Gyula Varga | University of Miskolc (original) (raw)

Papers by Gyula Varga

Rad prikazuje tehnologiju izrade trakastog transportera (materijala AISI 304L) od modeliranja dij... more Rad prikazuje tehnologiju izrade trakastog transportera (materijala AISI 304L) od modeliranja dijelova uz pomoć računala, sklapanja svih dijelova transportera u virtualni sklop i izradu dijelova transportera primjenom CAD-CAM povezivanja. Proizvodnja korištenjem CAD-CAM pristupa se može optimizirati i lako kontrolirati, iz čega proizlazi brža, kvalitetnija i efikasnija proizvodnja.

Lecture notes in mechanical engineering, Oct 20, 2017

In the paper, the experimental results of the study on the dynamic characteristics of the air gau... more In the paper, the experimental results of the study on the dynamic characteristics of the air gauges are presented. Dynamical properties of the air gauge are dependent mainly on the pressure transducer type and also on the geometry of its flow-through elements. The present investigations focused on the diameter of the inlet nozzle and its impact on the time constant and the frequency at which the dynamic error would not exceed 5%. It was proved that in the most common configurations of the air gauges, those two parameters may vary up to 100%, and the dynamics of the air gauges worsened with smaller inlet nozzles. The results are of high practical importance in industrial measurement systems where the air gauges are applied, because the multiplication of the air gauge is typically set by the adjustment or replacement of the inlet nozzle.

Multidiszciplináris tudományok, 2021

One of the defining global issues today is to reduce the load on the environment. Thus, in this p... more One of the defining global issues today is to reduce the load on the environment. Thus, in this paper, the effect, and consequences of the abandonment of cooling and lubrication were investigated when turning of non-alloyed steel. The 2D and 3D surface roughness parameters, cylindricity deviations and circularity errors were examined at different feeds and cutting speeds. The experiments were performed, using the full factorial experimental design method. It was found that with dry machining, the average roughness is slightly higher with increasing productivity, however, at lower feed and cutting speeds, the surface has better wear resistance and lubricant retention, and cylindricity deviation can be minimized.

Department of Production Engineering at College of Nyiregyhaza and Department of Production Engin... more Department of Production Engineering at College of Nyiregyhaza and Department of Production Engineering at University of Miskolc cooperates in research of environmentally conscious machining by experimental and simulation methods. In this paper we develop previous modelling results. The aim is quasi-static investigation of the mechanical interaction between the drilling tool and the workpiece. The phenomenon is simulated as contact problem. Forces and torques applied in the simulation comes from experiments. This study gives insight to the mechanical interaction during the machining, and prepares further dynamical investigations.

Proceedings of the Thirty-First International Matador Conference, 1995

The operational features (efficiency, sound pressure, transmissible power, etc.) of worm driving ... more The operational features (efficiency, sound pressure, transmissible power, etc.) of worm driving pairs are basically determined by the oil film formed between the mating surfaces. The design parameters and technological parameters play the main role in the favourable formation of oil film. During design those geometrical parameters, which make possible the formation of appropriate oil film and optimum bearing pattern can be determined. With the help of our mathematical model the optimal design of any cylindrical or conical helicoidal surface can be accomplished. The finishing manufacturing operation of worms can be performed by the use of continuons grinding wheel truing equipment. The basis of geometrical dimensioning of tools necessary for production of worm gears will be shown. The optimal bearing pattern can be adjusted during the assembling of already produced elements of worm driving pairs.

IOP Conference Series: Materials Science and Engineering, 2018

Increasing the cutting speed and/or the feed rate is often chosen to increase the efficiency of t... more Increasing the cutting speed and/or the feed rate is often chosen to increase the efficiency of the material removal. Of course, there are limits to the selection of specific values in both cases, such as, the rigidity of the machining system, the loadability and lifetime of the cutting edges, the prescribed roughness values of the surfaces, etc. When increasing the feedrate in face milling, the conditions of the chip removal change considerably, because at low feed values, the material forming effect of the side edge (i.e. the edge on the lateral surface of the tool) is the most determinative and the chip deforms perpendicular to it, while increasing the feed gradually moves the determinative part of the chip removal to the edge which lies perpendicular to the tool axis. Therefore, both of the two edges have a distinct role in chip removal due to both their position and geometry. The two edges are located on one cutting insert; therefore, their geometry needs to be examined individually and collectively in the search for the most suitable for effective chip removal. The study investigates how the different tool geometrical characteristics affect the roughness parameters of surfaces in normal and in highfeed face milling.

