Surface Layer Of Metal Research Articles

PROBABILITY OF ELECTRON TUNNELING THROUGH DIELECTRIC PORES IN SURFACE METAL LAYER

The paper presents a study of the influence of nanovoids formed in the metal surface layer on the field emission current (the first stage of the accelerator structure breakdown). It is shown that the field emission current through nanovoids has a resonant character. It was found that under resonant conditions, an increase in the current density from the copper surface by more than 3.5 times compared to the case of an unmodified surface is observed. The presence of a dielectric in the nanovoids expands the resonant region. When the resonance conditions are not met or the diameter of the nanovoids increases, the current density decreases to zero, which can be a way to prevent an accelerator structure breakdown.

Microstructural characterizations of metallized Al2O3 before/after surface treatment and Al2O3/Cu soldered joint

Joining Al2O3 ceramics to Cu heat pipes should be conducted at low temperatures since Cu heat pipes may fail at temperatures higher than 320 °C. Due to the poor wettability of low-temperature solder on Al2O3 ceramics, it is essential to metallize Al2O3 ceramics before joining Al2O3 to Cu with a low-temperature solder. Surface metallization of Al2O3 has been conducted using Ag-Cu-Ti active metal filler at 900 °C. Microanalysis indicates that an interfacial reaction occurs between the active metal filler and the Al2O3, leading to the formation of a Cu3Ti3O reaction layer. The metal layer on the surface of Al2O3 is primarily composed of Ag (s, s) (solid solution), Cu (s, s) and Ti2Cu. The polishing treatment of the surface metal layer in metallized Al2O3 results in a reduction of the oxide content and contaminants, which subsequently allows joining at low temperature. Low-temperature joining of metallized Al2O3 to Cu has been carried out using Sn-Ag-Cu solder at 280 °C. The joining area of the joint includes a Cu3Ti3O reaction layer, a metal layer and a solder layer. The solder layer mainly consists of Sn (s, s), Ag3Sn and Cu6Sn5. The Al2O3/Cu joint fractures in the solder layer after the shearing test, indicating that the strength of the solder is relatively low. However, the interfacial bonding between the metallized Al2O3, solder layer and Cu base material is satisfactory.

Influence essential of current on electrochemical plasticization of single-crystal copper

Despite the long-standing identification of electrochemical plasticization (EP) in the metal surface layer, the mechanisms governing the impact of electric current density on EP remain incompletely understood. This study investigates the effect of current density (ranging from 0 mA cm−2 to 10.0 mA cm−2) on EP during electrochemical cold drawing of single-crystal copper in a 0.35 mol L−1 dilute H2SO4 electrolyte through microstructural characterizations and reactive force field molecular dynamic simulations. The results indicate that with increasing density, more atoms in the high-energy {110} and {001} planes in the copper surface are selectively dissolved, causing the atoms in the low-energy uncorroded {111} planes to become more loosened. This activates more abundant dislocations in a multi-slip way, thereby facilitating dislocation entanglements to reconfigure into movable short-range wavy dislocations and decreasing dislocation density through reactions, ultimately resulting in improved EP. However, when the density exceeds 6.7 mA cm–2, an opposite effect is observed due to the dissolution of fewer atoms resulting from enhanced local passivation.

Effect of Surface-Active Media on Contact Elastoplastic Deformations of Surface Layers of Metals and Their Tribological Characteristics

Effect of Surface-Active Media on Contact Elastoplastic Deformations of Surface Layers of Metals and Their Tribological Characteristics

Study of the relationship between the strength limit and long-term fatigue of steel reinforcement of reinforced concrete structures with a long servise life in aggressive environments

It is known that the fatigue process begins with plastic deformation of the surface layers of the reinforcement metal. Moreover, the movement of dislocations in the conditions of repeatedly alternating stresses is observed at loads below the elastic limit of the metal. The rate of local plastic deformation during cyclic deformation is several orders of magnitude higher than the rate of deformation under static loading. Slip of dislocations begins in grains with a favorable orientation near the stress concentrators. With an increase in the number of cycles in the surface layers, the density of dislocations and the number of vacancies increases. When the basic number of NR cycles is reached, a surface hardened metal layer is formed with a large number of seed cracks, the size of which does not reach a critical value. An increase in the number of cycles cannot cause further development of destruction in such a layer. Only when the stresses exceed the endurance limit do the cracks reach a critical length, after which the process of their draining into the main crack begins with the propagation of the latter. The results of experimental studies indicate a strong influence of diffusible hydrogen on the static and cyclic parameters of crack resistance. It was established that with the increase of flooding, especially when the hydrogen content exceeds 5 cm3100g, both the static strength and long-term strength (fatigue-laziness) decrease sharply. Moreover, these areas of the hydrogen solution in the reinforcing steel are characterized by a viscous nature of fracture, while for heavily flooded reinforcement (from 5 to 12 cm3100g, brittle fracture by the mechanism of micro-split in the hardened (martensitic or troostite structure) is inherent. The analysis of the obtained experimental results made it possible to determine the optimal content of hydrogen in reinforcing steel (3-5 cm3 100g), the excess of which will cause a decrease in the crack resistance of the reinforcement in the process of long-term operation, especially in corrosive and aggressive environments. The issue of fatigue of reinforcing steels is very relevant today.

