Lubricant Composition Research Articles

Study of Influence of Metal-sealing Additive on Operating Characteristics of Machine Power Plants

. The article considers the issues of creating a lubricating composition which is an internal complex salt and possesses anticorrosive properties along with thermal oxidative stability. Antifriction and anti-wear properties of the additive were investigated, the wear of parts in friction units was reduced by 3.2-7.5 times within the normal force range of 73.15-115.15 kgf.

Interlayer graphene oxide/binary ionic liquids composite lubricating films with improved load-carrying and anti-wear properties

A composite lubricating film with interlayer graphene oxide (GO) and binary ionic liquids (ILs) is prepared on a silicon (Si) surface. The tribological performance of the composite lubricating film is significantly increased compared with that of Si surface and GO films. Specifically, compared with the Si surface, the adhesion and friction forces of composite lubricating film at nanoscale are reduced by about 65% and 60%, respectively. Furthermore, in the microscale, the friction coefficient is reduced by 43% of GO films. The antiwear lifetime is markedly prolonged to 41 mins under an applied load of 400 mN, which is over 22 times longer than that of GO films. It is expected that the interlayer GO/binary ILs composite lubricating films are widely applied in nano/micro-electro mechanical systems, due to the low adhesion, excellent load-carrying performance, and anti-wear property at both nano and micro scales.

In-situ intercalated pyrolytic graphene/serpentine hybrid as an efficient lubricant additive in paraffin oil

In this study, a novel lubricant additive hybridizing pyrolytic graphene and serpentine was reported for the first time to enhance the tribological performance of paraffin oil. The in situ produced pyrolytic graphene from pyrolysis of citric acid was observed to be intercalated into the interlayer of serpentine sheets. The structure, morphology and chemical composition of the composite lubricant additives were characterized by scanning electron microscope, X-ray diffractometer and Fourier transform infrared spectroscopy. In addition, the anti-wear and friction-reduction mechanisms of the hybrid lubricant additive, owing to its activity on the friction interface, were disclosed by exploring the morphology and component of the wear scar after friction. The tribological results revealed that introducing a small amount of pyrolytic graphene/serpentine lubricant additive (0.2 wt%) to the base oil could effectively reduce the friction coefficient (~87%) and wear loss (~71%) in comparison with neat paraffin oil. First-principles calculations based on density functional theory were further performed to uncover the lubrication mechanism of the hybrid. Therefore, the pyrolytic graphene/serpentine hybrid reported herein represents a new strategy to prepare high efficient lubricant additive.

Influence of the Tool’s Surface Microgeometry and the Lubricant Composition on Hole Precision in Hybrid Burnishing

Influence of the Tool’s Surface Microgeometry and the Lubricant Composition on Hole Precision in Hybrid Burnishing

Tribological behavior of PTFE/Nomex/phenolic composite lubricant under cold forming condition in the bearing assembly process

Tribological behavior of PTFE/Nomex/phenolic composite lubricant under cold forming condition in the bearing assembly process

ANTI-CORROSION PROTECTION OF MILITARY EQUIPMENT

Corrosion of metals is a key problem for military equipment, weapons and ammunition. Its pernicious impact leads to losses of both the metal itself and the fact that corrosion wear of parts of mechanisms, assemblies reduce the accuracy and reliability of their action, as a result, and the readiness of the equipment. Therefore, protection against corrosive destruction of military equipment, weapons and ammunition is an urgent aim of today.
 To prevent corrosion processes, a rational method of protection is the use of inhibitors, which, at low capital costs, prevent the destruction of equipment, structures and mechanisms. Therefore, inhibitors are added to some lubricating oils that have long-term contact with metals and alloys, and wear of parts as a result, corrosion is reduced. Such lubricants can be used as corrosion protection by applying them on a metal surface. Inhibitors based on mustard oil are designed to protect the surfaces of steel equipment and communications operated in acidic and neutral working environments and have a high protective effect – 95-99.5%.
 The article considers the issues of anticorrosion protection increase of steel surfaces by introducing an effective environmentally-safe corrosion inhibitor into the composition of anti-friction lubricant used in the operation and storage of military equipment, weapons and ammunition. The introduction of the inhibitor increases the anti- corrosion properties of the lubricant by forming a protective adsorption film on the steel surface that prevents the corrosion activators from accessing the metal, which is confirmed by the results of the electronic spectrometry.

