The paper presents results of research for influence of plasma jet parameters (current, spraying distance, plasmasupporting nitrogen gas consumption), fractional composition of an initial powder and cooling degree by compressed air on characteristics of anti-meteorite coatings, subsequent processing modes by pulsed plasma. Properties of the obtained coatings and results of ballistic tests have been given in the paper. The proposed methodology has been based on complex metallographic, X-ray diffraction and electron microscopic investigations of anti-meteorite aluminum oxide coating. Optimization of air plasma spraying parameters for NiAl and Al₂O₃ materials has been carried out in the paper. The spraying parameters optimization has been executed on the basis of obtaining maximum materials utilization factor. Surface treatment of model screen elements with a double-layer composite coating (adhesive metal NiAl layer and hard ceramic oxide Al₂O₃ layer) has been fulfilled while using compression plasma stream. Nitrogen has been used as working gas. Composite hard ceramic oxide Al₂O₃ coating is represented by porous structure consisting of 10–15 µm-size fused Al₂O₃ particles. Metallic inclusions formed due to erosion of plasmatron electrodes have been observed in the space between the particles. Surface of bilayer composite coatings has been processed by a compression plasma stream and due to nonsteady processes of melting and recrystallization high strength polycrystalline layer has been formed on their surface. In this context, those areas of the polycrystalline layer which had metal inclusions have appeared to be painted in various colors depending on chemical composition of the inclusions.

. Creating a functionally oriented, including nanostructured, anti-friction materials and coatings with qualitatively new complex of service properties is an important scientific and practical problem. In particular, for the cable industry it is urgent task of ensuring the high performance properties of fast deteriorating stretching and supporting rollers. Working surfaces of these parts operate under practically dry friction conditions with constantly updated material of stretching wire. Plasma spraying is one of the widely used methods of surface engineering to create wear resistant coatings and which is characterized with process flexibility and the ability to create coatings using various materials and alloys including composite ones. The installation UPU-3D with the PP-25 plasma torch was used for plasma spraying. The thickness of the sprayed layer was 0.8–1.1 mm. As a material for the deposition of composite coatings a powder mixture of self-fluxing nickel alloy PG-HN80SR4 (system Ni–Fe–Cr–Si–B–C) and a neutral oxide ceramics Al₂O₃ was used. The amount of ceramics varied from 15 to 33 %. This ceramic oxide was selected due to the desire to reduce coatings’ costs while providing high durability. Carried out phase and microstructural studies have shown when ceramics was added in an amount more than 20 % a formation of conglomerates formed by not melted alumina particles often was observed. These conglomerates serve as crack formation centers in the coating. The phase composition of the coatings practically does not depend on the content of ceramics compounds. Tribological tests have shown that the best results were obtained when the content of the oxide ceramic in the coating was in the range from 15 to 20 %.

Pollution of an atmosphere due to hazardous substances emissions deteriorates ecological environment in the world. Exhaust gases of diesel engines are considered as one of the main environmental pollutants. At the moment it is not possible to determine rate and limits of threshold level of air pollution which do not affect human health. The paper considers current issues pertaining to regulation and control over dispersed particles. The most convenient measuring methods for investigations are those which provide the opportunity to obtain immediate results. However, from the legislative point of view, a gravimetric investigation method is a legitimate one which requires compliance with certain procedures of adjustments and calculations. The method presupposes availability of complicated system for sample dilution and its adjustment must include temperature and kinetic parameters of the measured flow. In order to ensure measuring accuracy and results reproducibility filter loading should be in a regulated range and dilution parameters should be chosen according to not only engine type but also according to its emissions rate. Methods for evaluation of a hot exhaust gas sample is characterized by higher response and the results correlate with indices of combustion efficiency. However, such approach does not account for a number of processes that take place during gas cooling in the environment. Therefore, in this case, measuring results are to be evaluated within certain boundary conditions with respect to the object of investigations. Difficulty in achievement of modern ecologocal standards is substantiated by complicated fractional composition and multiple stage process in formation of hazardous components. The paper presents calculated dependences between particles and smokiness and contains a comparative analysis. Methods for measurement and investigations of dispersed particles have analyzed on the basis of the results obtainesd during engine tests at various values of fuel supply parameters (injection pressure and timing advance angle of fuel injection).