Machines

Additively manufactured metallic parts usually need postprocessing in order to achieve required s... more Additively manufactured metallic parts usually need postprocessing in order to achieve required shape accuracy. Cylindrical test specimens were produced by selective laser melting from Ti6Al4V powder material with different processing parameters. The aim of postprocessing was modification of shape accuracy. Sliding friction diamond burnishing was applied as the postprocessing method. A five-factor, two-level full factorial design of experiment was implemented with factors being infill laser power, infill laser scan speed, burnishing speed, feed and force. Improvement ratios of two roundness parameters were defined, calculated from experimental data, and studied by main effect and interaction analysis. It has been demonstrated that burnishing feed has the largest main effect to improvement in roundness total and cylindricity. Additionally, parameters of both selective laser melting and diamond burnishing appear in three largest interaction terms. Empirical functions were fit to measu...

Machines

This study describes the determination and optimization of burnishing process parameters and thei... more This study describes the determination and optimization of burnishing process parameters and their effects on surface roughness of EN AW-2011 aluminium alloy workpieces. The process has a low environmental load and the chip-free burnishing process improves the integrity of the machined surface, but to achieve this, the different burnishing parameters, for example, burnishing force, feed rate, speed and number of passes, must be properly defined according to the material of the workpiece. In our research, a full factorial experimental design method is used to plan and carry out the experiments and to determine the most appropriate parameter range for this material quality.

Machines

Selective laser melting is a frequently used, powder bed fusion additive manufacturing technology... more Selective laser melting is a frequently used, powder bed fusion additive manufacturing technology for producing metallic parts. However, appropriate surface quality cannot be achieved, so post-processing is often necessary. Subsequent machining of surfaces serves multiple objectives such as improvement of dimensional accuracy, changing surface roughness and modification of the residual stress state for higher surface hardness. Beyond its several advantageous properties, Ti6Al4V material has, as its weaknesses, low tribological behavior and wear resistance. Sliding friction burnishing is a conventional chipless and coolant-free environmentally conscious technology for surface modification that is appropriate for simultaneously decreasing surface roughness and increasing surface hardness. Until now, there has been a research gap regarding the diamond burnishing of selective laser melted Ti6Al4V parts. In this study, we investigated how the surface roughness of selective laser melted p...

Machines, 2022

Surface roughness is an important factor in metal cutting, and usually different surface roughnes... more Surface roughness is an important factor in metal cutting, and usually different surface roughness characteristics are used to control the quality of the machined surfaces. However, as the cutting tool wears out during the cutting process, the roughness values change. In most cases, theoretical roughness values are calculated without taking the wear characteristics of the tool into account. For this reason, the calculated and measured roughness values may differ from each other, and the tendency of their change may also be different. This paper presents a method for the determination of the theoretical roughness of hard turned surfaces considering the wear of the cutting tool. The purpose of the analyses performed was to show the effect of wear trace on the tool and the roughness of the machined surface and to give a possible method to take the wear into account when calculating the theoretical roughness values. During the investigations, the shape of the actual (worn) edge section ...

In this study the technology of lifetime increasing surface strengthening burnishing process is i... more In this study the technology of lifetime increasing surface strengthening burnishing process is inestigated presentig the results related to it. We analyze the effect of setting parameters (burnishing force, feed rate, speed, number of passes) to the surface micro-hardness and stress condition and examine the correlation relationships between them. To planning and executing the experiments use full factorial experimental design method is applied.

Cold plastic finish manufacturing methods such as surface rolling, burnishing and surface hardeni... more Cold 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 ...

Fiatal Műszakiak Tudományos Ülésszaka, 2002

The paper contains the analysis of one of the functionally delimitable partial fíelds of the elas... more The paper contains the analysis of one of the functionally delimitable partial fíelds of the elastic automation of production, which is the tool supply. It touches upon partial fields of tool

Fiatal Műszakiak Tudományos Ülésszaka, 2008

This paper emphasizes the use of environmentally friendly metal cutting technologies, dealing wit... more This paper emphasizes the use of environmentally friendly metal cutting technologies, dealing with the application of minimal volume of coolants and lubricants. When using bio-oils the use of mineral oils can be avoided. Összefoglalás A dolgozat a környezetbarát megmunkálási technológiák használatát hangsúlyozza. Foglalkozik a minimális kenés alkalmazásával és az ásványi olajok használatának csökkentési kérdésével és a növényi olajak felhasználásával. Köszönetnyilvánítás A szerzők megköszönik a T 42843 számú OTKA támogatását.

