2022 № 97 Різання та інструменти в технологічних системах
Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/65926
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Документ Calculation of shear angle when cutting with a tool of a negative rake angle(Національний технічний університет "Харківський політехнічний інститут", 2022) Manovytskyi, O.; Klymenko, S.; Burykin, V.The article considers the results of the study of the cutting process in order to obtain the calculated dependences of the shear angle oF the physical and mechanical properties of hard-worked iron-carbon steels and alloys in thermobaric conditions of the cutting process and the value of the negative rake angle which is a typical tool for processing with polycrystalline superhard materials (PSHM) cutting tools. When cutting, the formation of chips occurs in the plastic flow of metal in the area of cutting or fracture with the formation and subsequent development of cracks and the subsequent separation of elemental or stepped chips. A well-known chip shaping scheme with one plane shift and the value of the contact area of the front surfaces of the cutting elements with the allowable material to be removed are used to describe the contact phenomena in the chip forming zone and calculate the shear angle in this plane. It is established that the inverse relationship between the shear angle and the negative rake angle of the cutting element indicates that the increase in the negative value of the rake angle leads to a decrease in the shear angle. The specific elongation and shortening of the processed material at the cutting temperature are defined by the authors as the characteristics of shear plasticity and selected for use in the calculation of the values of shear angles during blade processing. As a result of this work, the calculated dependences of the shear angle values on the physical and mechanical properties of heavy duty ferro-carbon steels and alloys in thermobaric conditions of the cutting process and the value of the negative rake angle, which is characteristic of machining with tools of PSHM equipped.Документ Influence of determination accuracy of the build step on the efficiency of adaptive slising group of products for layered manufacturing(Національний технічний університет "Харківський політехнічний інститут", 2022) Garashchenko, Yaroslav; Harashchenko, O.Research results on improving the efficiency of the developed algorithm for adaptive layer-by-layer dissection are presented on the example of 3D models group placed in the workspace of an additive setup. This algorithm for 3D model adaptive cutting allows you to increase the productivity of the process and adjust the accuracy of manufacturing products, taking into account their geometry, by setting a rational value of the variable building step for each individual lowering of the work platform. Building step is calculated taking into account the distribution of the direction of surfaces normal of products group (relative to the construction direction) that fall into the current layer. The developed algorithm provides for some truncation of this distribution, which makes it possible to further increase the building step and, accordingly, reduce the number of layers. Thus, conditions can be created for rational support and given reduction in building time. This achieves a reduction in building time compared to existing strategies for variable dissection. Estimate of efficiency of adaptive layer-by-layer dissection was carried out taking into account the accuracy of determining (setting) building step in relation to 5options for placing 3D models of industrial products in workspace. Comparative analysis of dissection options was performed by the number of layers and assessment of deviations from of surfaces correct shape. Increase in the efficiency of layer-by-layer shaping process with increased accuracy in determining variable step of building a group of complex products placed in workspace of installation has been revealed. This research was developed at the Department of "Integrated Technologies of Mechanical Engineering" named after M. Semko of NTU "KhPI".Документ Fem analysis of the burnishing process of X5CrNi18-10 stainless steel(Національний технічний університет "Харківський політехнічний інститут", 2022) Sztankovics, István; Varga, GyulaThe burnishing process can improve the surface roughness of machined parts, while having an advantageous effect on the properties of the layer below the surface. In this paper the effect of the surface speed, the feed rate and pressing force are analysed with Finite Element Method. The affected width and depth were analysed during one pass of the burnishing tool. We also examined the highest pressure and the stress distribution of the surface layer. The values of the studied parameters were chosen according to the “Design of Experiments” method. Equations determining the studied properties were also given.