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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 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 The effect of burnishing process on skewness and kurtosis of the scale limited surface(Національний технічний університет "Харківський політехнічний інститут", 2022) Ferencsik, Viktoria; Varga, GyulaIn this paper roughness examination and analysis on burnished low alloyed aluminium surfaces are reported, highlighting 2 parameters from the vertical deviations of the roughness profile from the mean line. From the input parameters of the burnishing process, the effect of burnishing force, feed rate, speed and number of passes are investigated. Measurements of the surface topography – before and after burnishing – are conducted on an Altisurf 520 3D measuring device. The generated and calculated values of the machined surface roughness are analysed in detail with the drawing of the conclusions as well.Документ Experimental examination of surface micro-hardness improvement ratio in burnishing of external cylindrical workpieces(Національний технічний університет "Харківський політехнічний інститут", 2020) Varga, Gyula; Ferencsik, ViktoriaThis paper deals with the experimental examination of surface micro-hardness improvement ratio in burnishing of external cylindrical workpieces. The material of the examined workpiece was AISI 304 austenitic stainless steel. In our experiments, we investigated the sliding frictional burnishing of an outer cylindrical surface when the burnishing tool had a diamond material-grade spherical tip. Using the full factorial experimental design technique, we aimed to determine how the changes in burnishing parameters, i.e., burnishing speed, burnishing feed, and burnishing force effect on the changes of surface micro-hardness and surface micro-hardness improvement ratio. Based on examinations, the best burnishing parameter combination could be selected.Документ Investigation of shape correctness of diamond burnished low alloyed aluminium components(Національний технічний університет "Харківський політехнічний інститут", 2020) Ferencsik, Viktoria; Varga, GyulaConventional machining methods such as turning or milling can cause surface irregularities, defects such as tool traces and scratches, resulting in energy dissipation (friction) and surface damage (wear). In contrast, the environmentally friendly chipless burnishing process clearly improves the integrity of the machined surface and largely considered in industrial cases in order to restructure surface characteristics. In this paper influence of different burnishing parameters, such as burnishing speed (v), feed rate (f) and burnishing force (F) are examined. Based on theoretical considerations, we use full factorial experimental design method to determine the optimal combination level of the different parameters in the given interval. The measurement of the shape correctness was executed with Taylor Hobson Talyrond 365 measuring equipment at the Institute of Manufacturing Science.Документ Examination of the change in surface roughness of burnished low alloyed aluminium external cylindrical pieces(Національний технічний університет "Харківський політехнічний інститут", 2019) Ferencsik, Viktoria; Varga, GyulaThe life and reliability of machine components or elements are affected greatly by the surface integrity. Machined surfaces by conventional processes such as turning and milling have inherent irregularities and defects like tool marks and scratches that cause energy dissipation (friction) and surface damage (wear). Ball burnishing has proved to be a highly effective mechanical finishing process of industrial workpieces because of the excellent surface roughness and fatigue performance that induces in treated components. This paper focuses on the examination of the influence of different burnishing parameters, such as number of passes (i), feed rate (f) and burnishing force (F). For plan and execute the experiments we use full factorial experimental design method by which empirical formulas can be created easily. The measurement of the surface roughness was executed with Altisurf 520 3D measuring equipment at the Institute of Manufacturing Science. The measured results were evaluated by the comparison of a special correlation formula to determine the optimal combination level of the different parameters in the given interval.Документ Examination of 3D surface topography of diamond burnished C45 workpieces(Національний технічний університет "Харківський політехнічний інститут", 2019) Ferencsik, Viktoria; Varga, GyulaNowadays cold working operations like rolling, burnishing are important finishing methods. In this paper the diamond burnishing of external cylindrical surfaces are studied. The principle of this process is that a pressing tool, which goes along the surface of the workpiece with linear motion having given parameters (e.g. feed) while the workpiece is rotating. Using of diamond burnishing has many preferences: surface roughness of the workpiece is improving, hardness of the surface is increasing while it’s micro-structure is also improving. Fatigue strength is increasing significantly due to the compressive residual stress in the subsurface area causing by burnishing. The aim of this study was to examine the influence of different burnishing parameters, such as burnishing speed, feed and force with the using of two different kinematic viscosity oil. For plan and execute the experiments we used the Taguchy type full factorial experimental design method by which empirical formulas can be created easily. The measurement of the surface roughness was executed with Altisurf 520 3D measuring equipment at the Institute of Manufacturing Science. The measured results were evaluated by the comparison of a special correlation formula to determine the optimal combination level of the different parameters in the given interval.Документ Analysis of surface microhardness on diamond burnished cylindrical components(Національний технічний університет "Харківський політехнічний інститут", 2019) Viktoria, Ferencsik; Varga, GyulaCold-plastic forming technologies are one of the most dynamically developing technological processes in these days The main purpose of modern plastic forming is to achieve the shape and size of the designed component by providing minimum environmental loads, while ensuring th e proper values of strength and deformation characteristics.These methods include surface strengthening processes, characterized by the introduction of cold forming hardening and residual compressive stress [1]. In this paper, we study the main types of surface consolidation in detail to burnishingof outer cylindrical surfaces.The application of burnishing results in cost reduction in several aspects: cheaper, lower alloyed, lower rigid structural materials can be used as raw materials, abandoned grinding a nd other fine surface machining, can be replaced by heat treatment operations. In our investigation we used polycrystalline diamond tool with spherical machining surface on C60 hardened steel examining the changing of surface micro-hardness caused by different burnishing parameters.Документ Examination of 2D and 3D surface roughness parameters of face milled aluminium surfaces(НТУ "ХПІ", 2018) Kundrák, János; Varga, Gyula; Nagy, Antal; Makkai, TamásMaterial removal with a rotating cutting tool has a series of special characteristics due to the movement relations. For face milling, looped cycloids occur, which also affects the roughness characteristics of the machined surface. This article analyses how the values of 2D and 3D roughness parameters change in symmetrical milling of flat surfaces of aluminium parts in planes parallel to the feed direction.Документ Examination of residual stresses on diamond burnished cylindrical surfaces(НТУ "ХПИ", 2017) Varga, Gyula; Ferencsik, ViktoriaCold plastic finish manufacturing methods such as surface rolling, burnishing and surface hardening with shot peening play important role in the lifetime increasing manufacturing as compressive residual stress remains in near surface layers of the workpiece. This paper deals with examination of changing of residual stress caused by burnishing using diamond tipped tools. The diamond burnishing executed on outer cylindrical surfaces is a finishing manufacturing operation which results high accuracy and fine surface texture. The aim of the examinations was to determine how the burnishing speed, feed rate and burnishing force has affect on the residual stresses in case of diamond burnishing of low alloyed aluminium shafts. The Taguchi type Factorial experiment design was used for planning of experiments. The measurement of residual stresses was performed by an X-ray diffraction method. The evaluation of measured results was done by a specially specified ratio to determine the parameter set which results the best residual stress values in between the given range of technological parameters.