Antifriction Layer Research Articles

Transient shuttle for a widespread neural probe with minimal perturbation

Bioelectronic implants in the deep brain provide the opportunity to monitor deep brain activity with potential applications in disease diagnostics and treatment. However, mechanical mismatch between a probe and brain tissue can cause surgical trauma in the brain and limit chronic probe-based monitoring, leading to performance degradation. Here, we report a transient shuttle-based probe consisting of a PVA and a mesh-type probe. A rigid shuttle based on PVA implants an ultrathin mesh probe in the target deep brain without a tangle, while creating both a sharp edge for facile penetration into the brain and an anti-friction layer between the probe and brain tissue through dissolving its surface. The capability to shuttle dissolved materials can exclude the retracted process of the shuttle in the brain. Complete dissolution of the shuttle provides a dramatic decrease (~1078-fold) in the stiffness of the probe, which can therefore chronically monitor a wide area of the brain. These results indicate the ability to use a simplistic design for implantation of wide and deep brain probes while preventing unnecessary damage to the brain and probe degradation during long-term use.

Technologıcal Methods of Increasıng Bearıng Performance

The tribological characteristics of bearing shells manufactured using various technologies have been studied. The results obtained allow us to determine the most technologically advanced method. One of the main requirements for load-bearing shells is the absence of macrostresses in the surface layers of the load-bearing shells, leading to their destruction. The studies were carried out only in near-surface areas. The results obtained show that there are no macrostresses in antifriction coatings obtained by ion-plasma and galvanic methods. An important feature is the high adhesion strength of the antifriction layers to the base. Adhesion tests were carried out on samples cut from liners obtained by the acoustic method. The greatest adhesion strength is observed with ion plasma coating, it is 22 MPa.

The deformation behavior investigation of a polymers used as a sliding layer in a contact friction unit

The polymers and composites study of is to the present day an actual topic of many research scientists. Experimental studies of antifriction polymer and composite materials are widespread. But analyzing the performance of materials under different conditions does not lose its relevance. This is due to the limited data on the materials behavior in open sources, both statically and dynamically. The article deals with spherical bridge bearing manufactured by “AlfaTech”, Perm, Russia. The bearing includes a steel balancer with a ball segment in contact with the lower steel plate through a spherical protective antifriction layer. The material of the protective layer may vary. Several options for antifriction layer materials both polymer and composite are reviewed in the work. The geometry of structural elements influences its behavior. A particular effect is observed in elements made of plastic. The main part of parameters was considered in this article, such as thickness and physico-mechanical properties of polymer sliding layer. The article considers the value influence of the friction coefficient on the interaction of contact surfaces. It was obtained that the maximum values of contact parameters decrease with increasing sliding layer thickness. The paper deals with the description of viscoelastic behavior of modern polymers and composites used as sliding antifriction layers within.

ЭКСПЕРИМЕНТАЛЬНЫЕ ИССЛЕДОВАНИЯ ПРОЧНОСТИ СЦЕПЛЕНИЯ ТВЕРДОГО АНТИФРИКЦИОННОГО ПОКРЫТИЯ С ОСНОВОЙ

The article presents a detailed study of individual samples of MODENGY solid antifriction coatings. The selected solid antifriction coatings are described, the roughness of the applied coatings is analyzed, and measurements of the thickness of the antifriction layer on the surface of steel samples are given. The methodology for determining the quantitative assessment of the adhe-sion strength of a solid antifriction coating based on GOST 32299-2013 was analyzed and a set of experiments using a bursting machine with a built-in electronic force meter IR 5047-50 was con-ducted. As a result, a quantitative assessment of the adhesion strength of solid antifriction coatings with a steel base was obtained. Conclusions are drawn about the adhesion strength of solid antifriction coatings. Recommendations on their use for automotive equipment are given.

A Study of the Microstructure and Tribological Properties of Copper-Based Cr@graphite Alloy Modified by Nano Cr3C2 and CrC.

