Friction Machine Research Articles

Determination of tribotechnical properties of composite samples during friction on 40Kh steel

The paper presents the results of tribotechnical tests of samples of ornamental textolite (OT), ornamental structural textolite (OST) and oxafen. The influence of the surface roughness of a 40Kh steel counter-tile on the coefficients of friction from sliding speed, friction moments from pressure and jamming load from sliding speed is considered. The tests were performed on a friction machine with a vertical axis of rotation of the spindle according to the “plane-ring” scheme when the friction pair was lubricated with MGE-10A hydraulic oil. The test loads and sliding speeds were changed stepwise. It has been found that with a decrease in the surface roughness of steel counter-tiles, the friction coefficients decrease when friction occurs on polymer composite materials. OST samples had the best indicators for reducing the coefficient of friction from the sliding speed and the moment of friction from pressure, followed by OT and oxafen samples. The bully resistance of OT samples is higher than that of OST and oxafene samples. Oxsofen samples had the highest resistance to abrasive wear by loose grain, followed by OST and OT samples.

Analysis of micromechanical and tribotechnical properties of fluoropolymers during friction on 40Kh steel

The paper presents the results of micromechanical and tribotechnical tests of samples of polytetrafluoroethylene, radiation-modified (PTFE – RM according to modes A and B), coked in comparison with the PTFE standard (Fluoroplast -F4). The influence of the surface roughness of a 40Kh steel counter-tile on the coefficients of friction against time at a constant sliding speed is considered. Micromechanical tests were carried out using the method of instrumental indentation with a triangular Berkovich diamond pyramid. Tribotechnical tests were performed on a friction machine with a vertical axis of rotation of the spindle according to the scheme “the end of the sample of the fluoropolymer disk is the end of the counter-flange of the annular sleeve (steel 40Kh)” without lubrication and when the friction pair is lubricated with MGE-10A hydraulic oil. It was found that during friction without lubrication, PTFE samples had the maximum friction coefficients, and F4K20 samples had the minimum friction coefficients when working with 40X steel counter-tiles treated with P180 sandpaper. PTFE-RM (A) samples had the best wear resistance, followed by decreasing F4K20, PTFE – RM (B) and PTFE under friction without lubrication. In the presence of lubricant, the samples of the PTFE standard were inferior in wear resistance to the F4K20 samples, but were 5-7% better than the samples of PTFE-RM (B) and (A), respectively.

Методика розрахунку основних характеристик підшипників ковзання систем і агрегатів автомобілів та аналізу їх трибологічної ефективності

A methodology for calculating the main characteristics of sliding bearings of car systems and units is proposed. The specified methodical approach is important when evaluating indicators of tribological efficiency of couplings of parts, nodes, systems and aggregates and operational reliability of cars as a whole. The bearing activation model makes it possible to formulate measures to increase the tribological efficiency of the couplings of parts and the level of operational reliability of nodes, systems and aggregates, and cars as a whole. In addition, the parameters of the actuation model also respond to friction modes. It is shown that it is possible to increase the tribological efficiency of the sliding bearing by means of design, technological and operational methods. The main formulas that make it possible to develop algorithms for calculating a set of bearing characteristics are presented: contact pressure, stress, strength, sliding resistance, wear, resource. For this purpose, the following values are used: compliance coefficients and relative load, contact angle, contact pressures, contact displacements, and the stress state in the contact zone. The geometric and power parameters of the bearing are involved in the developed methodology and algorithm. Modes of friction and the nature and magnitude of the load on the bearing are also taken into account. An algorithm for calculating auxiliary and main characteristics of a sliding bearing has been developed. The conditions of continuity and equilibrium in contact are clarified. The differential-integral equation of the operation of the bearing is obtained and the dependence of the current contact angle on the friction path and other parameters of the sliding bearing operation model is obtained. It is shown that the tribological efficiency of sliding bearings is established by the method of comparative analysis of tribotechnical characteristics determined by the results of tests on friction machines and a stand.

Французские научные инструменты в Музее М. В. Ломоносова МАЭ (Кунсткамера) РАН

The collection of scientific instruments stored at M. V. Lomonosov’s museum at MAE (Kunstkamera) RAS is a unique assemble of material historical sources presenting the history of world sciences at the period of encyclopedism. The article contains the detailed characteristics of seven scientific instruments (sundials, clock, telescope, electrostatic machine) – the technique description, date, specifics of practical usage, by the opportunity – biographic data of experts. The introductory part is devoted to the specifics of French scientific instruments making business in the 18th century – its incompetence in comparison with British, Swiss and German ones emanating from political circumstances and religious attitudes; from the other point of view French instruments are distinguished by refined decoration – luxury not typical for any other nation. The conclusion contains enlightenment potential of the collection under consideration.

