Изучение реакций взаимодействия алкилксантогенатов с хлорпроизводными глицерина и исследование смазывающих свойств синтезированных соединений

Chemical reactivity, extreme-pressure (EP), and antiwear (AW) properties of binary additive systems were investigated using the hot-wire method and using four-ball test machines. Auger electron spectroscopy was also used to examine the thin wire surface and the wear scar surface for further understanding of the interactions between the EP and AW additives with iron surfaces. The results indicate that the antiwear properties of the EP and AW additives are strongly influenced by petroleum calcium sulphonate and hexadecamine salt of benzotriazole. However the extreme-pressure property is not affected by these additives. The presence of petroleum calcium sulphonate reduces the antiwear properties of these three EP and AW additives, due to its retardation of reactions of the EP and AW additives on iron surfaces. The presence of hexadecamine salt of benzotriazole improves antiwear property of the three EP and AW additives tested, most likely because it enhances their chemical reactivity. Presented at the 46th A...

Study to examine future of wear-resistant materials

The tribological performance and tribochemical analysis of novel borate esters as lubricant additives in rapeseed oil

Friction and wear characteristics of p-containing antiwear and extreme pressure additives in the sliding of steel against aluminum alloy

The synergistic effects of EP and AW additives with oxynitrided surface of steel

Extreme pressure (EP) additives are used when components are operated under extreme pressure. This work studies the effect of base oils on the tribological performance of EP additives. The difference between the adsorbability of the EP additives and that of base oils dominates the mutual compatibility and performance of the EP additive. When used, the EP additive forms a saturation layer on the rubbing surfaces. The concentration of EP additive in the saturation layer exceeds the additive concentration in the lubricants. Therefore, during operation, the protecting layer can reduce the contacting stress of rubbing surfaces by chemical and physical methods to prevent local plastic deformation from inducing serious wear. Under the harshest conditions, the immediate formation of films in a chemical reaction is important when plastic deformation of the contact region cannot be avoided. The high rate of formation of chemical films can prevent direct metal-to-metal contacts to reduce wear.

The antiwear and extreme pressure properties of some oil-water double soluble rare earth complexes part 1: their tribological behaviour in water

PurposeIn order to formulate ashless GL‐5 gear oils and high‐pressure antiwear hydraulic oils, the performances of extreme‐pressure (EP) and antiwear (AW), and the thermal and hydrolytic stability of series ashless P‐containing additives with different chemical structures are investigated by four‐ball EP test, high‐temperature oxidation test and hydrolytic stability test.Design/methodology/approach – Series ashless P‐containing EP and AW additives with different chemical structures were designed and selected, their EP and AW performances, high‐temperature oxidation, hydrolytic stability compared with the traditional zinc dialkyldithiophosphate (ZDDP) additive were investigated according to relative testing standards, and their applied performances compared with the traditional ZDDP additive were investigated using the CRC L‐37 gear oil rear axle test, Deniso T‐5D Vane Pump test and Deniso P‐46 Piston Pump test.Findings – The results indicate that two ashless neutral thiophosphate esters exhibit excellent EP and AW performances, high‐temperature oxidation and hydrolytic stability. The application performance of these P‐containing additives is also examined by CRC L‐37 rear axle test. The results show that only the oil samples with the addition of neutral thiophosphate esters correspondingly to API GL‐5 automotive gear oil can pass the CRC L‐37 gear oil rear axle test successfully. The results of further Deniso T‐5D Vane Pump and Deniso P‐46 Piston Pump tests prove that the ashless neutral thiophosphate ester is a very effective EP/AW additive for high‐pressure antiwear hydraulic oil. In one sentence, the neutral thiophosphate ester is the excellent ashless EP/AW additive and the useful substitute for ZDDP.Research limitations/implications – From the results, the neutral thiophosphate ester is the excellent ashless EP/AW additive and the useful substitute for ZDDP, however, their tribological mechanicsm and their synergic effect with the other additives used in the test base oil for the applied performance tests may be done in the future works.Practical implications – These results may be useful for the researchers to formulate some ashless high EP/AW industrial oils.Originality/value – This paper proves that the two ashless neutral thiophosphate esters exhibit excellent EP and AW performances, high‐temperature oxidation and hydrolytic stability, and is the useful substitute for ZDDP for formulating ashless GL‐5 gear oils and high‐pressure AW hydraulic oils.

The study objective is to increase the information value, accuracy and reliability of the experimental assessment results of extreme pressure and antifriction properties of the tested materials. A brief analysis of the work on the creation of test tribo-technical equipment is given. The difference between the designs of friction machines for testing using Reichert and Timken tests is shown. The design of an upgraded friction machine for determining extreme pressure, antifriction and anti-wear properties of lubricants is presented. In the proposed installation, the radial force on the friction unit ("roller - ring" or "bar – ring") is generated by a mechanism of even loading, and the assessment of extreme pressure lubricants is determined at the moment of gripping the rubbing samples, at which the motor shaft stops. As a result of upgrading the machine, it became possible to measure the friction force, the normal load and to read the friction factor, both for the lubricants under study and for friction pairs consisting of structural and instrumental materials. The results of comparative tests on the upgraded friction machine for lubricating and cooling liquids with different contents of extreme pressure, antifriction and anti-wear additives are presented. 
 A new friction machine design based on Reichert machine is developed, which allows testing structural and lubricating materials for friction and wear using both Reichert and Timken tests. At the same time, the accuracy of determining tribo-engineering characteristics of the tested materials is increased. It is found that as a result of equipping the friction machine with an even loading system and force measuring sensors, it becomes possible to determine extreme pressure and anti-friction properties of lubricants and structural materials, as well as to estimate the value of the friction factor.