Railway switch plates are important components in railroads, and copper-based graphite alloys have potential as substitutes for traditional materials. Graphite as an anti-friction phase could decrease both the friction coefficient and mechanical properties, with an increasing mass fraction for their poor interface bonding strength. Chromium, a multifunctional metal plated on the graphite (Cr@graphite), has solved this problem. Results have shown that a copper-based Cr@graphite alloy is composed of copper as a base, and graphite and Cr compound transition phase as reinforcements. The transition phase is made up of nano Cr3C2 and dispersed CrC, which offers a stable combination with both graphite and copper. The tribological property of copper-based graphite alloy exhibits a steadily decreasing slope with reinforcement content increasing, and the Cr@graphite samples show lower values than the alloy without any coating treatment. Both graphite and chromic oxide play role in antifriction, and are more efficient than graphite alone. Microcutting is the dominant wear method when copper-based Cr@graphite alloy has a 1~4 wt.% reinforcements content; additionally, adhesion wear and oxidation are also generated. When the anti-friction phase increases, the wear mechanism is affected, and fatigue deformation is the dominant wear method at 4~6 wt.% content. The formation of the chromic oxide phase, as well as the graphite phase, control the formation of an anti-friction layer. In that case, the tribological properties are dramatically improved with reinforcement content enhance.

Evaluation of the Performance of PTFE-Composites as Antifriction Layers in Supporting Parts with a Spherical Segment

Evaluation of the Performance of PTFE-Composites as Antifriction Layers in Supporting Parts with a Spherical Segment

The Study of Radius End Mills with TiB2 Coating When Milling a Nickel Alloy

Nickel alloy high-speed processing technology using ball-end mills is characterized by high contact temperature and leads to accelerated tool wear. One of the effective ways to increase its reliability and service life is to modify the surface by applying functional antifriction layers in addition to wear-resistant coatings. Diamond-like carbon is often used as the latter. However, at cutting speed, when a cutting-edge temperature exceeding 650 °C is reached, the material of this coating reacts actively with oxygen in the air, and the sharply increasing adhesive component of wear quickly incapacitates the milling tooth, limiting its performance. Applying a coating of titanium diboride as an antifriction layer on top of nanocrystalline composite nitride coatings with good resistance to abrasive wear can be a solution to this problem. Our experiments have shown that such technology makes it possible to obtain a twofold increase in durability compared to a tool with a diamond-like antifriction coating in conditions when the cutting edge of the tool is subjected to cyclic thermal shocks above 800 °C, and the durability period of the radius end mill is about 50 min.

INCREASING THE WEAR RESISTANCE OF HEAVY LOADED FRICTION UNITS OF ANTI-FRICTION GAS THERMAL COATINGS

Purpose. The purpose of this study is to establish technological conditions and parameters for obtaining materials for improving the performance of machine parts under conditions of heavily loaded friction units due to quasi-tribosystems of gas thermal sprayed anti-friction layers.
 Research methods. Priori data were used in combination with our own scientific developments of the dependences of the influence of the chemical composition of gas thermal sprayed anti-friction layers on the physical and mechanical properties of the surface layer of the material, which is destroyed under tribosystem conditions.
 Results. On the basis of the theoretical and practical scientific research, a set of relevant knowledge has been obtained, which makes it possible to determine the main criteria requirements for obtaining anti-friction layers and graphically describe the characteristics of the alloy and show the correlations of the parameters with each other. The positive role of aluminum as a soft component of anti-friction pseudoalloys, which is well sprayed by thermal metallization at an affordable cost, has been experimentally confirmed. It has been proven that gas thermal coatings in the form of pseudoalloys, consisting of particles with different physical and mechanical properties of materials, can have up to 2–3 times higher wear resistance compared to single-component coatings from materials included in the composition.
 Scientific novelty. Theoretical and practical scientific research with the reproduction of system analysis to increase the resistance to destruction under the conditions of quasi-tribosystems of gas thermal sprayed antifriction layers is given. It is shown that in order to ensure a good running in of the contacting surfaces in the friction zone and particles of hard material with high wear resistance and resistance against sticking with the counterbody, anti-friction pseudoalloys of coatings should contain zones of material particles with lower hardness to comply with the Charpy principle. It has been determined that when spraying composite wires for application as a solid component of anti-friction coatings, it is possible to use particles of alloying elements that form intermetallic compounds or phase components of alloys with a high hardness during melting. A comparative analysis showed that two-component coatings deposited with composite wires are characterized by higher hardness and wear resistance under high contact pressures compared to coatings of the same composition deposited with different types of solid wires.
 Practical value. The obtained results allow, within the framework of technical and technological accuracy, which is necessary in the practical engineering forecasts, to determine the physical and mechanical properties of wear resistant gas thermal sprayed anti-friction layers under conditions of quasi-tribosystems. Thus, in comparison with cast antifriction materials of the same composition, anti-friction layers obtained by thermal metallization have a 1.5–1.8 times higher wear resistance.