Beyond the Rocket: A Review of Propellantless Propulsion Technologies and Concepts

For decades, the dream of unfettered space travel, free from the constraints of traditional chemical rockets, has captivated humanity's imagination. The realization of an interstellar faring civilization hinges on breakthroughs in space propulsion that transcend the limitations imposed by current chemical rocket technology. Scientists explore the intriguing realm of propellantless propulsion, a futuristic vision for space exploration that transcends the limitations of conventional propulsion. The article explores the historical roots of this field, including controversial concepts like the EmDrive and the Biefeld-Brown effect. It further examines theoretical frameworks encompassing asymmetric electrostatic pressure generation and even spacetime warping. However, the quest for reactionless motion faces a fundamental hurdle – the law of conservation of momentum. Efforts to circumvent this law involve manipulating the enigmatic quantum vacuum or creating asymmetric thrust generation within the spacecraft itself. While challenges like precise microthrust measurement, immense energy demands and material limitations persist, the potential rewards are truly transformative. Interplanetary voyages completed in significantly shorter timeframes and drastically reduced launch costs could be attained. Propellantless drives hold the potential to overcome numerous obstacles that current chemical propulsion cannot. This article underscores the critical need for continued exploration through rigorous experimental verification, the development of robust theoretical frameworks and collaborative efforts between physicists, engineers and materials scientists. This continued exploration necessitates the exploitation of existing high-efficiency solar collection technologies. Furthermore, investigations into innovative approaches, such as those utilizing metamaterials, could be pivotal in unlocking the transformative potential of propellantless propulsion systems.

МОДИФИКАТОРЫ ТРЕНИЯ В СМАЗОЧНЫХ МАТЕРИАЛАХ – ЭФФЕКТИВНЫЙ ИНСТРУМЕНТ ПОВЫШЕНИЯ ЭНЕРГОЭФФЕКТИВНОСТИ ДВС

In today's world, energy efficiency is one of the key factors in the development of technologies. Particular attention is paid to internal combustion engines (ICE), which are actively used in various industries and transport. Since overcoming friction consumes up to a quarter of the energy resources consumed, one of the promising tools for improving the energy efficiency of these engines is the use of friction modifiers in lubricants. The article considers the main types of antifriction additives with a brief description of the mechanisms of their action, the main advantages and disadvantages, tested the most common friction modifiers of different nature in the composition of 10w-40 API CI-4 oil on the friction machine 2070 SMT-1 and quantitatively shows the difference in the effectiveness of the selected additives, made conclusions about the most effective additives and dosages of input, as well as the factors limiting the introduction of lyophilic molybdenum modifiers.

ТРИБОТЕХНИЧЕСКИЕ ХАРАКТЕРИСТИКИ СМАЗКИ «ЛИТОЛ-24» С ДОБАВКАМИ ГЕОМОДИФИКАТОРОВ ТРЕНИЯ И ГРАФЕНА

In the technical service of machines and equipment, additives to lubricants are used that reduce the coefficient of friction and wear, and extend the life of tribocouplings. The article examined the tribological characteristics of the Litol-24 grease with additives of a friction geomodifier and graphene. (Research purpose)To evaluate the prospects for using a friction geomodifier and graphene in the commercially produced lubricant “Litol-24”. (Materials and methods) Litol-24 grease, manufactured in accordance with the state standard, was used as the base lubricant. Penetration and dropping point were determined using standard methods. Laboratory tests for wear resistance were carried out on a friction machine 2070. Bench tests - on a specially designed pilot plant, on serial rolling bearings. During the tests, the bearing temperature, noise level, friction torque, and radial clearance were monitored. (Results and discussion) Experimental studies have shown that the combined introduction of a friction geomodifier and graphene in an amount of 0.2 percent leads to a greater reduction in wear (by 9.7 percent) and temperature (by 19.3 percent), and the friction moment in the contact zone in comparison with only one geomodifier. The study established that the dropping temperature remained constant with increasing concentration of fillers. When controlling mechanical losses with an experimental connection, a reduction in the friction moment of bearings by 11.1-12.5 percent was achieved. (Conclusions) The introduction of a friction geomodifier and graphene into the Litol-24 grease makes it possible to reduce wear, the coefficient of friction, the temperature in the mating zone of parts, operating costs and increase the durability of the bearing.

