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1

Simulation of displacement of cutting tool holders used for turning

Mautner Viktor, Horvat Katarina, Stoić Marija, Stoić Antun

Technologia i Automatyzacja Montażu

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2023

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nr 2

41--49

EN

This paper gives a comparison of the deformation and deflection of two types of tool holders used in turning processes. Comparison of the deflection and stresses has been performed on the location where the highest value of deflection can be measured i.e. on the tip of the cutting insert. Selected tool holder types (TH1 and TH2) have rectangular and polygonal shank. Tool holders were 3D modelled in SolidWorks and Autodesk Inventor software packages and exposed to the loading with ANSYS structural analysis FEM software. In FEM analysis, two elements size of the network are selected (mesh size 5 and 1 mm). The simulation was carried out for five different loading values acting on the tool holder model. Obtained results confirm lower deflections on CAPTO tool holders.

PL

W artykule porównano odkształcenie i ugięcie dwóch typów oprawek narzędziowych stosowanych w procesach toczenia. Porównanie ugięcia i naprężeń wykonano w miejscu, w którym można zmierzyć największą wartość ugięcia, czyli na czubku płytki skrawającej. Wybrane typy oprawek narzędziowych (TH1 i TH2) mają chwyt prostokątny i wielokątny. Uchwyty narzędziowe zostały wymodelowane w 3D w pakietach oprogramowania SolidWorks i Autodesk Inventor i poddane obciążeniu za pomocą oprogramowania do analizy strukturalnej FEM ANSYS. W analizie MES wybierane są dwa rozmiary elementów sieci (rozmiar oczek 5 i 1 mm). Symulację przeprowadzono dla pięciu różnych wartości obciążeń działających na model oprawki. Uzyskane wyniki potwierdzają mniejsze naprężenia i ugięcia oprawek narzędziowych CAPTO.

2

Analysis of segmental coordination in the lower extremity using vector coding: a pilot return-to-play study of acute ankle sprain

Yang Xiaoyi, Jiang Hanhui, Yu Peimin, Mei Qichang, Fernandez Justin, Gu Yaodong

Acta of Bioengineering and Biomechanics

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2023

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Vol. 25, no. 4

EN

Background: Acute ankle sprain may affect ankle function during sport and daily activities. This study aimed to use vector coding technique to analyze the difference over time between injured and healthy lower limb during the first week of acute ankle sprain phase (P1) and post a 1-month recovery phase (P2) to understand the return-to-play coordination strategy in the lower extremity. Methods: Six females attended the gait experiments with attached 40 reflective markers using eight camera Vicon motion capture system. All participants walked barefoot while turning in four directions (T0°, T45°, T90°, T135°) at their self-selected speed. Coordination patterns were classified as in-phase, anti-phase, proximal or distal dominancy between lower limb joints involving hip, knee, ankle, subtalar, metatarsophalangeal (MTP) joint and tarsometatarsal (TMT) joint. Results: P1 showed more proximal joint dominant in Hip-Knee coupling angles but P2 displayed more distal joint dominant in Knee-Ankle joint coordination pattern and mainly distal joint dominant in Ankle-MTP coupling angle mapping. The Ankle-TMT1 and Ankle-TMT5 coordination patterns matched best in straight walking but worst in T135 walking. Conclusions: Investigating inter-segmental coordination in different turning movements could provide insights into gait changes from acute ankle sprain from one-month return-to-play recovery. Knowledge of lower limb coordination pattern may provide clinical implications to improve dynamic balance and gait stability for individuals with acute ankle sprain.

3

Analysis of the influence of turning parameters of CuZn39Pb3 and AW 6060 materials on surface roughness

Tomczewski Leszek, Muszyńska-Pałys Jagoda

Technologia i Automatyzacja Montażu

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2022

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nr 2

8--14

EN

The article presents an analysis of the turning parameters of two non-ferrous materials. The tested materials were: brass CuZn39Pb3 and aluminum alloy AW 6060. A Kyocera turning knife and a WNMG 080404 AH plate were used to make the samples. Three parameters were tested: rotational speed, feed and depth of cut at three levels of variability. The roughness parameters Ra and Rz were selected for the analysis. On the basis of the obtained results, it was shown that the feed used during machining has the greatest influence on roughness, while the change of depth or cutting speed does not cause significant differences in roughness.