The paper reveals results of investigations on mass transfer kinetics and dynamics of coating formation while using integral electrospark alloying method with additional ultrasonic exposure at different stages of formation. Nowadays, a classical method for electrospark alloying with hard-alloy anodes and impulse AC voltage frequency on the vibration exciter coil from 20 to 1600 Hz has been mainly used for application of protective and strengthening coatings within permissible thickness and characteristics. The key aspect of ultrasonic exposure application (frequency 22–44 kHz) during electrospark alloying is the possibility to increase further thickness of coatings to be formed even after reaching a brittle fracture threshold of the coating material. Methodology of the executed research activity has been based on integrated studies (gravimetric, metallographic, X-ray diffraction and electron microscopic) of coatings which are to be formed through compositions produced while using method of high-energy hot compaction and a “refractory carbide (WC) and a binding material“ system in the form of alloy based on nickel from the series of “colmonoy” Ni – Ni3B system which is alloyed with additions of copper and silicon. The initial surface treatment within ultrasonic frequency range (22–44 kHz) contributes to a noticeable increase in the mass transfer rate, which is primarily determined by chemical composition and thermodynamic stability of anodes. It is due to surface activation in the process of its preliminary deformation at ultrasonic frequency which creates additional conditions for striking of a spark.The final ultrasonic treatment improves coating quality due to its additional forging that leads to an increase of its structure homogeneity and density.

The paper contains an analysis of dimple geometric parameters obtained on wire surface during its in its electrical discharge machining. A photography and description of one of the dimples has been given in the paper. The paper has analyzed a cross-sectional shape of the obtained dimple with due account of the solidified metal flows formed along its edges. The flows in a first approximation can be considered as elements of a cutting wedge. According to cutting theory provisions the paper considers solidified metal flow shapes in a longitudinal section and indicates angles which have been formed by the flows, working planes and edges which can be involved in the cutting process. It has been shown that cutting elements on the dimple surface are arranged symmetrically that makes it possible to carry out cutting process while moving a tool in both directions of reciprocating motion. Parameters of cutting surface influencing on cutting process execution have been specified in the paper. It has been demonstrated that due to changes in energy of electric discharge through voltage or capacity of a power supply storage capacitor it is possible purposefully to influence on the shape and size of metal flows and, respectively, on values of cutting wedge parameters that characterize a tool cutting ability. A conclusion has been made about possibility to obtain the most advantageous values of these parameters while optimizing modes of wire electrical discharge machining.

The paper considers a current scientific and technical problem pertaining to creation of multi-bridge wheeled chassis for highly efficient modular sugar beet harvesters of large cargo capacity and, in particular, to selection of main parameters of chassis and wheeled drive. Such machines are designed for operation under complicated soil and climatic conditions during sugar beet harvesting. Methodological rules and regulations have been developed for solution of problems pertaining to scientifically sunstantiated selection of a manufactured or developed wheeled chassis model, building-block parameters of a working device and a chassis, rational control algorithm of the unit running system while using a specified (domestic or foreign) semi-mounted equipment for beet harvesting. While solving the problem theoretical provisions for wheeled vehicles regarding specific features of a wheeled chassis for modular sugar beet harvesters with extensive mechanical or hydrostatic wheel drive of a multi-bridge propulsion system have been developed in the paper. Calculated and theoretical expressions for determination of main parameters for a wheeled chassis have been obtained and they include physical quantities of operational conditions that explicitly determine its working process. Such approach has made it possible to realize the obtained expressions as a software application which is suitable for analysis of main parameters in respect of the investigated harvester chassis and rational parameters of a branch wheel drive and also for a complete set of tires in the case when a sugar beet harvester is designed on the basis of wheeled chassis according to the selected scheme. Investigations have theoretical significance and represent practical interest for development spesialists of new modular multi-bridge sugar beet harvesters.