RESEARCH ON THE RELATIONSHIP BETWEEN THE THICKNESS AND THE STRUCTURAL CONDITION OF ROLLED METAL FROM LOW-CARBON LOW-ALLOY STEEL 10G2FB

When choosing steels for the design of high-rise and long-span buildings with increased load-bearing capacity, it is advisable to give preference to thick rolled steel from low-carbon, low-alloy steels, since it, with the same level of strength as construction steels, has a higher level of plasticity. At the same time, the problem of using thick rolled steel from low-carbon, low-alloy steels in the construction industry are the anisotropy of the rolled metal properties, which can increase with an increase in the thickness of the rolled metal. Currently, in Ukraine, controlled rolling is one of the most promising technologies of high-temperature thermomechanical processing for the production of thick rolled metal from low-carbon, low-alloy steels. At the same time, with an increase in the thickness of the rolled metal, which is produced with this technological scheme, the effect of the regulated formation of the structural state decreases due to the influence on the temperature of the surface layers of the rolled metal, the thermodynamic state of the inner layers and the inability of the rolling equipment available at domestic enterprises to deform the metal over the entire cross-sectional area. Therefore, the task of obtaining such a structural state in the thick sheet metal roll, which will ensure the reduction of the anisotropy of the properties, which will allow the use of such rolled metal in the construction industry, is urgent. Purpose of the article is to study of the structural state of low-carbon low-alloy steel 10G2FB, which was produced using the technology of controlled rolling, depending on the thickness of the rolled metal. Conclusion. The relationship between the structural state and the thickness of rolled metal from low-carbon low-alloy steel 10G2FB, which was produced by controlled rolling technology, was studied. It was established that with the increase in thickness, the percentage content of the ferrite component increases with a simultaneous decrease in the percentage content of the pearlite phase. It is shown that changes in the formation languages of structural components begin with an increase in the thickness of the rolled metal over 30 mm, which is explained by the influence of the temperature of the inner layers on the processes of forming the structural state, namely, with an increase in the thickness of the rolled metal, the thermodynamic rate of phase transformations in the middle layers of the rolled metal samples decreases. This conclusion is confirmed by two factors: firstly, an increase in the size of pearlite colonies, and secondly, a change in the morphology of the cementite framework of pearlite colonies from zigzag (thickness 16...30 mm) to ribbon (thickness 40...100 mm).

Magnetohydrodynamic Instability of the Surface Metal Layer Melted by Pulsed Current

Magnetohydrodynamic Instability of the Surface Metal Layer Melted by Pulsed Current

Tribological and Chemical–Physical Behavior of a Novel Palm Grease Blended with Zinc Oxide and Reduced Graphene Oxide Nano-Additives

The role of industrial lubricants in machinery is to reduce friction and wear between moving components. Due to the United Nations’ tendency to reduce dependency on fossil fuel, a general awareness is strongly driven towards developing more eco-friendly lubricants. Palm oil possesses promising properties, which promote it to be a competitive alternative to the hostile mineral oils. Still, marginal oxidation stability, viscosity, and tribological properties remain critical issues for performance improvement. This paper presents an improved palm grease using reduced graphene oxide (rGO) and zinc oxide (ZnO) nano-additives at different concentrations. Oil and grease samples were tested for viscosity, oxidation stability, pour point, penetration, roll stability, dropping point, churned grease-oil release, copper corrosion, friction, and wear. ZnO additives enhanced the oxidation stability by 60% and shifted the pour point to 6 °C. Adding ZnO and rGO to the palm grease increased the load-carrying capacity between 30% and 60%, respectively, and reduced the friction coefficient by up to 60%. From the wear scar morphologies, it is believed that graphene 2D nanoparticles formed absorption layers which contributed to the increase in load-carrying capacity, while ZnO chemically reacted with the metallic surface layer, forming zinc compounds that resulted in a protective boundary lubricating film.