Effect of discrete basalt fiber on operational properties of polytetrafluoroethylene

The article examines the effect of discrete basalt fibers on the tribotechnical characteristics of DF-101 polytetrafluoroethylene according to the “disk-pad” scheme under conditions of friction without lubrication. It was established that the introduction of filler leads to decrease in the intensity of wear and the coefficient of friction of the base polymer 1,7 and 360 times, respectively. The improvement of these properties occurs because “anti-friction layer” that is more stable compared to unfilled polytetrafluoroethylene is formed in the process of friction of basalt plastics. As a result, friction occurs according to the “polymer-polymer” scheme. This is confirmed by a profound change in the morphology of the friction surface. For example, deep ploughing furrows and traces of adhesion with the counterbody are observed for polytetrafluoroethylene, while basalt plastics are more resistant to deformations, which, in turn, leads to a reduction of ploughing furrows. A sharp decrease in wear resistance 1,35-3,3 times is observed for basalt plastics containing 30-40 mass.% of fiber. It is probably a consequence of the growth of defects in the volume of the material due to the uneven location of the fiber in the polymer matrix. The confirmation of the presence of defects in the volume of basalt plastics is confirmed by a comparison of the calculated and experimental (hydrostatic) density. It was found that polytetrafluoroethylene loses 10% of its mass at a temperature of 823K, while the temperature of losing 10% of mass increases by 10 degrees for basalt plastic. It was determined that the effective content of the filler in the polymer matrix is 20 mass.%. The obtained basalt plastic (20 mass.% fiber) is recommended in manufacturing rolling and sliding bearings (as anti-friction protection) for tribological units of modern technology operating under the influence of high temperatures, aggressive environments and friction conditions without lubrication.

Tribosynthesis of friction films and their influence on the functional properties of copper-based antifriction composites for printing machines

Abstract This article is devoted to research of the tribosynthesis mechanism of antifriction films and their influence on the functional properties of antifriction composites based on copper alloyed with nickel and molybdenum with the CaF2 solid lubricant additions for operation at rotation speeds of 3,000–7,000 rph and increased loads of 3.0–5.0 MPa in air. Studies have shown that antifriction films are complex, dynamically changing formations on the surfaces of the composite and counterface, developing according to the bifurcation mechanism. The antifriction layer is decisive in the formation of the friction pair's tribological high-level properties, which provide the self-lubrication mode of the friction unit. The formation and permanent presence of the anti-seize film is associated with a balanced wear rate of the film and its constant formation again on these worn areas at rotation speeds of up to 7,000 rph and loads of up to 5.0 MPa. Due to the steady self-lubrication mechanism, the copper-based composite has significant advantages over cast bronze CuSn5ZnPb, which can only work with liquid lubrication in the friction units of printing machines. The performed studies make it possible to choose rational modes for operation of new high-speed antifriction Cu-composites based on the friction films analysis, predicting their high functional properties.

Influence Analysis of Lubricant Recesses on the Working Capacity of the Bridge Span Spherical Bearing

The load on transport and logistics systems is increasing every year. This is due to car park growth around the world. Thus, increasing bridge structure durability is an urgent task for bridge-building companies. This study analyses the contact deformation of spherical bearing elements through an anti-friction polymer layer with different geometrical configurations of recesses for the lubricant, i.e., annular grooves and spherical holes. The material of the anti-friction layer (a modified polytetrafluoroethylene (PTFE)) is modelled within the framework of the deformation theory of plasticity. The procedure of automating the numerical model construction depends on the input parameters, including the thickness of the layer, the basic geometrical parameters of the recesses for the lubricant, and the distance between the rows of recesses, etc. The influence of the arrangement of filling sliding anti-friction layers on recesses for lubricants in the form of spherical holes on the contact deformation behaviour of bridge bearings has been considered. The reduction of lubricant volume in the sliding anti-friction layer with the geometry of recesses in the form of spherical holes ranges from 26 to 48.4%, depending on the filling scheme, has been found. In this case, structures with lubrication recesses in the form of spherical holes have several advantages, including a more uniform distribution of contact parameters in the interface areas of the steel plates with the anti-friction layer, reduction of the maximum level of the plastic deformation intensity, displacements along the normal relative to the free end of the sliding layer, and the settlement of the bearing.