Документ Investigation on production paramrters of additivelly manufactured ABS polymer gears(Національний технічний університет "Харківський політехнічний інститут", 2022) Mehdiyev, Z.; Felhő, C.; Berkes Maros, M.The amount of wear and the load-bearing capabilities are important factors in the lifespan performance of gears. And those factors can be influenced by different 3D printing parameters in production. The objective of the research work was to analyze the material behaviour of printed Acrylonitrile butadiene styrene (ABS) polymers for gears according to production parameters. Each printed specimen was tested several times and summarised the results by determining the average values. While the wear performance of the samples was highly influenced by the "Layer height" parameter, the load-bearing capacities of the printed samples were highly influenced by the amount of the "Infill pattern" production parameter. Finally, based on the carried out experimental tests, the ideal 3D printing parameters were decided to provide the highest load-bearing capacity and the lowest friction coefficient under compressive forces for 3D printed ABS polymer gears.Документ Analyzing the effect of the tool pass number and the direction of sliding burnishing on surface roughness(Національний технічний університет "Харківський політехнічний інститут", 2022) Nagy, Antal; Varga, GyulaNowadays, the concern of environmental protection is becoming more and more important in production as well. They often contribute to this by reducing or eliminating the amount of coolants and lubricants, or by using alternative machining methods. One of them is burnishing, which makes a positive effect on surface integrity, while reduces the environmental load. In this paper we examined the change in surface roughness achieved by burnishing after turning on a corrosion-resistant steel workpiece, where the number of burnishing passes and burnishing direction were changed. The results showed increased smoothness, bearing capacity and dimensional stability by increasing the number of passes from 1 to 2, however, the 3 times repetition did not show any additional favorable improvement on the surfaces. In case of the forward-backward-forward burnishing directions, further chipping occurred, in other cases the effect of the directions was negligible on the amplitude roughness parameters, but considerable on the parameters characterizing the roughness peak. The greatest improvement was achieved with the backward-forward settings.Документ Surface modification of synthetic grinding powders diamond with heat-resistant oxides and chlorides liquid phase application method(Національний технічний університет "Харківський політехнічний інститут", 2022) Lavrinenko, V.; Poltoratskiy, V.; Bochechka, O.; Solod, V.; Ostroverkh, Ye.; Fedorovich, V.The restrictions to the selection of oxides, which may be interesting in the modification of forging heat-resistant oxides of the surface of diamond grinding powders, are defined. It is shown that the first group of the most efficient applied for modifying the surface of the diamond grinding powders includes the following oxides – B₂O₃, TiO₂, SiO₂ and Al₂O₃. The second group, less effective – ZnO, BaO and CaO. To achieve an additional positive effect from the modification it is possible to consider a double modification of surface of diamond grains with a mixture of oxides of the first group and chloride (СаСl₂, NaCl). The process of grain surface modification of synthetic diamond grinding powders by heat-resistant oxides and chlorides of metals and non-metals by liquid phase application has been studied. The structural characteristics of the external structure have been studied and the quantitative elemental composition of the surface of modified powders has been determined. It is established that to achieve a guaranteed increase in wear resistance of diamond wheels when grinding hard alloys at least 2 times it is recommended to modify the surface of diamond grains with a combination of oxides: B₂O₃ grain surface modification (50 % grain) and Al₂O₃ grain surface modification (50 %).Документ Comparison analysis of material handling solutions of production workplaces(Національний технічний університет "Харківський політехнічний інститут", 2022) Telek, PéterProduction and assembling workplaces can be different in manufacturing and physical environment characterisations, or internal structure, involving the applied material handling solutions, which must be suited to the workplace specifications. The general objective of my research is to develop a model which can help to select the most suitable material handling equipment for production workplaces. The topic presented in this paper deals with the comparison of the different handling solutions. After the overview of the material handling model and the handling equipment selection procedure of production workplaces, a comparison analysis of the applicable handling solutions will be introduced. The last chapter of the paper contains an example for the comparison analysis of a given workplace.