Surface Tension Estimation of Steel above Boiling Temperature

Surface tension is an important characteristic of materials. In particular at high temperatures, surface tension values are often unknown. However, for metals, these values are highly relevant in order to enable efficient industrial processing or simulation of material behavior. Plasma, electron or laser beam processes can induce such high energy inputs, which increase the metal temperatures to, and even above, boiling temperatures, e.g., during deep penetration welding or remote cutting. Unfortunately, both theoretical and experimental methods experience challenges in deriving surface tension values at high temperatures. Material models of metals have limitations in explaining complex ion interactions, and experimentally measuring temperature and surface tension at high temperatures is a challenge for methods and equipment. Therefore, surface wave analysis was conducted in this work to derive surface tension values around the boiling temperature of steel and identify trends. In addition, a simple ion interaction calculation was used to simulate the impacting parameters that define the surface tension. Since both the experimental values and simulation results indicate an increasing trend in surface tension above the boiling temperature, it is concluded that the dominating attractive forces above this temperature should increase with increasing temperature and lead to increasing surface tension forces in the surface layers of liquid metal.

Dual-Band Large-Frequency Ratio Power Divider Using Mode Composite Transmission Line for 5G Communication Systems

In this paper, a novel kind of mode composite transmission line (MC-TL) is proposed, and a dual-band power divider with a large frequency ratio using this novel MC-TL for 5G communication systems was developed. The proposed MC-TL was developed using spoof surface plasmon polaritons (SSPPs) and a corrugated substrate-integrated waveguide (CSIW) transmission line, which supports both a surface plasmon mode and TE10 mode, independently. The surface plasmon mode operates in the grooves of the surface metal layer, while the TE10 mode works in the substrate between two metal layers. These two parts can transmit different modes at independent frequencies. This structure can be used in dual-band transmission lines with a high frequency ratio. The characteristics and design of the MC-TL (SSPPs and CSIW) are analyzed and illustrated. The MC-TL was fabricated and measured to demonstrate its performance. Moreover, based on the proposed MC-TL, a dual-band power divider with a large frequency ratio (operating at 3 GHz and 28 GHz simultaneously) was also designed and fabricated. It can cover the frequency of a fifth-generation communication system perfectly. The measured outcomes align closely with the simulated results, demonstrating robust agreement and showcasing excellent transmission capabilities.

Laser Surface Transformation Hardening for Automotive Metals: Recent Progress

This article discusses recent advancements in the Laser Surface Transformation Hardening (LSTH) process applied to industrial metals. It focuses on examining the microstructure of the metal surface layer and explores different methods of performing LSTH to evaluate mechanical and surface properties. The study also investigates the utilization of various industrial lasers and simulation software for the LSTH process. The careful analysis of heat transfer and temperature control during LSTH aims to prevent the generation of surface defects like micro-cracks and surface melting. Finite element method (FEM) software effectively simulates the LSTH process. The research provides a comprehensive overview of recent developments in LSTH, categorized based on different metals and subsequent testing, highlighting its applications in the automotive industry. Electrochemical, wear, and microhardness tests are investigated to assess the potential applications of automotive metals.

Удосконалення механізму притирання вільним абразивом за допомогою використання силікатного складу

The results of an experimental study are presented that explain and confirm the mechanism of lapping friction surfaces with a silicate abrasive composition.
 It is shown that the stability of the silicate lapping paste over time can be achieved by introducing ferric trichloride (FeCl3), which in this case is a thickener of liquid glass and also has high hygroscopic properties. The adhesive properties of the silicate paste are improved by the addition of lubricant 1-13. This grease was chosen due to its water solubility. To increase the abrasive ability of the silicate paste, an abrasive powder was introduced. 
 It was found that the lapping performance of the silicate composition and the quality of surfaces are higher than when treated with the «KT» paste, which is currently used for lapping automobile engine valves. Based on the results of the study, the mechanism of lapping friction surfaces with a silicate paste is presented. The mutual movement of the surfaces results in cutting and scratching of the highest peaks of the bumps by the abrasive grains. When silicon oxide (SiO2) is added to the abrasive material, its particles are coated with silicon oxide. This is because liquid glass solutions have a high adhesive force and low surface tension. At the points of contact between the abrasive particles, the temperature rises, and since there is SiO2 around the abrasive, when the latter enters the contact zone, amorphous silica (SiO2) is formed. Since the abrasive grains are coated with a silicon oxide film, SiO2 penetrates into the cavities of micro-irregularities and adheres to the surface under repeated exposure to the abrasive. Thus, the surface to be treated is saturated with silicon oxide, which leads to an increase in its quality after grinding with a silicate composition.
 It has been proven that high surface quality is formed by amorphous silica. To confirm this mechanism, chemical and X-ray spectral analyses of the samples were performed, which showed the presence of SiO2 on the treated surface and a "strong bond" of silicon compounds with the metal surface layer. 
 It was found that the high quality of the surface is also due to the shape of abrasive particles and wear products. It has been confirmed that with the variable movement of surfaces relative to each other, abrasive grains take on a new position each time. At the same time, they are worn from all sides and acquire a rounded shape, and are simultaneously enveloped by a SiO2 foil.