IOP Conference Series: Materials Science and Engineering, 2019

Tribological processes and failure of plain bearings significantly affect the availability, adapt... more Tribological processes and failure of plain bearings significantly affect the availability, adaptability, reliability and productivity of modern technology, maintenance costs, energy costs and the costs of modern production. The research of tribological processes and failure of plain bearings should indicate the possible causes and the necessary measures to be applied in order to reduce the tribological processes and failure of plain bearings. In this paper, possible causes of tribological processes and failure of plain bearings were analyzed. Having in mind the most important causes of tribological processes and failure, a proposal for monitoring the condition is given.

Cutting & Tools in Technological System, 2019

Cold-plastic forming technologies are one of the most dynamically developing technological proces... more Cold-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 the 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 and 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.

IOP Conference Series: Materials Science and Engineering, 2018

Machining performance can be improved by cooling with cryogenic assistance. This paper focuses on... more Machining performance can be improved by cooling with cryogenic assistance. This paper focuses on the influence of cryogenic cooling conditions using dry ice, solid carbon dioxide when drilling of PE-HD1000 plastic parts. The goal was to determine how the surface roughness of the drilled hole changes as a function of the cutting speed and the feed rate at room temperature and when cryogenic cooling is applied. The function relations were determined using Factorial Experiment Design. Improvement of the machinability of low temperature drilling results the improvement of roughness of the drilled hole.

Fiatal Műszakiak Tudományos Ülésszaka, 2007

This paper emphasis the to use the environmentally friendly metal cutting technologies. This arti... more This paper emphasis the to use the environmentally friendly metal cutting technologies. This article deal with the application of minimal volume of coolants and lubricants. When using synthetic oils and bio-oils the use of mineral oils can be avoiled. Összefoglalás A dolgozat a környezetbarát megmunkálási technológiák használatát hangsúlyozza. Foglalkozik a minimális kenés alkalmazásával és az ásványi olajok alkalmazásának mellőzésével és a szintetikus illetve a növényi olajok felhasználásával.

Multidiszciplináris tudományok

A befejező megmunkálási műveletek között a vasalás egy gazdaságos, kis környezetterhelésű eljárás... more A befejező megmunkálási műveletek között a vasalás egy gazdaságos, kis környezetterhelésű eljárás. Speciális esetekben a köszörülés helyettesíthető vasalással, sokkal kisebb környezeti terhelés mellett ugyanazt az érdességet hozva létre. A vizsgálat célja a vasalási folyamat technológiai paramétereinek a felületi érdességre és keménységre gyakorolt hatásának meghatározása volt. A vasalási kísérleteket X5CrNi18-10 rozsdamentes acél próbatesteken végeztük. A kísérleti vizsgálatok során alkalmazott vasalási paraméterek a vasalási sebesség, előtolás és az erő voltak. A kísérletek megvalósítása a teljes faktoriális kísérlettervezési módszer alkalmazásával történtek. A mért eredmények kiértékelése után megállapítható volt, hogy vasalás hatására a Vickers-keménységa vasalás előtti HV: 330 –370 értékről HV: 380-490 értékre nőtt, míg az érdesség Ra: 0,39-1,24 μm értékről 0,16-0,32 μm értékre csökkent. A 2D és 3D felületi érdesség paramétereket AltiSurf 520 3D-s kromatikus érdesség mérő beren...

Periodica Polytechnica Mechanical Engineering

Selective laser melting (SLM) is a frequently used additive manufacturing technology for creating... more Selective laser melting (SLM) is a frequently used additive manufacturing technology for creating metallic, especially Ti6Al4V parts. After the production by SLM usually postprocessing is necessary for several reasons. Here the sliding friction diamond burnishing is applied as postprocessing procedure.In this paper an experimental study of surface hardness improvement of selective laser melted Ti6Al4V ELI cylindrical parts is demonstrated. The surface is modified by sliding friction diamond burnishing as postprocessing machining. The design of experiment method was applied to investigate effect of five factors (two SLM and three machining parameters) on surface hardness modification.It is shown that both SLM and postprocessing factors makes significant effect to the surface hardness improvement, most important ones are laser power, laser scan speed during manufacturing, and the burnishing force as factor of postprocessing. Empirical formulas are fit to measurement data, and visualiz...