Selection and Identification of a Model of Elasto-Viscoplasticity of the Filled Fluorocomposite according to Free and Constrained Compression Tests

Introduction. Properties of filled composites based on polytetrafluoroethylene allow them to work at high contact pressures, reciprocating nature of shear loads, and in a wide temperature range. Due to this, they are used as antifriction layers of bearing parts with ball segment. To simulate the mechanical behavior of such materials under operating conditions, adequate constitutive equations of elasto-viscoplasticity and methods of their identification according to the data of basic experiments are needed.Materials and Methods. The tensor-linear model of elasto-viscoplasticity should be identified according to the data of tests on free compression of samples. They were subjected to loading up to a maximum deformation of 10 %, allowed to remain, unloaded, and then, a similar loading cycle up to 160 MPa under constrained compression was carried out. The experiment with a composite based on polytetrafluoroethylene filled with 40 wt. % fine bronze, was conducted at room temperature. Tests for constrained compression were performed for two values of the strain rate, and for free compression – for three values of the strain rate in the range of 10-6 – 10-3 s-1. For the description, two models of elasto-viscoplasticity were considered, representing modifications of Swain and Kletschkowski’s models and corresponding to the connection of a viscoelastic or elastic nonlinear viscous element with a plastic or endochronic element. An integral operator with a Kohlrausch kernel was considered as a viscoelastic element.Results. The results of the constrained compression tests made it possible to separate the elastic relationship of volumetric deformations and average stresses from the constitutive relations. The data of free compression cycles at different strain rates were used to determine the material constants of the model. For this purpose, an efficient search algorithm based on the simplex method of minimizing the discrepancy was implemented. Both models discovered the importance of the plastic component (independent of the deformation rate) for a qualitative description of the stress cycling that accompanied the cyclic deformation, as well as their dependence on the strain rate.Discussion and Conclusions. Both models of elasto-viscoplasticity described correctly the behavior of the studied fluorocomposite under loading conditions close to the operating conditions of the antifriction layers of the bearing parts with ball segment. They can be considered as a basis for their further generalization, taking into account the dependence on temperature.

Wear modes in testing the antifriction layer of babbitt B83

In this work, study of wear modes of antifriction layers of B83 babbitt during tribological tests was carried out. The assumed conditions for changing wear modes were determined during testing with a continuous increase in load by analyzing data of changes in the coefficient of friction and temperature near the contact zone. The data obtained made it possible to conduct experiments for a deeper study of the processes occurring in the friction zone. The results of friction experiments and studies by electron microscopy confirmed the correctness of the assumption about the conditions for change of wear modes. Changes in wear modes and wear mechanisms were judged by the behavior of the friction coefficient, the difference in friction surfaces, wear products, and wear intensity. The results obtained will make it possible to determine and recommend the modes of “wear-free” operation of the babbitt alloy.

Comparative Analysis of the Work of Bridge Spherical Bearing at Different Antifriction Layer Locations

The novel results reported here present qualitative and quantitative regularities of the deformation behavior of a spherical bearing with a different location and inclination angle of the antifriction layer. A number of topical problems encountered during the assessment of the performance bearings are considered in the work. The spherical bearings of the bridge span are investigated. Structures are load-bearing elements of transport systems. They perceive thermal power loads from the bridge span. The temperature problem is not considered in this study. In this paper, a comparative analysis of the bridge spherical bearing operation at different antifriction layer locations was performed. Two bearing geometries are considered: the interlayer is pressed in a spherical segment (classical geometry); the interlayer is pressed into a recess located in the lower steel plate. The six modern antifriction materials considered proved suitable to some extent as contact unit sliding layers for various purposes. Additionally, the influence of the inclination angle of the antifriction layer end face on the structure operation for all sliding layer material variants was analyzed. It has been established that the bearing design with an interlayer in the lower steel plate has a more favorable deformation behavior. Changing of the inclination angle of the antifriction layer end face leads to a decrease in the maximum level of contact parameters and deformation characteristics for all the considered structures.

