface of Ni–P amorphous alloy nanoparticles was oxidized. The tribological properties of the prepared Ni–P nanoparticles as an additive in lithium grease were evaluated with a four-ball friction and wear tester. The worn surfaces of the lubricated GCr15 steel were analyzed by means of XPS and scanning electron microscopy (SEM). The lubricating mechanisms were discussed on the basis of XPS and SEM analyses of the worn steel surfaces. The results show that these nanoparticles as a grease additive can effectively enhance the friction-reduction and antiwear ability of lithium grease. Tribochemical reactions were involved for steel–steel frictional pair lubricated with the lithium grease containing amorphous Ni–P alloy nanoparticles, with the formation of a boundary lubricating and protecting film composed of additives of lithium grease and tribochemical reaction products (iron phosphate, iron oxides, nickel oxide, nickel, etc.) of the lubricants. This contributes to improve the tribological properties of the lithium grease.