Electric conductivity of vapor-gas envelope in electro-impulse polishing mode is closely connected with mechanisms of physical and chemical processes occurring on an anode surface and in pre-anode area of electrolyte, metal removing, smoothing-out of surface profile irregularities and technological regimes influencing on productivity and processing accuracy. The paper presents experimentally substantiated conceptual model of a mechanism for electric conductivity of vapor-gas envelope. According to the model an electric current passing in the envelope and having quasi-constant and high-frequency components is provided by ionic conductivity in electrolyte envelope-enclosing bridges and ionic conductivity in gas envelope phase. It has been shown that quasi-constant of the current component represents a composition of electric current consisting of overlapping time current impulses from electrolyte bridges that enclose the envelope with frequency of 0.01−0.90 kHz and current in a gas phase of the envelope. High-frequency current component is pre-conditioned by ionic conductivity in bridges that commutate the envelope with frequency of 2.5 MHz. The paper theoretically substantiates excessive electrical conductivity of electrolyte in the electrolyte bridges. It has been demonstrated that formation of vapor-gas envelope and its renovation are connected with thermal burst mechanism for destruction of electrolyte bridges. Envelope vibration and hydrodynamic flows within the electrolyte occur due to impulse wave impact on electrolyte layer which is on the border of the envelope. The waves are caused by burtsts of electrolyte bridges and cavitation bubble collapse in pre-anode electrolyte area.

The paper considers problems pertaining to higher durability and reliability of a cutting tool for cutting gastronomic products while using laser processing that leads to resistance increase of material operating surfaces against impact forces. Influence of laser fusion with additional doping on structure, microhardness, wear resistance for adhesive coatings of Fe–B–Cr–Si system has been studied in the paper. In order to solve a problem for selection of optimal qualitative and subsequently quantitative composition of a multi-component coating a mathematical modeling method using Scheffe’s simplex lattices has been used in the paper. Similar tendency for measuring micro-structure of all adhesive coatings fused by laser beams has been established in the paper. Increase in beam speed has caused the following microstructure changes: cast equilibrium, dendrite, supersaturated boride, carbide and boride. Response surface models have been found and they provide the possibility to assess influence quantity of laser processing parameters on microhardness of adhesive coatings obtained by laser doping and intensity of their wear under various conditions for all investigated compositions.It has been ascertained that there is no strict correlation between hardness and intensity of coating wear after laser doping used for adhesive coatings. This testifies to the fact that hardening has taken place not only due to an increase of carbide-boride phase, but also due to matrix hardening.In addition, a regression model for coating composition effect on tribological characteristics of the adhesive coatings has revealed that an optimal composition of a multicomponent coating ensuring maximum wear resistance of coatings constitutes B4C is 2/3 and 1/3 TaB. It has been determined that hardening of the adhesive coating after laser doping while using multicomponent coating occurs not only due to increase of carbide-boridnoy phase, but also due to matrix hardening.

Performance tuning improvement of modern diesel engines exerts an influence on technical and economic, ecological and resource indices of an internal combustion engine (ICE). In its turn, that requires a complex estimation and improvement of engine indices. As is known, working process and thermal intensity of combustion chamber parts are interconnected between themselves. Changes in design, operating and adjustment parameters of systems and structural elements of internal combustion engines that enable air-fuel mixing and combustions processes stressed state of combustion chamber parts. Joint estimation of operating cycle parameters and strength indices of ICE parts makes it possible to solve a number of problems originating in the process of designing new engine models and further development of the existing ones. The paper provides results of comparative estimation on heat-stressed state of a cylinder head for a high-speed diesel engine Д21A (2Ч10,5/12) while operating a rated power mode. In order to simulate and specify a heat-stressed state for description of boundary heat conductivity conditions the following adjoint “gas – wall” problems have been solved: the first one – for combustion chamber of a diesel engine (an internal problem) – simulation of a working cycle for a diesel engine; the second one – for cooling edges while blowing over them by air flow (an external problem). Calculations have been made in three-dimensional non-stationary presentation within the Cartesian coordinates. In order to simulate a working cycle of the diesel engine a computational grid describing combustion chamber configuration, inlet and outlet channels has been used in the paper. Solution of the external problem for cooling edge surface in case of blowing over them by air flow has permitted to specify temperatures and heat-transfer coefficient and later to improve an accuracy while estimating level of temperatures and stresses of the cylinder head.