Документ Causec of different waves of machined surfaces after up and down end-milling(Національний технічний університет "Харківський політехнічний інститут", 2022) Dyadya, S.; Kozlova, Olena; Karamushka, D.; Kushnir, E.In modern industry, among the methods of surface treatment is widely used end-milling. Under certain conditions of its use there are self-oscillations, which significantly affect the quality of the treated surface. Various techniques are used to study this influence, in particular, the comparison of the basic fragments of the oscillogram obtained by cutting with the treated surface. It is established that it is formed by the first and last wave of self-oscillations during up and down milling, respectively. But depending on the direction of feed step and the height of the waviness on it have different meanings. Therefore, it is important to determine the reasons that lead to this result. This paper considers the features of each direction of supply that affect the formation of the treated surface. When superimposing fragments of the oscillogram obtained by up milling, it is seen that the deviation of the first wave of self-oscillations from the position of elastic equilibrium starts from the point of incision of the cutter in the part. Therefore, the pitch of the wave on the treated surface depends on the feed and the number of cuts required to cut the first protrusion on the cutting surface. The paper presents a formula for determining the length of the base of this speech. When using it, the discrepancy between the calculated wave step on the treated surface and the measured one does not exceed 4%. In the case of down milling, the last section with waviness on the cutting surface, which is cut and affects the shape of the treated surface, has a shorter base length than the opposite. This is the first reason why the pitch of the wave in the down milling is smaller than in the up. Also at formation of wave on the processed surface at down milling the feature in the form of shift on a phase of waves of self oscillations on each following cut is observed. This increases the cutting time and the length of the cutting surface. Each subsequent forming depression is shifted towards the treated surface with a decrease in its deviation from the position of elastic equilibrium. However, the phase shift direction is opposite to the feed direction. This is the second reason why the pitch of the wave on the machined surface after the down milling is less than after the up. The calculation of the step of the wave of the treated surface after the down milling according to the results of the study of fragments of oscillograms shows that the error does not exceed 12% compared to the measured one.Документ Analysis of the Sbi and Svi functional indices in hard machining(Національний технічний університет "Харківський політехнічний інститут", 2022) Molnar, ViktorThe functional requirements of precision machined parts can be expressed among others by topography parameters. In the automotive industry there is an increased need for the application of high-accuracy quantifying parameters. In this study wear resistance and the fluid retention ability-related 3D surface texture parameters are analyzed based on hard turning and grinding experiments. The less frequently applied functional parameters (Sbi and Svi) are compared to the high-accuracy volume parameters (Vmp and Vvv) to obtain information about the reliability of the former ones. It was found that the correlation between the two types of parameters are quite weak.Документ Structure, composition and mechanical properties of multi-layer vacuum-arc nitride coatings(Національний технічний університет "Харківський політехнічний інститут", 2022) Klymenko, S.; Klymenko, S. An.; Manokhin, А.; Stolbovoy, V.; Beresnev, V.; Šiška, F.; Chlup, Z.The conditions of application of multilayer vacuum-arc nitride coatings on a substrate made from polycrystalline cubic boron nitride (PCBN) are considered using the samples of (TiAlCrY)N/ZrN, (TiZr/TiSi)N, (TiAlSiY)N/CrN compositions. A schematic diagram of a vacuum-arc installation for applying similar coatings is presented, and the technological conditions of coating formation are considered. The structure and composition of the coatings were studied during diffractometric studies, and the performance of coated tools was examined when turning hardened steel. A large amount of the droplet phase in the (TiAlCrY)N/ZrN coating was established. The lattice parameters of two nitrides with an fcc crystal lattice were determined: ZrN – 4.590 Å, TiAlCrYN – 4.203 Å. CSR (coherent scattering region) of the ZrN phase is 5.4 nm at the microstrain level ε = 4.79·10¯³. High homogeneity and low defects in the thickness of the (TiZr)N/(TiSi)N coating were established – the amount of droplet phase is insignificant. The CSR of the coating is 24.2 nm at the level of microstrain ε = 5.76·10¯³, and the predominant texture orientation is (111). A small amount of the droplet phase was found in the (TiAlCrY)N/CrN coating. Both coating layers are characterized by the formation of phases with a cubic (fcc) crystal lattice, and a strong (111) texture occurs. The crystallographic planes (111) of the phase grains are mainly oriented parallel to the coating interface. The size of the CSR is 14.6 nm. It is shown that multilayer vacuum-arc coatings lead to an increase in the tool life of PCBN cutting tools by reducing the effect of adhesive sticking of the processed material and reducing the intensity of chemical interaction in the cutting zone.