Impact of Ag on the microstructure and tribological behaviors of adaptive ZrMoN–Ag composite lubricating films

Solid lubricating films have great advantages in extreme operating conditions. In this research, silver (Ag) was doped into the ZrMoN composite film to develop a composite polyphase structure with enhanced mechanical and tribological properties. A series of ZrMoN–Ag composite films with different Ag content were prepared. The results show that the composition phases of the composite films are fcc-Mo2N、fcc-ZrN, and nano-crystalline fcc-Ag was dispersed in the films. The ZrMoN–Ag composite films exhibited excellent mechanical properties with a hardness of 27.6 GPa and elastic modulus of 286.8 GPa. In addition, the ZrMoN–Ag composite film with Ag content of 11.88 at.% possessed the advantage of low friction coefficient in a wide temperature range, attributing mainly to the synergetic effect of Ag phase and friction oxidation products. This work provides a promising solution for designing solid self-lubrication composite in wide temperature domain.

Influence of microgeometry of tool working surfaces and lubricant composition on the accuracy of dimensions and shapes of holes in combined burnishing

The influence of the microgeometry of the working surfaces of the tool and the composition of the lubricant, implementing the wear-free effect of Garkunov — Kragelskiy in the combined burnishing of holes in workpieces from the non-grinding alloy LS 59-1, on their accuracy is studied. Keywords; combined burnishing, hole, regular microrelief, wear-free effect, friction, accuracy. nadezhdachi@yandex.ru, bekaev@list.ru, ld-gim@yandex.ru

Excellent effect of lubrication performance of chitosan/polyethylene glycol/palygorskite as water‐based lubricating additive on 304 stainless steel and polymer pairs

AbstractIn this work, Palygorskite (Pal) nanorods, chitosan (CS), and polyethylene glycol (PEG) are used to prepare new composite lubricants in order to improve the lubrication performance of water. The tribological experimental results showed that the composite lubricant composed with 1 wt% Pal, 10 wt% PEG and 2 wt% CS has excellent lubrication performance. The tribological data showed that the friction coefficient reached 0.021, and the composite lubricant lubrication performance was about 4 times higher than that of deionized water. The materials were characterized by scanning electron microscope (SEM), thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy (XPS), which revealed that the composite lubricant contained many oxygen‐containing functional groups, and there was no chemical reaction between these functional groups. Instead, a lubricating film that can reduce friction and wear was formed through the hydrogen bond effect between functional groups. In this paper, a general and simple preparation method of new composite lubricant was proposed, which can be wildly used in many fields such as water‐based lubrication.

Development of biostable lubricant composition of М-12ВБ motor oil for marine diesel engines

The paper is dedicated to the development of biostable lubricant composition of М-12ВБ motor oil on domestic raw, foreign additives, additive packages, as well as multi-function additives of AKI series obtained as a result of condensation of calcium salts with alkylphenol, formaldehyde with vari-ous amines. During development of up-to-date lubrication compositions the additives of polymethacry-late of Viscoplex-8-450; -4-550; 2-670; 1-810 seies of German Evonik have been used and the results of studies their mechanical and chemical destruction presented. For the specification of biological stability of new lubrication compositions a-aril-b-nitroeten, a-furil-b-nitroeten and their hallogen derivatives have been used. It was defined that adding biocides do not negatively effect the changes of antioxidizing, anticorrosion, antiwear, lubricating and other significant operation properties and characteristics of the oils. Biostable composition of M-12BБ motor oil for marine and stationary diesels meeting all GOST requirements has been developed.

Preparation and Study on Fretting Tribological Behavior of Composite Lubrication Structure on the Titanium Alloy Surface

As an excellent light metal material, titanium alloy has an important application in high technology equipment. In this study, the composite lubrication structure was prepared on the titanium alloy surface by combining the surface texture, thermal oxidation layer, and polytetrafluoroethylene (PTFE)-based lubricating coating. The effect of texture parameters and thermal oxidation layer on the fretting wear behavior of the composite lubrication structure was evaluated under a load of 50 N. The results showed that the PTFE-based lubricating coating on the textured surface showed excellent friction-reduction and anti-wear effect compared with the coating on the single smooth surface and thermal oxidation surface. The introduction of a thermal oxidation layer on the textured surface further improved the fretting wear life of lubrication coating. The friction coefficient and wear rate can be as low as 0.242 and 2.3 × 10−5 mm3·N−1m−1, respectively, under dry fretting contact conditions. Compared with the untextured surface, the longevity of the composite lubrication structure is extended by more than 90%.