Prediction of the “Screw-nut” gear life

A method has been developed for predicting the service life of a screw pair nut with a large thrust thread, which is based on the energy theory of wear. Based on the results of finite element modeling using the DEFORM-3D software package, the dependence of the change in normal pressures on the contact surface of the nut with the screw along the height of the thread projection was established. Using the SMTs-2 friction machine, a series of experiments was carried out and the coefficient of friction and the energy index of wear intensity were determined for bronze of the brand BrA9Zh3L, used in the manufacture of nuts for screw mechanisms with coarse threads. The calculation of the service life of the nut of the pressure device of the rolling stand of the hot rolling mill 2000 has been performed. The limit value of the number of revolutions of the screw is established, the excess of which leads to critical wear and destruction of the threads.

МОРФОЛОГИЧЕСКИЕ И ТРИБОЛОГИЧЕСКИЕ СВОЙСТВА МЕХАНОАКТИВИРОВАННОГО MOS2, ИСПОЛЬЗУЕМОГО В КАЧЕСТВЕ ПРИСАДКИ ДЛЯ МОТОРНОГО МАСЛА

The issues of improving the operational parameters of internal combustion engines are given a lot of attention, and in this regard, the direction related to improving the quality of engine oil with the help of dispersed additives is of great importance. In the article morphological and tribological properties of mechanically activated MoS2 used as an additive for semi-synthetic engine oil are considered. The obtained materials were investigated by the method of electron (scanning) microscopy, and the distribution of MoS2 particles as an additive in motor oils was analyzed, as well as IR spectroscopy of the material before and after mechanoactivation was carried out. Comprehensive comparative studies of tribological parameters (friction machine MI-1M) (running-in time, running-in wear, friction coefficient ratio, established friction coefficient and total wear) of motor oil with and without MoS2 additive were carried out. The mass concentration of MoS2 in the engine oil (Mannol Semi-synthetic Classic 10W-40), varied from 0.03 to 0.07 with a step of 0.02 wt.%. It was found that the addition of MoS2 to the engine oil reduces wear from 5.7 to 4.1 microns, with a decrease in the steady-state coefficient of friction from 0.115 to 0.08, which follows from the decrease in the steady-state coefficient of friction from 0.115 to 0.08. The time during which the working-in process increases from 1.57 to 2 h, which also reflects the reduction of friction when using engine oil with MoS2 additive. At the same time during operation the concentration of MoS2 additive in engine oil decreases, which leads to deterioration of properties. So, reduction of concentration from 0.07 to 0.03 (change by 57%) increases wear from 7.7 to 7.90 microns, which is 2.5%, and when reducing the concentration from 0.07 to 0.05, the increase in wear is 1.2%. Thus, considering the factors related to filtration, accumulation effect and the values of the studied typological parameters, a MoS2 concentration in the range of 0.03 to 0.07 wt.% is optimal.

Ultrahigh power generation from low-frequency and micro motion by suppressing air breakdown

This work reports a novel and standard metric of plot to evaluate the electrostatic generator's output performance under air breakdown limitation and proposes a strategy to extend the plot for achieving ultrahigh power generation.