The paper considers new methodologies pertaining to on-board diagnosis of wear-out rate for friction linings of a clutch driven disk and friction discs of a hydraulic press clutch of transmission gear boxes which are based on physical process that uses friction work as an integrated indicator. A new methodology in determination of life-span rate for engine oil has been developed in the paper. The paper presents block schematic diagrams for on-board monitoring of technical state for power units of wheeled and tracked vehicles. Usage of friction work as an integrated indicator for determination of wear-out rate for friction linings of clutch driven disk and friction discs of a haydraulic press clutch makes it possible timely at any operational period of wheeled and tracked vehicles to determine their residual operation life and forecast their replacement.While taking volume of the used fuel for determination of engine oil life-span rate it permits quickly and effectively at any operational period of wheeled and tracked vehicles to determine residual useful life of the engine oil and also forecast its replacement.

The paper studies regularities and mechanisms of structure and phase formation in the surface layers of magnesium alloys when they are processed by method of micro-arc oxidation [MAO]. It has been determined that the same specific features of structure formation, namely: existence of a thin dense inner sublayer and a thicker outer sublayer with developed porosity are common for all types of coatings on the surface of magnesium and aluminum alloys. Such structural state of a protective coating can not be considered as a guaranteed protection against operational impacts, taking into account the fields of their primary application that is aviation construction, automotive construction, instrumentation, building construction, etc. The paper has analyzed the effect of alkaline electrolytes with varying chemical composition due to additions of sodium fluoride or potassium on the structure and properties of these alloys as well as on the level of basic performance characteristics of the layers formed in such electrolytes. On the basis of the analysis a conclusion has been made that it is possible to extend their life-span under operational conditions. It has been revealed that the existing techniques and methods for process control of MAO aluminum and magnesium alloys, particularly processing modes and technological equipment capacity determine a nature of structure formation and changes in a phase composition of the formed coatings.

Investment volume is considered as an important factor in regional development under current conditions. Logistical infrastructure which ensures a complex transport, distributive, information and other services exerts a significant influence on regional investment attractiveness. Lack of clear vision on development and execution of development strategy for logistics infrastructure from the side of regional authorities results in unwillingness of large federal and transnational companies to provide investments in infrastructure projects. Network of automotive transport terminals is one of the main elements in logistics infrastructure. The network allows to optimize a flow of material goods from the point of their origin to the point of their consumption with the lowest possible costs and the required level of service. Automobile transport is one of the main objects of transport infrastructure and it is characterized by rather high flexibility in comparison with other types of transport facilities that preconditions its widespread application. Network of automobile fleets (terminals) has been formed for redistribution of goods traffic within the concerned regions. The purpose of the present research is to develop a mathematical model for formation of transport infrastructure on the territory of regions. The paper proposes an approach for formation of automobile fleet (terminal) network on the territory of a large region with due account of the established network of distribution and sorting-out warehouse facilities. A model has been developed for solving the problem pertaining to minimization of aggregate costs related to maintenance of automobile fleets, delivery of goods to and from distribution and sorting-out warehouse facilities to consumers, ferry of empty trucks and goods handling. The model makes it possible to determine optimal number and location area of automobile fleets (terminals) while accounting for their possible locations, capacity and limitations on type and number of transport facilities.