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Metalworking № 1 (145)/2025 |
Material cutting
Processing of high-hard deposits with prefabricated end mills Abstract. The growing demands on the materials of machine parts have led to the creation of materials with a sharp gradient of properties, namely, high-hard surfacing (HRC 65 and more) on a material with normal hardness. High-hardness surfacing must be mechanically processed to the desired part size. The use of grinding is usually excluded. The article presents the results of application for the treatment of surfacing with prefabricated end mills with replaceable carbide plates with different coatings. Keywords: milling of high-hardness surfacing, cutting mode parameters, tool life period
The study of the formation of the surface relief of polymers with a metal filler in the process of abrasive treatment Abstract. The features of the formation of surface roughness of polymers with a metal filler in the process of abrasive treatment with a flexible brush tool are studied. The novelty of the work: the reasons for the low roughness of polymers with a metal filler are revealed. An assessment of the effectiveness of the method of abrasive machining of parts using a flexible tool and cooling with an air-emulsion mixture was carried out. Keywords: additive technologies, abrasive treatment, roughness, moisture absorption, metalfilled Plastics Le Tri Vinh, V. P. Koltsov, V. M. Svinin3 D. A. Starodubtseva Surface roughness of aluminium alloy part during machine grinding with a petal wheel The aim is to study the surface roughness of a part made of aluminum alloy B95T1 when grinding with a flap wheel under processing modes used in production in the manufacture of panels and aircraft skinings. Grinding of a sample of a plate made of aluminum alloy B95T1 with a cylindrical abrasive flap wheel with a diameter of 350 mm and a width of 100 mm with a grain size of P60 was carried out on a laboratory grinding unit designed and manufactured in INRTU in combination with a 1K62 turning and screw cutting machine. The study was conducted using a multifactorial experiment with three variables at two levels of variation. The levels of variation are related to the processing modes, including the speed of rotation of the flap wheel, the feed of the workpiece and the precipitation of the petals in the contact zone with the treated surface. Based on the results of the experiment, a mathematical model of surface roughness was constructed in the form of an arithmetic mean deviation of the profile Ra of the surface of the part in the opposite direction of grinding with a flap wheel [16], depending on the processing modes with a confidence level of 0.95. It was found that regardless of the parameters of the grinding mode, the roughness of the treated surface, Ra, does not exceed 2.03 microns. At the same time, the roughness of the treated surface is directly proportional to the value of the rotation speed of the flap wheel and the value of the precipitation of the petals. The feed of the workpiece has practically no effect on the roughness of the treated surface, or it has little effect. The obtained mathematical model of the roughness of the treated surface of a part made of aluminum alloy B95T1, when counter- grinding with a flap wheel, allows you to assign the necessary grinding mode according to the required roughness of the treated surface. Keywords: grinding plant, grinding with a flap wheel, B95T1, processing modes, roughness of grinding, mathematical model
Study of the process of flat grinding of fragile and hard materials with a free abrasive Abstract. The proposed complex mathematical model of flat grinding with a loose abrasive allows us to study the movement of abrasive grains in a compacted layer when grinding plates of brittle and hard materials, as well as to study the factors that influence the process of flat grinding with a loose abrasive: the force of pressing the treated surface to the grinder; angular speeds of rotation of the grinder and mandrel; concentration, average size and fractional composition of abrasive grains and other factors. According to the known parameters of the law of distribution of grains of a loose abrasive by size, it is possible to obtain the distribution of abrasive grains by the height of the compacted layer and by the radius of the grinder, which allows us to predict the share of participation in the grinding process of grains of different sizes and thus optimize the composition and consumption of the abrasive suspension to achieve the required quality and productivity of the flat grinding process. Keywords: surface grinding, free abrasive, abrasive suspension, grinder, mandrel, mathematical model
New materials and technology
The influence of the angle of inclination of the main cutting edge on the shape and direction of movement of the spiral-shaped drain chips Abstract. The results of the study of the influence of the angle of inclination of the main cutting edge on the shape and direction of movement of the spiral-shaped drain chips are presented. A calculated expression is obtained that determines the critical lкр value, at which there is a change in the direction of movement of the chip spiral. On the basis of computer modeling data, the dependences of lкр on the technological conditions of processing are constructed. Keywords: cutting of materials, drain chip formation, angle of inclination of the cutting edge, direction of movement of spiral chips
Development of technology for manufacturing process equipment (pressure chambers) for testing the effects of rapid pressure changes (depressurization) Abstract. This article consider the technology of manufacturing the design of technological equipment (pressure chamber) and the method of testing for the effect of rapid pressure change (depressurization). Keywords: tests, airborne electronics, depressurization, rapid pressure change, pressure chamber, technological equipment, aircraft, external influencing factors
Investigation of the finishing threaded surfaces method using magnetic abrasive polishing processes Abstract. The article examines the features of magnetic abrasive processing of a complex threaded outer and inner surface, for processing the latter, an auxiliary processing tool was used to create a closed magnetic field circuit. The study considers the analysis of the magnetic field distribution and the magnetic flux density, as well as the numerical characteristics of the magnetic abrasive treatment process and the sample working movements affecting them. Keywords: magnetic abrasive finishing, magnetic abrasive tool, roughness of the threaded surface
Organization and management of production
The concept of „risk resource“ in the risk management model of diversification of shipbuilding enterprises of the defense industry Abstract. Today, enterprises of the military-industrial complex are facing a significant challenge — the diversification of production. Entering the market for civilian products requires not only internal changes within the industry, but also adaptation to new external conditions in order to remain competitive. This presents numerous risks that the companies in the military-industrial sector have not previously encountered, and therefore the need to identify and assess these risks over a longer planning horizon. The aim of this study is to develop a risk management strategy when making strategic decisions regarding production development, including diversification. As a result, we propose a conceptual model for risk management in production diversification, based on the „risk—resource“ approach for design bureaus that are transitioning to civilian product production. Keywords: risk management, concept of „risk resource“, diversification of production, strategic decision, shipbuilding industry |