Effect of the surface status on corrosion fatigue of the strained structural materials

Fatigue failure of metal structures during operation is a frequent cause of machinery and equipment failure, and sometimes of human losses. This is especially true for operating conditions in the presence of corrosive environment. Reliable and safe operation of metal products and engineering devices during operation is largely determined by the structure and properties of the used materials and is ensured by optimizing the process operating conditions. The analysis of domestic and foreign literature data has shown that systematic theoretical and experimental studies of the impact of corrosive environment on the resistance to alternating loads on strained metals and alloys are practically absent. In this regard, the issue of identifying the patterns of corrosion and fatigue failure seems to be urgent in order to increase the corrosion fatigue life of plastically strained metals and alloys. This paper analyzes the impact of the status of surface layers of structural metals in a thermally treated and plastically strained state. The factors influencing the metals oxidation susceptibility have been established. During cyclic loading all processes related to vacancies’ concentration and fatigue cracks nucleation are ahead of schedule in the surface layers of metal, and all structural damage is concentrated at the surface, especially in case of corrosion fatigue. Plastic deformation increases both the thermodynamic possibility of oxide formation on the metal surface and the speed of this process. An increase in the active sites density on the surface of the strained metal contributes to the emerging of a large number of oxide nuclei, the growth of which leads to a faster formation of a continuous passivating film than on the surface of an unstrained metal.

МЕТОДИКА ВОССТАНОВЛЕНИЯ РАЗМЕРНЫХ СВЯЗЕЙ ПРИ РЕГУЛИРОВКЕ КЛАПАННОГО ЗАЗОРА В МЕХАНИЗМЕ ГАЗОРАСПРЕДЕЛЕНИЯ АВТОМОБИЛЬНОГО ДВИГАТЕЛЯ ВНУТРЕННЕГО СГОРАНИЯ

The relevance of research is due to the problems of organizing auto repair production in modern conditions associated with the difficulty of logistics and the high cost of foreign spare parts, which is confirmed by the analysis of domestic and foreign literary sources. Of particular importance in this case are the methods of optimizing the balance of costs for performing repair and restoration actions and replacing defective parts. The purpose of the work is to improve the quality of repair of rolling stock of road transport based on the use of methods for restoring dimensional connections. This study is designed to fill the existing knowledge gap caused by the lack of methods for restoring specific repair links. The use of new parts in repair, along with restored or used ones, necessitates the wider use of methods for optimizing the limit values of wear and recovery processes of dimension chain elements. The materials and methods of research are presented as an example of the development of a technique for restoring the necessary parameters of dimensional connections when adjusting the valve gap value, since the thermal gap in the timing mechanism of an internal combustion engine is an important element affecting the efficiency of the car engine. The scientific novelty of the work lies in the study of two different methods potentially suitable for implementation in the repair industry for restoring dimensional ties while reducing the valve gap by machining the outer or inner contact surfaces of car engine pushers. Studies have been carried out in relation to the decrease in the gap in operating conditions, which is widespread in automobile engines with overhead camshafts, since a decrease in the valve gap to a greater extent than an increase in it affects the efficiency of the machines. The equation of the size chain of the valve group is given, in which the valve gap is the closing link. As a result of sequentially discretely removing the surface layers of the pusher metal at 0.05 mm intervals and measuring the hardness of the surface layers, it has been found that this approach to restoring repair bonds can be recommended for use in auto repair production, with a more preferred method being to adjust the valve clearance by grinding the outer surface of the pushers. The data obtained can serve as the basis for further research in the development of a set of technologies for restoring specific size chains using repair kits that include parts with different manufacturing accuracy or that have been in operation.