Экспериментальное исследование трибологических характеристик смазочных масел со слоистыми модификаторами трения и возможности их применения в судовой технике

The paper presents the results of studying the lubricity of several lubricating compositions, two of which contain an antiwear additive based on a layered friction modifier - molybdenum diselenide. Oil MC-20, which does not contain functional antiwear additives, is used as a base lubricating medium and an object of comparison. Two variants for combining an antiwear additive with this oil differ in the process of initial preparation of the additive before adding it to the base lubricating oil by rotary pulsation grinding and stirring. Antiwear tests are arranged in the form of a consistent tribological rating of the given types of lubricating media at various operating time of the friction path of the test samples. The test tool is a rotary-type friction machine of an original design. There are analyzed the differences in the antiwear test methodology and the advantages of the proposed scheme over the analogous one, which is relevant for GOST R 51860-2002. Among the results of the tribological study carried out, topographic patterns of wear of test specimens, the dependence of the wear rate of tribological surfaces on contact pressures, and the dependence of the wear scar diameter on the amount of specimen wear are given. The antiwear additive has been found to contain a layered friction modifier of selenium dichalcogenide (molybdenum diselenide) type, it improves the lubricating film on friction surfaces and reduces their wear compared to the use of nonadditive oil MS-20. The wear degree of a stationary ball-shaped specimen when testing a lubricating medium with the antiwear additive is reduced by 66-85% compared to a base lubricating oil without additives. The diameter of the wear spot on a stationary specimen under these test conditions is reduced by 28-67%, which proves the effectiveness of preliminary preparation by rotary-pulsation mixing of a lubricant composition with a solid suspended base even with a relatively short preparation time.

The effect of top of rail lubricant composition on adhesion and rheological behaviour

The effect of top of rail lubricant composition on adhesion has been investigated using a laboratory ball-on-disc tribometer. Rheological properties were analysed using viscosimeter and high pressure torsion device. As a base medium, a biodegradable ester oil with bentonite thickener was selected. Added particles for friction modification were aluminium oxide, zinc oxide, copper sulfide and solid lubricants molybdenum disulfide and graphite. The effect of these components in the base medium on adhesion was evaluated. It was found that the most dominant component was the solid particles for friction modification. Based on the results, top of rail lubricant substances were prepared and tested. The best performing substances provided the optimal level of adhesion. These substances also showed resilience to overdosing, which caused commercial products to provide very low adhesion conditions. The rheological investigation confirmed the very low adhesion is controlled by elastohydrodynamic regime while the stable values are a result of transition to boundary lubrication.

Regulation on tribological performance of tungsten-doped DLC coatings by choline chloride-urea and-thiourea deep eutectic solvents

Solid-liquid composite lubrication system has attracted an increased interest for low friction and wear. Nevertheless, the effect of mechanical and surface properties of the solid materials, especially the mechanical and surface properties governed by doping elements, on the tribological performance solid-liquid composite lubrication system is still not well comprehended. Here, we reported the effect of W content on the mechanical and surface properties of W-DLC coatings as well as the tribological properties of W-DLC coatings under (choline chloride-urea and choline chloride-thiourea) deep eutectic solvents lubrication. Although the wear of W-DLC coatings under dry friction increases with W content, the wear under DESs is slight when coatings show excellent wettability to DESs or a DES-derived tribochemical film is formed. We demonstrate that the tribological behavior of W-DLC and DESs composite lubrication system is related to the mechanical properties of W-DLC coatings together with the contact angle and tribochemical interaction between DESs and W-DLC coatings.

Research the effect of additives on tribological characteristics of lubricant material and morphology of friction surfaces