Hydrothermal deposition of MoS2 on electrospark Ti – Al coatings on Ti6Al4V alloy and their characteristics

Antifriction layers on titanium alloy Ti6Al4V can be obtained by creating a developed structure of lubricant pockets, followed by the application of dry self-lubricating substances. The structure and tribological behavior of Ti – Al intermetallic coatings after hydrothermal deposition of molybdenum disulfide (MoS2) have been studied. Titanium aluminide coatings with a regular network of cracks were obtained by electrospark treatment of the Ti6Al4V alloy in an equimolar mixture of titanium and aluminum granules. To fill the lubricant voidnesses in the MoS2 coatings, the hydrothermal synthesis method was used in a solution of thiourea and sodium molybdate at 220 oC. The structure of the coatings was studied by X-ray diffraction analysis, scanning electron microscopy, X-ray microanalysis, and Raman spectroscopy. The wear resistance of the coatings was studied according to the ASTM G99 standard with dry sliding friction using counterbodies in the form of discs made of high-speed steel P6M5 at a speed of 0.47 m/s under a load of 25 N. It was found that intermetallic compounds Ti3Al, TiAl, TiAl3 and TiAl2 were overwhelming. In the structure of Ti – Al coatings, a regular network of cracks with a thickness of 0.77 ± 0.3 μm and a specific area on the coating surface of 2.2 ± 0.35% was established. It was shown that as a result of hydrothermal synthesis, a MoS2 layer is formed on the surface of the samples, consisting of spherical particles with a diameter of 3.09 ± 0.63 μm. Based on the data of energy dispersive spectroscopy (EDS) mapping, it was concluded that cracks in Ti – Al coatings are also filled with MoS2. According to the results of tribological tests, it was found that the hydrothermal deposition of MoS2 on Ti – Al coatings enables to reduce their friction coefficient by 30%, and the reduced wear in dry sliding friction by 2 times. The conducted studies show the promise of hydrothermal deposition of MoS2 on Ti – Al coatings in order to study tribotechnical properties.The study was supported by the Russian Science Foundation (No. 19-73-00031).

Nanostructural glass composite coatings

The results of the study of glass-composite nanostructured self-lubricating coatings are presented. The developed glass composite is an antifriction material with an ultrafine structure. The structural components of these coatings significantly affect the graphitization process and provide an antifriction surface layer of α-graphite. The formation of this layer makes it possible to significantly minimize the contact parameters in the friction region.
 The developed antifriction nanostructured glass-ceramic self-lubricating coatings containing magnesium carbide and structural components that promote surface graphitization do not contain expensive and scarce components, meet environmental safety requirements, and have high performance characteristics. A significant effect of aluminoborosilicate in the form of a glass phase on the tribological properties of coatings is noted. An increase in adhesive strength is achieved by forming a surface layer of glassy sodium silicate. Using X-ray phase analysis, it was found that the intercalating elements in the subsurface zone-graphite system at the initial stage of the process were Mg2+, Al3+, Cu2+ ions, which randomly penetrated into the interlayer space of the graphite matrix. At sliding speeds of more than 3.0 m/s, intercalates of binary molecular compounds of these elements with oxygen were found in the layered system of graphite. Their intercalation is accompanied by a sequence of repetitive stages, which are reversible with a change in tribological parameters and are characterized by a specific transformation of the structure and, above all, by an increase in the distance between layers due to the influence of various types of interlayer defects and the introduction of intercalants.
 The presence of near-surface particles in the graphite layer does not affect the tribotechnical characteristics of the coatings. The developed glass-composite nanostructured self-lubricating coatings have high antifriction characteristics throughout the entire load-speed range

Influence Analysis of the Antifriction Layer Materials and Thickness on the Contact Interaction of Spherical Bearings Elements

Bearings are the supporting elements of bridges. They perceive vertical and horizontal loads from the bridge span. Spherical bearings are one of the construction common types. The material and configuration of the anti-friction layers determine the bearing performance. The paper performed the contact deformation analysis of spherical bearing elements at a nominal vertical load of 1000 kN. The six types of the spherical sliding layer material are considered: ultra-high molecular weight polyethylene (UHMWPE) from three different manufacturers, modified polytetrafluoroethylene (PTFE), and composite materials by PTFE with two different forms of reinforcing bronze inclusions. Young’s modulus, Poisson’s ratio, and strain curve are obtained experimentally for spherical sliding layer materials. Paper considered the influence of the sliding layer material on the contact parameters and deformation characteristics of the structure with a standard interlayer thickness by 4 mm. Research observed significant the composite interlayer deformation and the appearance of “no contact” zones on the mating surfaces. The option of increasing the sliding layer thickness up to 6–8 mm is considered. A decrease is observed in the maximum level of contact parameters by increase of the sliding layer thickness. The influence of the anti-friction layer materials becomes insignificant on the bearing deformation with an increase of the spherical sliding layer thickness.