Multi-spectroscopic study of electrochemically-formed oxide-derived gold electrodes.

Oxide-derived metals are produced by reducing an oxide precursor. These materials, including gold, have shown improved catalytic performance over many native metals. The origin of this improvement for gold is not yet understood. In this study, operando non-resonant sum frequency generation (SFG) and ex situ high-pressure X-ray photoelectron spectroscopy (HP-XPS) have been employed to investigate electrochemically-formed oxide-derived gold (OD-Au) from polycrystalline gold surfaces. A range of different oxidizing conditions were used to form OD-Au in acidic aqueous medium (H3PO4, pH = 1). Our electrochemical data after OD-Au is generated suggest that the surface is metallic gold, however SFG signal variations indicate the presence of subsurface gold oxide remnants between the metallic gold surface layer and bulk gold. The HP-XPS results suggest that this subsurface gold oxide could be in the form of Au2O3 or Au(OH)3. Furthermore, the SFG measurements show that with reducing electrochemical treatments the original gold metallic state can be restored, meaning the subsurface gold oxide is released. This work demonstrates that remnants of gold oxide persist beneath the topmost gold layer when the OD-Au is created, potentially facilitating the understanding of the improved catalytic properties of OD-Au.

Quantum structure of the surface layer of metals

In this paper, we propose a model for determining the thickness of the surface layer of metals and the quantum structure of this layer. An atomically smooth metal is represented as a diagram: nanolayer → mesolayer → bulk phase, which differ from each other in the nature of size effects. There is no size effect in the bulk phase. The thickness of the surface layer of metals R(I) has a size from 1 nm to 10 nm, except for cesium, i.e. they represent a nanostructure. It is shown that the energy levels En of the nanolayer are determined by one fundamental parameter - the lattice constant of the metal à. As soon as the parameter à stops changing, the spectrum of quantum states passes into a continuous spectrum. The nanolayer R(I) is a step function in En, which can be easily reduced to the Lebesgue integral, which plays an important role in quantum theory. Quantum threads (quantum planes) in the nanolayer R(I) can be interpreted as solitons, crowdions, discrete breathers turning into nanocracks. Quantum threads in the R(I) nanolayer and the nanolayer itself can be represented as a nanoparticle with a diameter of R(I) and pre-melting occurs in it in a stepwise manner. It is finally shown that all metal monolayers differ significantly from each other.

Analysis of Residual Stresses in Curved Cutouts of Steel Box Girder Transverse Diaphragms

In order to analyze the characteristics of cutting residual stress distribution at the arc‐shaped cutout of steel box girder diaphragm and to study its fatigue cracking mechanism. Taking Xia Zhang Bridge as the engineering background, this paper proposes a systematic method for calculating the residual stress field at the arc‐shaped cutout of the diaphragm. First, a mathematical model of the cutting heat source was established for predicting the temperature field changes during the cutting process of the diaphragm. Then, a 3D thermoelastic‐plastic finite element model was established using Abaqus to parametrically analysis the residual stresses during the fabrication of the transverse spacer. The results show that the cutting heat source creates a “thermal stagnation” effect at the curved notch, which leads to the local metallurgical transformation of the metal surface layer, which is unfavorable to its fatigue performance. The residual stresses are mainly concentrated near the cutting line, and the transverse residual stresses are lower at the free edge of the cutting line, which is easy to crack, and higher in the middle of the arc section of the arc notch. Inside the transverse bulkhead, at 14.5 mm from the free edge of the cut, in addition to the existence of high longitudinal residual tensile stress, its transverse residual tensile stress is also high, with a peak value of 199.3 MPa. Thermal cutting produces high residual tensile stress at the free edge, and the tensile stress cycle formed under the combined effect of wheel load is one of the reasons for the formation of initial fatigue cracks.