PL

W artykule przedstawiono analizę parametrów toczenia dwóch materiałów nieżelaznych. Materiałami poddanymi badaniom były: mosiądz CuZn39 Pb3 i stop aluminium AW 6060. Do wykonania próbek użyto noża tokarskiego firmy Kyocera i płytki WNMG080404AH tej firmy. Badaniom poddano trzy parametry: prędkość obrotową, posuw i głębokość skrawania na trzech poziomach zmienności. Do analizy wybrano parametr chropowatości Ra i Rz. Na podstawie uzyskanych wyników wykazano, że największy wpływ na chropowatość ma posuw stosowany podczas obróbki, natomiast zmiana głębokości czy tez prędkości skrawania nie powoduje znaczących różnić w chropowatości.

4

Wpływ geometrii płytek skrawających na chropowatość powierzchni w obróbce wykończeniowej

Osak Mateusz, Żyłka Wojciech

Obróbka Metalu

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2022

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nr 1

32--36

PL

W artykule przedstawiono badania wpływu geometrii płytek tokarskich na chropowatość powierzchni. Obróbce toczeniem poddano dwa rodzaje stali: 1.0503 (C45) oraz 1.6582 (34CrNiMo6) w formie wałka o średnicy Ø 50. Badano otrzymaną chropowatość powierzchni toczonych trzema rodzajami płytek DCET 11T3005R (z geometrią ostrza Wiper), WNMG080404, VBMT160404. Wyniki badań jednoznacznie wykazały, że powierzchnie obrobione płytkami typu Wiper charakteryzują się mniejszymi wartościami parametrów chropowatości niż obrobione płytkami o geometrii standardowej.

EN

In this paper investigates how the geometry of turning plates affects the surface roughness were described. Two steel types were machined: 1. 0503 (C45) and 1. 6582 (34CrNiMo6) in the form of a shaft with a diameter of Ø50. The resulting surface roughness was investigated with three plate types DCET 11T3005R (with Wiper geometry), WNMG080 404, VBMT160 404. The test results clearly showed that surfaces treated with Wiper geometry plates have lower roughness parameters than plates with standard geometry.

5

Vibration analysis of a turning tool with passive damping

Klamczyński Kamil

Mechanik

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2022

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R. 95, nr 10

40--46

EN

Mechanical vibrations generated during machining can cause many problems in production processes. Vibrations can cause high dynamic loads leading to damage of the machine spindle, the cutting tool or the workpiece. Another unwanted effect of the existence of vibration during the machining process can be a deterioration in the quality of the machined surface. In this paper, a comparative analysis was carried out based on studies of the face turning process with conventional knives and those equipped with passive vibration damping systems. The results show the influence of the implemented vibration damper on the cutting process.

PL

Drgania mechaniczne pojawiające się podczas obróbki skrawaniem mogą być przyczyną występowania wielu problemów w procesach produkcyjnych. Drgania mogą powodować duże obciążenia dynamiczne prowadzące do uszkodzenia wrzeciona obrabiarki, narzędzia skrawającego lub przedmiotu obrabianego. Innym niepożądanym efektem występowania drgań w czasie procesu obróbki mechanicznej może być pogorszenie jakości obrabianej powierzchni. W niniejszej pracy przeprowadzono analizę porównawczą na podstawie badań procesu toczenia czołowego powierzchni nożami konwencjonalnymi i wyposażonymi w pasywne systemy tłumienia drgań. Wyniki badań przedstawiają wpływ zastosowanego tłumika drgań na przebieg procesu skrawania.

6

Performance optimisation of the turning process along with multi-surface heating process

Sathish Kumar D., Thanigaivelan R., Natarajan N.