Rad prikazuje tehnologiju izrade trakastog transportera (materijala AISI 304L) od modeliranja dij... more Rad prikazuje tehnologiju izrade trakastog transportera (materijala AISI 304L) od modeliranja dijelova uz pomoć računala, sklapanja svih dijelova transportera u virtualni sklop i izradu dijelova transportera primjenom CAD-CAM povezivanja. Proizvodnja korištenjem CAD-CAM pristupa se može optimizirati i lako kontrolirati, iz čega proizlazi brža, kvalitetnija i efikasnija proizvodnja.

Lecture notes in mechanical engineering, Oct 20, 2017

In the paper, the experimental results of the study on the dynamic characteristics of the air gau... more In the paper, the experimental results of the study on the dynamic characteristics of the air gauges are presented. Dynamical properties of the air gauge are dependent mainly on the pressure transducer type and also on the geometry of its flow-through elements. The present investigations focused on the diameter of the inlet nozzle and its impact on the time constant and the frequency at which the dynamic error would not exceed 5%. It was proved that in the most common configurations of the air gauges, those two parameters may vary up to 100%, and the dynamics of the air gauges worsened with smaller inlet nozzles. The results are of high practical importance in industrial measurement systems where the air gauges are applied, because the multiplication of the air gauge is typically set by the adjustment or replacement of the inlet nozzle.

Multidiszciplináris tudományok, 2021

One of the defining global issues today is to reduce the load on the environment. Thus, in this p... more One of the defining global issues today is to reduce the load on the environment. Thus, in this paper, the effect, and consequences of the abandonment of cooling and lubrication were investigated when turning of non-alloyed steel. The 2D and 3D surface roughness parameters, cylindricity deviations and circularity errors were examined at different feeds and cutting speeds. The experiments were performed, using the full factorial experimental design method. It was found that with dry machining, the average roughness is slightly higher with increasing productivity, however, at lower feed and cutting speeds, the surface has better wear resistance and lubricant retention, and cylindricity deviation can be minimized.

Department of Production Engineering at College of Nyiregyhaza and Department of Production Engin... more Department of Production Engineering at College of Nyiregyhaza and Department of Production Engineering at University of Miskolc cooperates in research of environmentally conscious machining by experimental and simulation methods. In this paper we develop previous modelling results. The aim is quasi-static investigation of the mechanical interaction between the drilling tool and the workpiece. The phenomenon is simulated as contact problem. Forces and torques applied in the simulation comes from experiments. This study gives insight to the mechanical interaction during the machining, and prepares further dynamical investigations.

Proceedings of the Thirty-First International Matador Conference, 1995

The operational features (efficiency, sound pressure, transmissible power, etc.) of worm driving ... more The operational features (efficiency, sound pressure, transmissible power, etc.) of worm driving pairs are basically determined by the oil film formed between the mating surfaces. The design parameters and technological parameters play the main role in the favourable formation of oil film. During design those geometrical parameters, which make possible the formation of appropriate oil film and optimum bearing pattern can be determined. With the help of our mathematical model the optimal design of any cylindrical or conical helicoidal surface can be accomplished. The finishing manufacturing operation of worms can be performed by the use of continuons grinding wheel truing equipment. The basis of geometrical dimensioning of tools necessary for production of worm gears will be shown. The optimal bearing pattern can be adjusted during the assembling of already produced elements of worm driving pairs.

IOP Conference Series: Materials Science and Engineering, 2018

Increasing the cutting speed and/or the feed rate is often chosen to increase the efficiency of t... more Increasing the cutting speed and/or the feed rate is often chosen to increase the efficiency of the material removal. Of course, there are limits to the selection of specific values in both cases, such as, the rigidity of the machining system, the loadability and lifetime of the cutting edges, the prescribed roughness values of the surfaces, etc. When increasing the feedrate in face milling, the conditions of the chip removal change considerably, because at low feed values, the material forming effect of the side edge (i.e. the edge on the lateral surface of the tool) is the most determinative and the chip deforms perpendicular to it, while increasing the feed gradually moves the determinative part of the chip removal to the edge which lies perpendicular to the tool axis. Therefore, both of the two edges have a distinct role in chip removal due to both their position and geometry. The two edges are located on one cutting insert; therefore, their geometry needs to be examined individually and collectively in the search for the most suitable for effective chip removal. The study investigates how the different tool geometrical characteristics affect the roughness parameters of surfaces in normal and in highfeed face milling.

