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ENVIRONMENT SAFETY TECHNOLOGY OF CREATING OF A WEAR-RESISTANT COATING ON ALUMINUM ALLOY SUBSTRATES
Authors: L.V. KOZYREVA., V.V. KOZYREV, A.V. SMIRNOV
Abstract: The results of research work on the creation of a method of applying wear-resistant cobalt-chromium coating on aluminium alloy substrate by thermal decomposition of organometallic compound vapours are presented. It is stated that the method is characterised by sequential application of an adhesive layer of a mixture of nitrosyltricarbonyl cobalt and argon carrier gas and a surface layer of chromium hexacarbonyl at the temperature of thermal decomposition of organometallic compounds. It is noted that metallisation is carried out in a closed cycle, excluding the contact of workers with toxic substances and emissions of pollutants into the atmosphere, thus ensuring the safety of the production process. Coatings with necessary physical and mechanical properties are obtained, which proves the effectiveness of the applied approaches, contributes to the increase of wear resistance of parts and the increase of the service life of machinery.
Keywords: CVD-method, aluminum alloy, wear-resistant cobalt-chromium coating, hardening.
INFLUENCE OF SURFACE WAVINESS ON CHARACTERISTICS OF CONTACT INTERACTION OF MACHINE PARTS
Authors: V.V. IZMAILOV, A.F. GUSEV
Abstract:
The influence of waviness of technical surfaces on the contact interaction of machine parts has been studied. The parameters of roughness and waviness of the surfaces of experimental samples according to GOST R ISO 4287-2014, the mechanical properties of the sample materials and a description of the experimental methodology are given. Theoretical dependences of the contour contact area on the nominal pressure, the parameters of roughness and waviness of the contacting surfaces and the mechanical properties of the materials of the contacting parts are proposed. It has been shown theoretically and experimentally that waviness significantly affects the size of the contact area of machine parts. It is observed that, depending on the magnitude of the nominal contact pressure, the contour area formed by elastic wave deformation ranges from a few units to several tens of per cent of the nominal contact area.
Keywords: contact interaction, roughness, waviness, contour contact area.
POWDER LASER CLADDING OF A WEAR-RESISTANT COMPOSITE COATING
Authors: L.E. AFANASIEVA, K.A. SAKHAROV
Abstract: Metal-ceramic NiCrBSi-WC coating on 40X structural steel has been obtained by laser powder surfacing method. It is shown that cladding of high-alloyed powder mixture with the help of multichannel laser forms practically porous coating and provides metallurgical alloying with the base. It is noted that the fusion line is homogeneous in structure, and it confirms high homogeneity of integral heat input during cladding by this type of laser. It is established that due to high speeds of heating and cooling of the melt during powder laser cladding the dissolution of WC carbides in the melt bath is insignificant. No emission of brittle phase at the carbide-metal matrix interface was detected.
Keywords: microstructure, metal-ceramic coating, laser powder surfacing, multi-channel laser.
INFLUENCE OF DISPENS FILLERS ON FRICTIONAL PROPERTIES OF CERAMIC COATINGS
Authors: A.N. BOLOTOV, V.V. NOVIKOV, O.O. NOVIKOVA
Abstract: Tribotechnical characteristics of an innovative material representing a composite coating with a matrix of aluminium oxide and fillers of nanodispersed magnetite and microdispersed molybdenum disulphide and graphite have been studied. It is established that the minimum values of friction coefficient and wear intensity while maintaining high strength properties of materials are achieved at the concentration of dispersed particles in the electrolyte: for magnetite – not more than 20 g/l; graphite – not more than 40 g/l; molybdenum disulphide – 45 g/l. It is emphasised that the tests showed the stability of the friction coefficient of the investigated coatings during 90 hours. The influence of contact pressure on the intensity of linear wear has been studied. The criterion of transition from elastic contact to plastic contact is proposed. On the basis of it the calculation relation for estimation of transition from stable operation of tribo-conjugation to its catastrophic wear is received.
Keywords: microarc oxidation, antifriction fillers, ceramic coating, friction, wear.
INFLUENCE OF DIAMOND BURNISHING ON THE STRUCTURE AND PROPERTIES OF THE SURFACE OF LASER CUTTING HIGH-ALLOY STEEL
Authors: D.A. BARCHUKOV
Abstract: The results of studies of the microstructure, microhardness, microgeometry of the laser cut surface of deposited high-speed steel grade R9M4K8 after diamond burnishing are presented. It has been shown that the surface roughness of a laser cut is reduced by 3...4 times, which makes it possible to obtain a working surface without subsequent mechanical grinding. It is noted that diamond smoothing leads to microstructure refinement, increase of steel microhardness up to 9 700 ± 130 MPa.
Keywords: laser cutting, steel, diamond burnishing, roughness, microstructure, microhardness.
MEASURING THE POSITIONAL DEVIATION OF HOLES COORDINATED IN THE ANGULAR DIRECTION AND RELATIVE TO THE CENTRAL HOLE OF THE PART
Authors: A.P. ARKHAROV
Abstract: Analysis of the known methods and devices for shaft installation on metal-cutting machines when processing keyways is done. The essence of the developed method for installing a stepped shaft is outlined. The device and operating principle of the designed device with two clamping mechanisms are presented. Comparative analyzes of the developed method and device with similar known solutions are carried out. The development originality and the achieved technical result are reflected in this work.
Keywords: shaft, installation, keyway, positioning, method, accuracy, device, clamping mechanism.