Materials Science Poland

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2022

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Vol. 40, No. 4

1--13

EN

Materials that are difficult to cut possess excellent qualities and machinability, though conventional machining techniques require additional energy to circumvent the problems associated with the turning process. In this study, heat-assisted turning of duplex stainless steel (SS) was carried out. Various heating techniques such as infrared (IR)-, ultraviolet (UV)- and hot air(HA)-assisted heating were adopted. The experiment used an L16 orthogonal array with the most significant parameters such as heating method, feed rate in millimetres per revolution (mm/rev), depth of cut (millimetres [mm]) and cutting speed (metres per minute [m/min])on the cutting force and surface roughness. The technique for order performance by similarity to ideal solution (TOPSIS) and grey relational analysis (GRA), were used to optimise the output performance. The results of TOPSIS showed that the 16th experimental combination, i.e., the HA heating method, with feed rate = 0.175 mm/rev, depth of cut = 0.1 mm and cutting speed = 150 m/min, required a smaller cutting force and resulted in lower surface roughness. In case of the GRA method, the best output performance was observed for the 15th experimental combination, that is, the HA heating method, with feed rate = 0.15 mm/rev, depth of cut = 0.2 mm and cutting speed = 200 m/min. Compared to the non-heat-assisted turning process, the HA- and UV-assisted processes required 10.25% and 7.69% lesser cutting force, respectively, and the surface roughness in case of the HA method was 15.13% lesser.

7

A simplistic regression-based genetic algorithm optimization of tool-work interface temperature

Utkarsh, Kumar Saumya, Kumar Saaransh, Kiran G. Uday, Mukhopadhyay Arkadeb, Barman Manik

Engineering Transactions

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2022

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Vol. 70, iss. 2

141--156

EN

This work aims to investigate the average tool-work interface temperature for the HSS tool and AISI 1040 steel pair. A tool-work thermocouple is proposed for the measurement of temperature because of its simple construction in addition to the low cost. The machining process of AISI 1040 steel is considered due to its extensive application, including industry usage. The changes in cutting temperature are studied for combinations of cutting speed, feed and the depth of cut during turning operation. The orthogonal array L9 by Taguchi is adopted for designing the experiments within a restricted set of runs. The average cutting temperature shows an increasing curve with functions of speed versus depth of cut and speed versus feed. But no clear trend is observed for a combination of feed versus depth of cut. A second-order regression equation with reasonable accuracy (R 2 = 0.99) is fitted using the data. Analysis of variance (ANOVA) reveals the highest contribution from cutting speed, which influences average temperature at the interface of tool and work. Further, the genetic algorithm predicts an optimal combination of parameters, which is 82.542 m/min cutting speed, 0.276 mm/rev feed rate and 0.2 mm depth.

8

Experimental study of the wear behaviour of a metal carbide tool in turning by dimensionless analysis

Amier F.D., Belarifi F., Noureddine R.

Archives of Materials Science and Engineering

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2022

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Vol. 114, nr 1

5--12

EN

Purpose: In this article, we present the experimental results with a dimensionless analysis of the wear behavior of a metal carbide tool in a turning operation. Design/methodology/approach: The highlighting of the dimensional input and output parameters of the experimental tests to bring out the different adimensional parameters. Regarding the input parameters, we have the rotational velocity (N), the feed (f), the depth of cut (ap), the machining time (t). The output parameters are defined by the flow rate (DC), the volume of the used tip (VU), the face wear (VB), as well as the cutting power (PC) and that of the machine (PM). Findings: The dimensionless approach allowed us to find the desired cutting conditions as well as the possibility of working in ranges of cutting conditions for known wear, which is not possible with a dimensional analysis. It should be noted that the appropriate choice of these parameters was essential to achieve these results. Research limitations/implications: The existence of a working range proposed by this analysis leads us to the proposal of a model and a numerical optimization. Practical implications: This work offers the desired compromise of adequate cutting conditions during machining. Originality/value: Deduction of adequate cutting conditions with minimum wear. Among other things, we can extrapolate the results to offer us compromises in the choice of ranges of cutting conditions.

9

To decrease the turning-induced pitting susceptibility of laser-cladded Fe–Cr–Ni layer by low plasticity burnishing

Zhang Peirong, Hu Shunrui, Lv Tao, Du Jin, Su Guosheng, Liu Zhanqiang, Xu Chonghai

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 4

art. no. e179, 2022

EN

Corrosion resistance of machined surface and its correlation with surface roughness have been the important concerns for sustainability of the final products. However, the pitting corrosion of laser-cladded Fe–Cr–Ni layers by turning exhibits susceptibility to surface roughness characteristics. In present study, the generation mechanism of pitting susceptibility by turning and the effect of burnishing on decreasing the pitting susceptibility were explored. To this end, a theoretical model of the potential difference between roughness peaks and valleys was established with considering the functional parameters of the surface roughness. Then, the correlations between the potential difference and pitting characteristics including pitting depth, width and area were analyzed in order to reveal the generation mechanism of pitting susceptibility. The occurrence of pitting corrosion could be predicted by the local potential difference, which was higher at the location where pitting corrosion would occur while lower where pitting corrosion did not occur. Finally, the influence of each functional parameter of surface roughness on the potential difference was analyzed using the proposed model, with which the machining schematics were discussed. On the basis of this research, it was expected to improve the corrosion resistance of the claddings by turning and subsequent burnishing process chain.