(Invited) Some Observations on the History of Electrochemistry in Europe

Modern electrochemistry is generally regarded as having its origins in the work of the Italian scientists Galvani (1737 – 1798) and Volta (1745 – 1827). Their discoveries led directly to the invention (1799) by Volta of the voltaic pile, a primitive form of what we now call a battery. This invention greatly facilitated electrical experimentation and quickly led to a host of other electrochemical discoveries such as the electrolysis of water (Nicholson and Carlisle in 1800, although it was first demonstrated in 1789 by Deiman and van Troostwijk using an electrostatic generator), isolation of elemental alkali and alkaline earth metals (Davy, 1807–1808) and electroplating (Brugnatelli, 1805). The work of Davy (1778 – 1829) and of Faraday (1791 – 1867) greatly advanced the understanding of electrochemistry and Faraday’s laws of electrolysis (1833) put the field on a quantitative basis. This was followed by a long succession of electrochemical discoveries that has continued to the present.Scientists such as Daniell (1790 – 1845), Grove (1811 – 1896), Leclanché (1839 – 1882) and Planté (1834 – 1889) made early improvements to batteries; of course, research and development of batteries remains an important area of electrochemistry. Historically, batteries were the primary source of electric current until practical electric dynamos became available in about 1870. Electroplating developed as a practical technology from about 1840, initially for electrodeposition of copper on printing plates. From 1893 to 1948, the international standard for electric current was based on electrodeposition of silver. Furthermore, an electrochemical cell invented by Weston (1850 – 1936) was adopted as the reference standard for voltage in 1903 and remained so until 1990 when it was replaced by a Josephson junction standard.The science of electrochemistry experienced rapid growth from the 19th century on, with major contributions from European scientists including Kohlrausch (1840 – 1910), Ostwald (1853 – 1932), Arrhenius (1859 – 1927), Tafel (1862 – 1918), Nernst (1864 – 1941), and Heyrovský (1890 – 1967), to mention but a few. In this talk, I will attempt to trace the evolution of electrochemistry and discuss some of the major landmarks and the European scientists who made important contributions. I will also comment on how equipment and methodology have changed over the last half-century.

МОДЕРНИЗИРОВАННАЯ МАШИНА ТРЕНИЯ

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.

ИССЛЕДОВАНИЕ ТРИБОТЕХНИЧЕСКИХ СВОЙСТВ КОМПОЗИЦИОННОГО МАТЕРИАЛА НА ОСНОВЕ АЛЮМИНИЕВОЙ МАТРИЦЫ АРМИРОВАННЫЙ СТАЛЬЮ ИЛИ БАЗАЛЬТОМ

The study objective is to evaluate the tribo-engineering properties of composite materials based on an aluminum matrix reinforced with steel or basalt in comparison with a material without reinforcement, and to develop a technology for obtaining such composite materials. Frames consisting of multidirectional fibers were used as reinforcing components: basalt wool (175-200 kg/m3 density); steel wool (4# class); melting temperatures of steel and basalt, which make up steel and basalt wool, are above 10000C, which makes it possible to pour aluminum without changing the aggregate state of reinforcing frames. The percentage of reinforcing components by weight is 4-5%. Deformable AB aluminum alloy was used as a matrix, which differs from the alloys of Al-Mg-Si system because of its higher level of tensile and yield strength. The composite materials under study were obtained by the liquid–phase method - casting according to melting models. Tribo-engineering properties were tested on a friction machine in the medium of Lukoil standard 10W40 SF/CC engine oil. To determine the anti-wear properties, tests were carried out for 1 hour, and to determine the antisize properties and the seizure load, tests were carried out with a constant increase in the load on the friction unit. The assessment of anti-wear and antisize properties was carried out by comparing the values of wear spots and seizure loads. It is found that the anti-wear properties increase by 76-85% when reinforcing samples with basalt wool and by 46-76% when reinforcing with steel wool in relation to an unreinforced sample. Antisize properties increase with basalt reinforcement by 23%, and decrease by 7% with steel reinforcement. Studies on assessing tribo-engineering properties of samples obtained by casting from AB aluminum alloy reinforced with basalt and steel have shown an improvement in anti-wear and antisize properties in relation to samples from AB alloy without reinforcement.

МАСЛЯНЫЕ СОЖ ДЛЯ ОПЕРАЦИЙ ПРОТЯГИВАНИЯ С УЛУЧШЕННЫМИ ТРИБОТЕХНИЧЕСКИМИ И ОХЛАЖДАЮЩИМИ ХАРАКТЕРИСТИКАМИ

The paper objective is to test the developed lubricoolants of domestic production for broaching operations instead of imported analogues. The results of comparative laboratory tests of new technological lubricoolants Rosoil-V9 and Rosoil-423M for broaching operations, which are analogues of imported coolant, are presented. Laboratory tests are carried out in the Laboratory for Testing Technological Lubricants of Self-supporting Creative Center of Ufa Aviation Institute. Tribo-engineering properties are determined on a four-ball friction machine according to GOST 9490-75; cooling characteristics are determined on UZS-2 installation. The physicochemical properties are evaluated by standard test methods. As a result of the conducted research, it is found out that the physicochemical properties of Rosoil lubricoolants are similar to imported ones, and in terms of tribo-engineering and cooling characteristics, Rosoil lubricoolants are better than imported analogues.