Machines

Additively manufactured metallic parts usually need postprocessing in order to achieve required s... more Additively manufactured metallic parts usually need postprocessing in order to achieve required shape accuracy. Cylindrical test specimens were produced by selective laser melting from Ti6Al4V powder material with different processing parameters. The aim of postprocessing was modification of shape accuracy. Sliding friction diamond burnishing was applied as the postprocessing method. A five-factor, two-level full factorial design of experiment was implemented with factors being infill laser power, infill laser scan speed, burnishing speed, feed and force. Improvement ratios of two roundness parameters were defined, calculated from experimental data, and studied by main effect and interaction analysis. It has been demonstrated that burnishing feed has the largest main effect to improvement in roundness total and cylindricity. Additionally, parameters of both selective laser melting and diamond burnishing appear in three largest interaction terms. Empirical functions were fit to measu...

Machines

This study describes the determination and optimization of burnishing process parameters and thei... more This study describes the determination and optimization of burnishing process parameters and their effects on surface roughness of EN AW-2011 aluminium alloy workpieces. The process has a low environmental load and the chip-free burnishing process improves the integrity of the machined surface, but to achieve this, the different burnishing parameters, for example, burnishing force, feed rate, speed and number of passes, must be properly defined according to the material of the workpiece. In our research, a full factorial experimental design method is used to plan and carry out the experiments and to determine the most appropriate parameter range for this material quality.

Machines

Selective laser melting is a frequently used, powder bed fusion additive manufacturing technology... more Selective laser melting is a frequently used, powder bed fusion additive manufacturing technology for producing metallic parts. However, appropriate surface quality cannot be achieved, so post-processing is often necessary. Subsequent machining of surfaces serves multiple objectives such as improvement of dimensional accuracy, changing surface roughness and modification of the residual stress state for higher surface hardness. Beyond its several advantageous properties, Ti6Al4V material has, as its weaknesses, low tribological behavior and wear resistance. Sliding friction burnishing is a conventional chipless and coolant-free environmentally conscious technology for surface modification that is appropriate for simultaneously decreasing surface roughness and increasing surface hardness. Until now, there has been a research gap regarding the diamond burnishing of selective laser melted Ti6Al4V parts. In this study, we investigated how the surface roughness of selective laser melted p...

Machines, 2022

Surface roughness is an important factor in metal cutting, and usually different surface roughnes... more Surface roughness is an important factor in metal cutting, and usually different surface roughness characteristics are used to control the quality of the machined surfaces. However, as the cutting tool wears out during the cutting process, the roughness values change. In most cases, theoretical roughness values are calculated without taking the wear characteristics of the tool into account. For this reason, the calculated and measured roughness values may differ from each other, and the tendency of their change may also be different. This paper presents a method for the determination of the theoretical roughness of hard turned surfaces considering the wear of the cutting tool. The purpose of the analyses performed was to show the effect of wear trace on the tool and the roughness of the machined surface and to give a possible method to take the wear into account when calculating the theoretical roughness values. During the investigations, the shape of the actual (worn) edge section ...

In this study the technology of lifetime increasing surface strengthening burnishing process is i... more In this study the technology of lifetime increasing surface strengthening burnishing process is inestigated presentig the results related to it. We analyze the effect of setting parameters (burnishing force, feed rate, speed, number of passes) to the surface micro-hardness and stress condition and examine the correlation relationships between them. To planning and executing the experiments use full factorial experimental design method is applied.

Cold plastic finish manufacturing methods such as surface rolling, burnishing and surface hardeni... more Cold 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 ...

Fiatal Műszakiak Tudományos Ülésszaka, 2002

The paper contains the analysis of one of the functionally delimitable partial fíelds of the elas... more The paper contains the analysis of one of the functionally delimitable partial fíelds of the elastic automation of production, which is the tool supply. It touches upon partial fields of tool

Fiatal Műszakiak Tudományos Ülésszaka, 2008

This paper emphasizes the use of environmentally friendly metal cutting technologies, dealing wit... more This paper emphasizes the use of environmentally friendly metal cutting technologies, dealing with the application of minimal volume of coolants and lubricants. When using bio-oils the use of mineral oils can be avoided. Összefoglalás A dolgozat a környezetbarát megmunkálási technológiák használatát hangsúlyozza. Foglalkozik a minimális kenés alkalmazásával és az ásványi olajok használatának csökkentési kérdésével és a növényi olajak felhasználásával. Köszönetnyilvánítás A szerzők megköszönik a T 42843 számú OTKA támogatását.