SYNTHESIS OF TECHNOLOGICAL ROUTES FOR MANUFACTURING PARTS IN THE PRODUCTION AND REPAIR OF PEAT MACHINES IN CONDITIONS OF MULTIPLE PRODUCTION
Authors: I.V. GORLOV, E.V. POLETAEVA
Abstract: A new approach is outlined in the production of peat machine parts in a multi-range production environment. It has been established that when synthesizing the technological route for manufacturing peat machine parts in conditions of non-core diversified production, the problem of loading existing flexible production systems (GPS) often arises. It is recommended to ensure the production of scarce parts of peat machines in non-core production due to the rational distribution of technological tasks for each flexible production module. It is indicated that computer-aided process design systems are used to improve the efficiency of technological training, and it is also noted that they do not fully ensure the achievement of a high-quality solution, since a specific GPS may not correspond to the typical approach for the part in question. To solve this problem, it is proposed to analyze the design and technological elements (CTE) of the part and determine possible ways to obtain them, taking into account existing equipment. It is indicated that in order to achieve high efficiency and the necessary product quality in a multi-product production environment with a constantly changing load of a flexible production module, it is necessary to expand the technological capabilities of GPS by using additional technological modules for existing machines responsible for the manufacture of problematic CTE.
Keywords: peat machines, mechanical engineering technology, automation, technological preparation of production, structural model, group technology, flexible production systems.
APPLICATION OF VERTICAL DRAINAGE FOR PREPARATION OF A PEAT SITE PRODUCTION SITE
Authors: O.V. PUKHOVA
Abstract: The questions about the possibility of using vertical forced cluster drainage for additional drainage of a heavily watered production site on the peat area of the ephthrophic type are considered. The least negative impact of drainage on the natural environment, in particular on the regime of adjacent water bodies, during the development of the peat deposit "Ilyinskoye" is revealed. The influence of additional forced drainage (depending on precipitation and volume of pumped water) on indicators of groundwater level changes in wells and canals was studied. The interaction of vertical wells with peat deposit in the process of additional forced drainage at the control site during the season was analysed. It is established that for vertical filtration the peculiarities of the head ephyre depend on the changes of the filtration coefficient in the layers of the deposit. It was revealed that continuous pumping of water from vertical wells led to the formation of a depression funnel with local additional depressions near the wells. The efficiency of using vertical drainage was confirmed when the moisture content of the production layer is lower than normal (up to 73.3 %). It was noted that the deposit thickened unevenly, and the distribution of moisture potentials was non-equilibrium and depended on the distance to the dryers, as well as on the filtration properties of peat and other factors.
Keywords: peat, peat deposit, drainage, vertical drainage, hydrological regime, groundwater level, pressure, filtration coefficient, well debit, vertical filtration.
A CURVED SURFACE SCANNING MATHEMATICAL MODEL
Authors: D.I. KOTLYAR, A.N. LOMANOV
Abstract: The article considers the issue of automating the repair process of gas turbine engine (GTE) blades using a scanning system. The approach to scanning of the part by the vision system installed on the same equipment, on which the cladding repair will be performed later, is proposed. It is noted that the above algorithm is adaptive to the mechanical condition of the equipment. It is indicated that in comparison with the manual method the scanning accuracy is over 0.05 mm (P = 67.56 %) and over 0.1 mm (P = 95.75 %), which is sufficient for further application of the obtained scans in the task of GTE blade repair.
Keywords: computer vision, metal deposition, metal parts repair, GTE blade repair, machine vision system, scanning thin blades.
CHARACTERISTICS OF AUTOMATIC DETECTORS UNOBTRUSIVE DYNAMIC OBJECTS ON LOW-CONTRAST IMAGES GENERATED BY OPTOELECTRONIC DEVICE IN COMPLEX BACKGROUND CONDITIONS
Authors: V.K. KEMAYKIN, A.Yu. KOZLOV, A.A. KHRAMICHEV3
Abstract: The article proposes an automatic adaptive detector that implements the locally most powerful unbiased (LNMN) criterion and its comparison with the detector according to the Neumann-Pearson criterion for extremely difficult observation conditions for optoelectronic devices. The performance characteristics of adaptive detection of low-contrast images of dynamic objects in complex background conditions are constructed. Calculated estimates confirming the superiority of the LNMN rule over the classical Neumann-Pearson rule are obtained.
Keywords: optoelectronic device, dynamic object, image, phono-target frame, detection criteria and characteristics.
DIGITAL TRANSFORMATION OF PEAT INDUSTRY. PART 1. PRINCIPLES OF GEOMODELING OF PEAT DEPOSIT
Authors: T.B. YAKONOVSKAYA,
Abstract: The article describes the methodology of peat deposit geomodeling. The principles of creating and using a digital model of peat deposit are shown. Peat production as an information object is evaluated. The article describes the peculiarities of geoinformation systems application in the conditions of peat extraction enterprises, as well as the sources of initial information required for geomodeling of peat production facilities.
Keywords: peat deposit, modeling, modeling objects, sources of information, modeling principles.
CAE-MODELING OF THE TEMPERATURE FIELDS OF THE NOZZLE OF A SCRAP CUTTER COOLED BY A JET OF CUTTING OXYGEN USING COUPLED CALCULATION
Authors: D.A. ZORENKO
Abstract: The article presents the main results of CAE-modeling of temperature processes occurring in the nozzle of a scrap cutter when cutting scrap with a thickness of more than 800 mm. The temperature distribution in the nozzle body is shown when it is cooled by a jet of cutting oxygen. The features of creating computational models of heat transfer from the scrap surface to the working end of the nozzle are considered, and conjugate calculations of temperature fields in the nozzle body during cold purging with a jet of cutting oxygen of the central channel are carried out.
Keywords: oxygen gas cutting, temperature field, finite element method, computational model, computational aerohydrodynamic, scrap, coupled calculations, coupled heat transfer.