ОХЛАЖДАЮЩИЕ И ТРИБОТЕХНИЧЕСКИЕ ХАРАКТЕРИСТИКИ МАСЛЯНЫХ СОЖ

The paper presents the results of studies aimed at defining the effect of the cooling properties of oil lubricants used in various metalworking processes. The design and a brief description of the installation are given, which allows to obtain temperature-time, temperature-velocity dependencies of various liquids. The use of this installation gives the opportunity to select lubricants according to its cooling properties, depending on the temperature range required by the process. The assessment results of lubricant cooling properties at UZS-2 installation, manufactured according to the requirements of international standards ISO 9950, ASTM D6200 - 01 and ASTM D6482 – 06 are presented. The dependences of tribo-engineering properties of the tested oil lubricants on their cooling characteristics are found out. It is shown that with an increase in the temperature at which the maximum cooling rate of the lubricant is provided, its extreme pressure and anti-wear properties determined according to GOST on a four-ball friction machine increase.

НОВЫЕ ЛИТИЕВЫЕ ПЛАСТИЧНЫЕ СМАЗКИ С УЛУЧШЕННЫМИ ТРИБОТЕХНИЧЕСКИМИ И АНТИКОРРОЗИОННЫМИ ХАРАКТЕРИСТИКАМИ

The paper objective is to develop new greases with increased load capacity, corrosion protection, which provide lower wear of friction units. The results of comparative laboratory tests of the physicochemical, tribo-engineering and anticorrosive properties of new Rosoil-LS-112 and Rosoil-LS-720 greases in comparison with Litol-24 grease manufactured according to GOST 21150 are presented. All tests to determine the tribo-engineering characteristics and physicochemical parameters of greases are carried out in the accredited Laboratory for Testing Technological Lubricants of Self-supporting Creative Center of Ufa Aviation Institute. As a result of the tests carried out, it is found that Rosoil-LS-112 grease surpasses Litol-24 in tribo-engineering properties determined on a four-ball friction machine. Rosoil-LS-720 grease, in relation to Litol-24 and Rosoil-LS-112 greases, has a bette protective ability in salt fog.

Wear Reduction in Heavily Loaded Units of Transport Vehicles

Introduction. The pivot assembly provides connection between the rotating and non-rotating parts of machines and mechanisms such as cranes, excavators, trailers, railway rolling stocks. In relation to rolling stock, it connects the load-carrying part of the car with the bogie and is one of the most critical and wear-out friction units. Its technical condition affects the intensity and form of wear of the surfaces themselves, the amount of resistance to rotation of the bogie when the car moves in curved sections of the track, the amplitude of the lateral rocking of the car, the intensity of wear of the wheel flanges and, as a consequence, the safety of operation of the rolling stock as a whole. Until now, periodic grease is used for this unit, which, even with a short mileage, manages to be squeezed out of the contact zones and, thereby, creates conditions for the predominance of dry friction. Until now, various proposals to solve this problem have not found application in mass production for a number of reasons, and therefore the search for ways to reduce wear in the pivot assembly of cars is still relevant. This study proposes a solution to this problem that does not require structural changes to the pivot assembly itself. The aim of this work was to develop a technologically advanced anti-friction coating with good adhesion, which will be applied to the surface of a replaceable disk installed between the rubbing surfaces of the pivot assembly during scheduled repairs of the car chassis. This approach will reduce the friction force and wear rate in the unit when lubrication shortage occurs due to squeezing out of the grease. Materials and Methods. Antifriction characteristics of the developed coating was observed on a friction machine providing specific loads on the test sample up to 5000 N and a sliding speed from 0.13 m/s. The samples were examined by scanning electron microscopy (FEI Quanta 200 microscope). SEM images were acquired in a back-scattered electron (BSE) mode using a semiconductor detector. To analyze the elemental composition of beam samples, an energy dispersive spectrometer (EDAX Element EDS system) was used. Results. A three-layer functional phosphorus-containing composite coating of the surfaces of the unit was developed, which made it possible to significantly reduce the coefficient of friction and, as a consequence, the intensity of wear of the pivot unit surface during dry friction. The optimal conditions for obtaining composite coating layers were determined. The influence of the thickness of each layer and the conditions for its production on its functional characteristics was studied. Discussion and Conclusion. The proposed solution is manufacturable and, with appropriate adaptation, can be used to reduce wear in any open pivot assembly without radically changing its design. The methods for producing coating layers are accessible and technologically advanced for serial use.