At present, special attention is paid to the issues of increasing the wear resistance of the surface layers of the material of rubbing parts and reducing the energy consumption for friction. It is possible to form surface films with high tribological properties by introducing various metal-containing additives into the base oil, which, depending on the design and technological features of the friction pair and operating conditions, can differ significantly. In order to study the mechanism of action of various additives to oils from the point of view of the formation of surface layers with effective operational properties, the tribological properties of experimental lubricating compositions were determined and the morphology of the friction surfaces of machine parts was investigated. For comparative tests, the following additives were chosen as samples - MOTOR DOKTOR (MANNOL) and the metal-cladding additive Cluster. As a result of laboratory tribological tests of friction samples on pure MS-20 oil and containing tribological preparations MANNOL (MOTOR DOKTOR) and Cluster, it was found out that the use of the Cluster nanoadditive led to a decrease in the friction moment by 80% in comparison with the additive MANNOL (MOTOR DOKTOR) and 1.48 times compared to MS-20 oil. During the test, the wear of the pad of the model friction pair operating on MS-20 oil with the Cluster additive decreased by 3 times compared to the wear on MS-20 oil with the MANNOL additive (MOTOR DOKTOR) and 26 times compared to the base oil MS-20. On the working areas of the friction surfaces of the model samples after their operation on MS-20 oil with MANNOL (MOTOR DOKTOR) and Cluster additives, the formation of films of various nature and secondary structures is observed, which are manifested by a specific relief structure. Such a change in the surfaces of the working sections is associated with the peculiarities of the influence of various compositions of additives in the oil not only on the processes of friction and wear, but also on structural and phase changes in the surface layers of metals in friction samples.

Effects of Curved Microchannel Surfaces with Sn-Ag-Cu and MXene-Ti3C2 on Tribological Performance of M50 Bearing Steel in Solid–Liquid Composite Lubrication System

Effects of Curved Microchannel Surfaces with Sn-Ag-Cu and MXene-Ti3C2 on Tribological Performance of M50 Bearing Steel in Solid–Liquid Composite Lubrication System

Parametric analysis of residual deformations in innovative mandrelling methods of holes in aluminum alloy workpieces

The influence of the nature and parameters of the microgeometry of the impacting surfaces of the tool, as well as the composition of the technological lubricant on residual deformations in the methods of combined mandrel holes of duralumin D1T workpieces has been studied comparatively.

ВЛИЯНИЕ РАЗНОРОДНЫХ ТВЕРДОФАЗНЫХ ДОБАВОК В МИНЕРАЛЬНОЕ МАСЛО НА ЕГО СМАЗОЧНУЮ СПОСОБНОСТЬ

In the last two decades, there has been an increase in practical interest in ultrathin powders used as solid-phase additives in lubricants. The research results published in the domestic and foreign literature indicate an increase in the lubricity of mineral oils when introducing heterogeneous superfine powders into their composition. Getting into the gaps between the rubbing parts, particles of ultrafine powders participate in the formation of surface layers with effective tribological properties, exhibit a restorative effect (fill microcracks and pores). The addition of ultrafine powders to the base oil is a promising approach to reducing friction, wear, and, as a result, to increasing the service life of tribo-conjugations of machines. The tribological characteristics of lubricating compositions based on MS-20 mineral oil modified with ultrafine additives containing micro-ceramics and non-ferrous metal powders are studied. It was found that the introduction of the studied tribocompositions into the base oil leads to an improvement in its lubricity. It is shown that the best antifriction and anti-wear properties of the lubricant composition are provided by the metal-containing nano-additive Cluster. The use of the Cluster additive reduces the temperature of the lubricating medium by 26%, the friction moment by 40.5%, wear by 26 times compared to the base oil. When the samples were lubricated with a composition containing micro-ceramics MS-20+WINDIGO Micro Ceramic Oil, there was a slight decrease in the temperature of the lubricating medium, an increase in the moment of friction by 17%, and wear by 2.5 times, compared with MS-20+Cluster. The morphology of the friction surfaces of the samples was studied by light microscopy. Significant differences were found in the reliefs of the friction surfaces, as well as in the tribofilm formed under the influence of components of dissimilar solid-phase additives.

Application of special lubricating compositions to increase the efficiency of friction surface run-in

The paper presents the results of laboratory studies of a number of additives introduced during operation to motor oil of internal combustion engines. It also evaluates their impact on tribological characteristics of friction pairs. It was found that all studied additives have a positive effect on the running-in quality. Reduced wear of friction pairs, reduced surface roughness compared to base motor oil is determined. The best indicators were recorded with the FENOM additive. The decrease in wear was 46% and roughness – 23.5% compared to the base oil.

Особенности определения состава морозостойкой полужидкой смазки для районов с особо холодным климатом

The article deals with the development results of the frost-resistant semi-liquid lubricant composition to be used in extremely cold climate areas. These results are based on studying the chemmotology process mechanism in lab equipment that simulatesthe operating conditions which are used in engineering equipment, and on the standard influence patterns of additive agents, raised up to the level of the operating properties, and on the optimized composition and assessment of the performance potentialof the frost-resistant semi-liquid lubricant to perform its inherent properties.