IOP Conference Series: Materials Science and Engineering, 2019

Tribological processes and failure of plain bearings significantly affect the availability, adapt... more Tribological processes and failure of plain bearings significantly affect the availability, adaptability, reliability and productivity of modern technology, maintenance costs, energy costs and the costs of modern production. The research of tribological processes and failure of plain bearings should indicate the possible causes and the necessary measures to be applied in order to reduce the tribological processes and failure of plain bearings. In this paper, possible causes of tribological processes and failure of plain bearings were analyzed. Having in mind the most important causes of tribological processes and failure, a proposal for monitoring the condition is given.

Cutting & Tools in Technological System, 2019

Cold-plastic forming technologies are one of the most dynamically developing technological proces... more Cold-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 the 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 and 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.

IOP Conference Series: Materials Science and Engineering, 2018

Machining performance can be improved by cooling with cryogenic assistance. This paper focuses on... more Machining performance can be improved by cooling with cryogenic assistance. This paper focuses on the influence of cryogenic cooling conditions using dry ice, solid carbon dioxide when drilling of PE-HD1000 plastic parts. The goal was to determine how the surface roughness of the drilled hole changes as a function of the cutting speed and the feed rate at room temperature and when cryogenic cooling is applied. The function relations were determined using Factorial Experiment Design. Improvement of the machinability of low temperature drilling results the improvement of roughness of the drilled hole.

Fiatal Műszakiak Tudományos Ülésszaka, 2007

This paper emphasis the to use the environmentally friendly metal cutting technologies. This arti... more This paper emphasis the to use the environmentally friendly metal cutting technologies. This article deal with the application of minimal volume of coolants and lubricants. When using synthetic oils and bio-oils the use of mineral oils can be avoiled. Összefoglalás A dolgozat a környezetbarát megmunkálási technológiák használatát hangsúlyozza. Foglalkozik a minimális kenés alkalmazásával és az ásványi olajok alkalmazásának mellőzésével és a szintetikus illetve a növényi olajok felhasználásával.

Multidiszciplináris tudományok

A befejező megmunkálási műveletek között a vasalás egy gazdaságos, kis környezetterhelésű eljárás... more A befejező megmunkálási műveletek között a vasalás egy gazdaságos, kis környezetterhelésű eljárás. Speciális esetekben a köszörülés helyettesíthető vasalással, sokkal kisebb környezeti terhelés mellett ugyanazt az érdességet hozva létre. A vizsgálat célja a vasalási folyamat technológiai paramétereinek a felületi érdességre és keménységre gyakorolt hatásának meghatározása volt. A vasalási kísérleteket X5CrNi18-10 rozsdamentes acél próbatesteken végeztük. A kísérleti vizsgálatok során alkalmazott vasalási paraméterek a vasalási sebesség, előtolás és az erő voltak. A kísérletek megvalósítása a teljes faktoriális kísérlettervezési módszer alkalmazásával történtek. A mért eredmények kiértékelése után megállapítható volt, hogy vasalás hatására a Vickers-keménységa vasalás előtti HV: 330 –370 értékről HV: 380-490 értékre nőtt, míg az érdesség Ra: 0,39-1,24 μm értékről 0,16-0,32 μm értékre csökkent. A 2D és 3D felületi érdesség paramétereket AltiSurf 520 3D-s kromatikus érdesség mérő beren...

Periodica Polytechnica Mechanical Engineering

Selective laser melting (SLM) is a frequently used additive manufacturing technology for creating... more Selective laser melting (SLM) is a frequently used additive manufacturing technology for creating metallic, especially Ti6Al4V parts. After the production by SLM usually postprocessing is necessary for several reasons. Here the sliding friction diamond burnishing is applied as postprocessing procedure.In this paper an experimental study of surface hardness improvement of selective laser melted Ti6Al4V ELI cylindrical parts is demonstrated. The surface is modified by sliding friction diamond burnishing as postprocessing machining. The design of experiment method was applied to investigate effect of five factors (two SLM and three machining parameters) on surface hardness modification.It is shown that both SLM and postprocessing factors makes significant effect to the surface hardness improvement, most important ones are laser power, laser scan speed during manufacturing, and the burnishing force as factor of postprocessing. Empirical formulas are fit to measurement data, and visualiz...