Detonation Self‐Lubricating Antifriction Glass Composition

Antifriction self‐lubricating glass composite coatings of the Sic‐Ni‐Cu‐Al‐Si‐C type additionally contain an aluminoborosilicate glass phase and structurally free MgC2, which forms α‐graphite during thermolysis, the synergistic effect of which causes modification of the friction surface due to the formation antifriction layer. The influence of the structural components of the coating on their contribution to the antifriction properties is considered. It was clarified that an increase in the adhesive strength of the coatings was achieved by preliminary application of a sublayer of vitreous sodium silicate. The developed coatings showed high performance properties, while the means of minimizing and stabilizing wear characteristics was the presence of a thin‐film antifriction layer based on α‐graphite, which shields unacceptable processes of molecular‐adhesive interaction.

Methods for calculation and experimental evaluation of nucleation and development of the fatigue damages in tin based babbitt and babbitt lining of plain bearings

Fatigue damage to babbitt layers of plain bearings is often manifested during operation. The goal of the study is to develop a model for accumulation of the fatigue damage and destruction of antifriction materials and layers of plain bearings. A generalized fatigue diagram of tin-based babbitts including the main stages of fatigue damage and a diagram of the fatigue damage development in the antifriction layer of plain bearings are presented. The generalized model of V. V. Bolotin for damage accumulation and destruction is modified with regard to antifriction materials containing rather large structural elements. An explicit (direct) modeling of damage processes appeared possible for such materials. The model describes dissipated accumulation of microcracks (interpreted as destruction of the elements of the material structure), initiation and development of a system of short cracks, initiation and development of macro-cracks up to the limit state of the object. The model suggests discretization of the volume into sections with constant levels of complex stress state and discretization of the time axis into the intervals (blocks of loading cycles). The problem of identifying the parameters of a multistage model of the fatigue damage accumulation in the alloy is solved proceeding from the analysis of the results of testing babbitt specimens. We used the simplest optimization procedure, i.e., the method of deformable polyhedron. The parameters of the power function in the dependence of the rate of microdamage accumulation on the level of stresses are obtained. The parameters of the initiation and development of the crack system in the babbitt layer are obtained from the analysis of experimental results of studying steel-babbitt samples. The problem of calculating the durability of antifriction babbitt layers required the development of a new software. The program is examined by comparing calculated and experimental values of the durability of fatigue-tested bearing specimens forced against a rotating shaft by varying cyclic load. The calculated values of the durability match the experimental which confirms the performance of the calculated model.

Liquid-phase hydrothermal deposition of MoS2 into TiAl coatings on Ti6Al4V alloy

Antifriction layers on the Ti6Al4V alloy were obtained by creating a developed structure of lubricant pockets with dry self-lubricating substances. In this work, the structure and tribological behavior of TiAl intermetallic coatings after hydrothermal deposition of MoS 2 were studied. Coatings of titanium aluminides with a regular crack network were obtained by a Ti6Al4V alloy electrospark treatment in an equimolar mixture of titanium and aluminum granules . The etching in HF solutions significantly increases the crack width (from 0.77 to 4.8 μm). The liquid-phase hydrothermal synthesis was used to fill the cracks acting lubricant pockets in the coatings with MoS 2 . It was shown that a molybdenum disulfide layer consisting of spherical particles with a diameter of 3.09 ± 0.63 μm formed on the surface of the samples filling the cracks as a result of hydrothermal synthesis. The results of tribotechnical tests showed that the hydrothermal deposition of MoS 2 on TiAl coatings reduces their friction coefficient to 0.29 and the wear rate by 5.4 times. Cu-plating protects TiAl-layer during etching, increasing the capacity of lubricant pockets. Such treatment reduces wear rate and friction coefficient to 0.17. Lubricant working lifetime was 61 times longer on Cu-plated and etched TiAl coating than on Ti6Al4V polished surface. Studies have shown the promise of hydrothermal deposition of MoS 2 on the Cu-plated and etched TiAl coatings to improve tribological properties of the Ti6Al4V alloy. • TiAl/MoS 2 coating was prepared by ESD, Cu-plating, etching and hydrothermal coat. • The etching by HF acid converts the TiAl coating cracks into lubricant pockets. • The MoS2 presents in etched TiAl coating cracks after hydrothermal treatment. • The etching and MoS 2 deposition reduce COF of the TiAl coating from 0.97 to 0.29. • Cu-plating before etching increase the lubricant lifetime of TiAl/MoS 2 coating.