The harsh environment rolling element bearings are exposed to in iron-mining industries is replicated in a laboratory scale in this work. Bearings (SKF 7204BEP) were tested both with and without magnetite oxide (Fe3O4) contamination. In order to study the interaction between contaminants and extreme pressure additives, the rolling element bearings were lubricated with two different greases: Grease without extreme pressure and grease containing sulphur-based extreme pressure additives. Further, the effect of the contamination–additive interaction on rolling bearing performance and monitoring signals (vibration and acoustic emission) was investigated. The obtained results indicate an advantage of extreme pressure additive in case of the investigated operating conditions. Furthermore, the use of extreme pressure additives decreased wear, surface roughness, vibration and acoustic emission for both test durations of 24 h and 168 h. The decrease of the acoustic emissions and the surface roughness parameter Rq in case of the tests with a duration of 168 h as high as 70% and 60%, respectively using extreme pressure additives in comparison with the plain grease was observed. The major cause for this reduction seems to be the interaction between contaminants and extreme pressure additives.

<div class="htmlview paragraph">The major targets of transmission design today are higher efficiency, higher torque capacity and reduced size. Increasingly smaller transmissions with higher torque lead to increasing operating temperatures. This trend is further intensified by the use of noise abatement devices and improved aerodynamic body styling that reduces the airflow around transmissions. The friction in the transmission is responsible for temperature increase and efficiency losses, and thus the reduction of friction is the main measure in order to improve the efficiency and to keep the operating temperature low.</div> <div class="htmlview paragraph">The lubricant influences and is subjected to all changes of operating conditions. Higher operating temperatures result in a higher consumption of friction modifiers, extreme pressure and anti wear additives, higher corrosion and oxidation rates, and a thinner oil film separating the various components. If the lubricant is not formulated to withstand these more severe conditions the transmission may be damaged. On the other hand, the torque transmission losses and, as a consequence, the operating temperature can be reduced by the right choice of base oil and additives.</div> <div class="htmlview paragraph">In vehicle application today, most OEMs start the lubricant development in an early phase of the development of a new transmission in order to get the optimum contribution of the lubricant. These OEMs see the lubricant as a construction element needed for the development of performance optimized transmissions. In order to select the most effective combination of additives and base stocks offered by the lubricant industry, the OEMs have developed screening tests with good correlation to field performance.</div> <div class="htmlview paragraph">Such tests range from a simple bearing test to OEM-specific transmission or axle tests. We have used two tests developed by VW, that correlate well with a car installed on a chassis-dynamometer and a transmission rig test, in order to identify and quantify the influences of fluid viscosity, base stock types, and VI Improver chemistry on efficiency and operating temperature.</div> <div class="htmlview paragraph">Finally, examples of improved semi- and fully synthetic formulations with significantly reduced operating temperatures and optimum efficiency are presented.</div>

Aluminum lead bronze bearing metal. (in Russian) : E. F. Merkulov. Tsvetnye metally, v. 30, June 1957. p. 67–69

Higher demands on extreme pressure lubrication performance are posed by stringent working conditions. In this study, the synergistic tribological properties of phosphate ammonium salt in combination with active sulfurized olefin (S1) and non-active sulfurized fatty acids (S2) were investigated to meet the needs under stringent working conditions. The anti-wear mechanisms were further explored using scanning electron microscopy (SEM) with EDS, X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge structure (XANES), and focused ion beam microscopy. The experimental results indicate that P-S2 demonstrates superior friction reduction and wear resistance under low loads, potentially attributable to its higher polarity, whereas P-S1 exhibits better wear resistance under high loads. P-S1 also shows superior extreme pressure performance attributed to its higher active sulfur content and stronger film-forming ability, evidenced by a thicker friction film (82.62 nm vs. 24.28 nm for P-S2). The study highlights that the variations in the synergistic tribological performance of phosphorus- and sulfur-based additives may link to differences in molecular structure, active sulfur content, polarity, and corrosiveness, with P-S1 demonstrating enhanced extreme pressure performance possibly through the formation of a multi-layered friction film of polyphosphate, sulfide, oligophosphate, and sulfate layers.

To enhance the lubricating and extreme pressure (EP) performance of base oils, two types of oil-soluble ionic liquids (ILs) with similar anion albeit dissimilar cations were synthesized. The physical properties of the prepared ILs were measured. The anticorrosion properties of ILs were assessed by conducting corrosion tests on steel discs and copper strips, which revealed the remarkable anticorrosion properties of the ILs in comparison with those of the commercial additive zinc dialkyldithiophosphate (ZDDP). The tribological properties of the two ILs as additives for poly-α-olefin-10 (PAO10) with various mass concentrations were investigated. The tribological test results indicate that these ILs as additives are capable of reducing friction and wear of sliding contacts remarkably as well as enhance the EP performance of blank PAO10. Under similar test conditions, these IL additives exhibit higher lubricating and anti-wear (AW) performances than those of ZDDP based additive package in PAO10. Subsequently, X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometer (EDS) were conducted to study the lubricating mechanism of the two ILs. The results indicate that the formation of tribochemical film plays the most crucial role in enhancing the lubricating and AW behavior of the mixture lubricants.

DLC coating of boundary lubricated components—advantages of coating one of the contact surfaces rather than both or none