Analysis of the influence of electrospark alloying parameters on the structural state of alloyed surfaces

Рroblem. Among the promising methods of surface hardening and modification are techniques based on the treatment of metals and alloys with high-energy flows of materials and energy. Among the modern methods of metal surface treatment is electrospark alloying (ESA), which allows obtaining surface structures with unique physical, mechanical and tribological characteristics. It is known that alitization provides metal surface layers with protection against corrosion and oxidation at elevated temperatures. The traditional method of forming alitized coatings is chemical-thermal treatment. The paper proposes a method of alitization by ESA. Many parameters influence the formation of the layer during alitization by the ESA method. First of all, it is the energy parameters. Goal. The aim of the work is to evaluate the effect of the ESA alloying process performance on the structure formation. Methodology. The study was carried out on samples of steel 20. An aluminium electrode in the form of a wire was used as a tool electrode for ESA. Different alloying modes were investigated, the discharge energy and performance were changed. The alloying was carried out in two stages. At the first stage, the aluminium electrode was used at classical performance values. At the second stage, the capacity was reduced by two and four times. At the second stage, a saturating paste containing aluminium powder was applied to the surface before the ESA. The microstructure of the obtained modified surfaces was examined under an optical microscope, the surface roughness and microhardness distribution in the surface layer were determined. Results. The use of two-stage alitization increases the microhardness of the hardened layer and the diffusion zone, as well as reduces the surface roughness. The coating integrity was 100%. (originality) A new method of alitisation based on ESA is proposed, which allows to obtain 100% continuity with high adhesion to the substrate. Рractical value. For practical implementation, it is recommended to perform alitization according to the following variant: the first stage is ESA with an aluminium electrode with a discharge energy Wp = 4.6-6.8 J, the second stage is the application of a saturation paste containing aluminium powder and graphite powder. Electrospark alloying should be carried out with a reduced productivity by about two times.

Mechanism of phase segregation in ilmenite oxygen carriers for chemical-looping combustion

The solid particle of oxygen carrier (OC) plays a vital role in chemical looping combustion (CLC) for fossil fuel combustion and inherent carbon capture. Phase segregation or active metal surface layer formation upon redox cycle had been recently noticed to be a predominant factor causing complete failure of OCs. To explored and identified the mechanism behind rapid phase segregation and external iron-rich shell formation of ilmenite OCs during CLC process, this study investigated into OCs’ phase and element distributions, and surface layer morphologies at various redox cycles, and the cross-sectional microstructures of oxidizing OC particles with different exposure times. The detailed information on the exterior Fe-rich shell formation and the progression of phase segregation were visualized, which provided vital information for the new mechanism of rapid Fe phase migration. The new finding ruled out Kirkendall effects or the ionic diffusion mechanism. The immediate formation of surface layer was found to initiate the segregation of Fe2O3 form TiO2 phase. The rapid Fe phase migration was attributed to the driving force arising from the increased local pressure of particles and the violent exothermic oxidation on reaction front. The strong driving force could directly eject iron-containing phases from the reaction front to surface layer. In the new mechanism, different phases separated inside the reduced OC particles provided the vital intermediates for the starting points of deep phase segregation or rapid surface layer formation; O2 dissociation of on the metallic Fe outmost layer and the oxygen ion conduction in TiO2 phase seemed to provide a short-circuit diffusion pathway for particle oxidation. Finally, this study also explored the strategies that might succeed in improving the integrity of ilmenite OC particles.

Mechanisms of formation of wear-resistant dissipative structures in non-stationary lubrication conditions

The work aimed to determine the influence of the processes of supramolecular self-organization in the lubricating layer on the patterns of wear of friction pairs. The mechanisms of structural adaptability of tribocoupler elements were analyzed, and the regularities of the manifestation of a large-scale and energy jump, which characterizes the transition of the tribosystem to a metastable state, were determined. An evaluation of the tribotechnical characteristics of commercial transmission oils was carried out on a software-hardware complex that, using a roller analogy, simulates the operation of gears in conditions of rolling with slipping. It was established that the activation of contact surfaces in the mode of frequent starts and stops leads to active interaction of the lubricant's components and the metal's surface layers with the gradual formation of boundary adsorption layers. For transmission oil 'Bora B' T-Shyp, an increase in anti-friction properties has been established due to the effective lubricating ability of the oil when forming the hydro- and non-hydrodynamic components of the lubricating layer thickness. The effect of the chemical activity of the zinc dialkyl dithiophosphate antiwear additive and the hydrocarbon components of the base of transmission oils on the effectiveness of the formation of boundary films is considered. It was determined that the formation of stable boundary films of the lubricant is the leading process in manifesting their damping properties concerning the localization of elastic-plastic deformation along the depth of the metal. When boundary films are formed on 90-95% of the contact area, the change in the microstructure of the near-surface layers is fixed at a depth of up to 20 microns; when boundary films are formed on 20...50% of the surface area, the spread of elastic-plastic deformation reaches a depth of up to 50 microns. The kinetics of the formation of boundary films by the lubricant and the indicators of the specific work of friction in contact are correlated with the intensity of wear of the contact surfaces