Carbon nanotube microbeads for enhanced gas heating in a fluidized bed solar air collector

A novel approach utilizing vertically-aligned carbon nanotube (VACNT) as solar heat absorbers is proposed for efficient gas heating in a concentrated fluidized bed solar air collector (FBSAC). The VACNT powder was fabricated into CNT beads suitable for fluidized bed applications through macronization and densification. The CNT bead showed an increase in size and a 6.8 times increase in apparent density. The increase in sphericity and a significant decrease in the repose angle indicated improved particle fluidity. The prepared CNT beads demonstrated an absorptivity similar to VACNT, along with increased thermal conductivity and specific heat capacity, indicating superior thermophysical properties compared to conventional CNTs. Moreover, the reduced electrostatic charge generation minimizes the issue of particle attachment on the transmission window. The heat absorption characteristics of air in FBSAC (50 mm i.d. × 150 mm height) with CNT microbeads were determined. The FBSAC achieved a maximum gas temperature of approximately 150 °C. The CNT bead achieved a higher temperature difference of the gas per irradiance and a more comprehensive operating range of gas velocities up to 0.16 m/s than VACNT. The FBSAC with CNT beads exhibited a maximum thermal efficiency of 30.3 % and higher efficiency of 8–21 % than CNT powders at gas velocity of 0.11 m/s. A correlation was proposed to predict the thermal efficiencies of the FBSACs with different particles from dimensionless numbers considering particles dynamics and thermophysical properties.

Влияние регенерации слоистого модификатора трения на триботехнические свойства смазочных композиций

The paper examines an influence of the regeneration efficiency of the developed anti-wear additive on tribological properties of the lubricating composition, including a lubricating oil and the additive. The anti-wear additive was a layered friction modifier – molybdenum diselenide MoSe2, mixed in the volume of a composition of unsaturated fatty acids – stearic acid and oleic acid. Lubricating oil M-16G2TSS was chosen as the base lubricant, with respect to which the tribological properties of other lubricants submitted for testing are compared. For all cycles of tests, a volume of no more than 25 cm3 of lubricant was used to avoid high thermal inertia when the test samples moved on the friction machine. Experiments of the regeneration of the additive were carried out on a rotary mixing unit of the author's design, and the solution has a long storage period of 8 640 hours (about 12 calendar months). The possibility of restoring the uniform distribution of molybdenum diselenide throughout the volume of the additive in a suspended state has been revealed. This lubricant composition, after restoration of the structure by stirring, can be used in the production of a lubricant composition based on M-16G2TSS oil. Using a reciprocating friction unit of a friction machine, simulating the cylinder-piston group of a marine diesel engine, the resulting lubricant composition was compared with other lubricants based on molybdenum diselenide, the additive solutions of which have different storage periods before being added to the lubricating oil, as well as with the base lubricating oil. The assessment of the tribological properties of lubricants based on M-16G2TSS oil by determining the weight wear and further using this value to estimate the resource of the friction unit has been made. Rotational regeneration has shown satisfactory effectiveness in partially restoring of the tribological properties of a lubricant composition with the participation of an additive, but is not enough effective compared to rotational pulsation mixing of the additive in order to create perspective lubricant compositions.

Particle movement mode effect on electrostatics

In this work, particle electrostatics was studied by experiment methods. A single particle was tested for charge generation through moving along a metal inclined plate. It is found that particle movement mode does an important role in determining electrostatics generation. The sequence of particle movement mode to generate electrostatic charge from high to low is sliding, sliding-rolling and rolling. Particle sphericity determines the mode of particle movement along the inclined plate. The electrostatics generated decreases with increasing sphericity. Such trend becomes less from sliding to rolling and decreases with increasing the plate inclination. The electrostatics generated decreases with increasing the inclined angle of the plate, which causes particles more rolling and less sliding. The effect of inclined angle of the plate on the electrostatic charge generation is more significant for a particle with low sphericity than that for a particle with high sphericity. In addition, a granular pneumatic conveying system was set up to measure the electrostatics generated by multiple particles, where particle movement mode is found to make an obvious effect on electrostatic charge generation. Due to particle–wall contact area being large, sliding particles can generate more electrostatic charge than rolling particles do. It is found that electrostatics increases with particle size, particle loading and pipe length.