10

Study on Chip Breakability Index During Longitudinal Turning of Cast and DMLS Additively Manufactured AlSi10Mg Aluminum Alloy

Struzikiewicz Grzegorz, Słodki Bogdan, Zębala Wojciech, Franczyk Emilia

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 1

28--35

EN

The article presents selected issues related to the process of turning samples made of the AlSi10Mg alloy with the use of various manufacturing technologies, i.e. casting and DMLS (Direct Metal Laser Sintering). Machining processes of cylindrical surfaces of samples made with these two methods were subjected to a comparative analysis. The main idea behind the research was to develop guidelines for turning parts obtained using laser powder sintering. Study on the influence of cutting parameters on the value of breakability index Cin. as well as the type, shape and form of chips produced during longitudinal turning is presented. The chips were also measured and the results of the microscopic analysis of the chips form are described. Results showed that the values of Cin index for turning of the cast AlSi10MG alloy depend mainly on the value of feed f. According to adopted chip classification for the feed value of f > 0.1 mm/rev the chips had a favorable, short form. In the case of turning the sample obtained by the DMLS method, the values of the chip breakability index Cin are not significantly dependent on the adopted ranges of cutting parameters. The Taguchi method was used to develop the conclusions obtained on the basis of the research results.

11

Analysis of the Impact of Wiper Geometry Insert on Surface Roughness and Chips in Machining Materials Used in the Aviation Industry

Szablewski Piotr, Smak Krzysztof, Krawczyk Bartłomiej

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 1

203--212

EN

Nowadays, great emphasis is placed on increasing the efficiency of machining processes. However, this cannot be done at the expense of quality worsening of the machined surface. In this paper the influence of Wiper geometry on Ra and Rz surface roughness parameters is described when finishing turning of materials used in the aviation industry: austenitic stainless steel XCrNiNb18-9, low alloy steel 14NiCr14 and aluminum alloy A356, as well as the chips generated in the cutting process in terms of shape were assessed. It was found that for the lowest tested feed rate during turning with a Wiper insert, the values of Ra and Rz parameters do not differ significantly from the roughness parameters obtained during machining with a conventional insert. The beneficial effect of feed rate on surface roughness for the Wiper insert is clearly visible above f ≥ 0.12 mm/rev. The biggest difference in roughness parameters was recorded for the highest value of the applied feed f = 0.28 mm/rev. Using conventional insert, Ra and Rz values are almost three times bigger than for Wiper insert. The influence of the cutting speed on the Ra and Rz parameters depends on the type of material being processed. Increasing cutting speed from vc =120 m/min to vc = 200 m/min for stainless steel, Ra and Rz values decrease about 35%. Similar situation noticed for aluminum alloy, but increasing cutting speed decrease Ra and Rz values only about 18%. The situation is different for low alloy steel. Increasing the cutting speed increases the Ra and Rz parameters by about 37%. Rz/Ra ratio shows that for feed rate f ≤ 0.12 mm/rev. cutting process is unstable, because the values are between 5.5–7.5, but should oscillate around 4. Increasing feed rate value to f = 0.2 mm/rev allows to stabilize the process and the ratio value is close to 4. Wiper insert create the same form chips as a conventional insert, using the same value of feed rate.

12

Optimization of process parameters in turning of magnesium AZ91D alloy for better surface finish using genetic algorithm

Pradeep Kumar Madhesan, Venkatesan Rajamanickam, Manimurugan Manickam

Acta Innovations

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2022

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no. 43

54--62

EN

This research examined at the optimum cutting parameters for producing minimum surface roughness and maximum Material Removal Rate (MRR) when turning magnesium alloy AZ91D. Cutting speed (m/min), feed (mm/rev), and cut depth (mm) have all been considered in the experimental study. To find the best cutting parameters, Taguchi's technique and Response Surface Methodology (RSM), an evolutionary optimization techniques Genetic Algorithm (GA) and Non-dominated Sorting Genetic Algorithm-II (NSGA-II) were employed. GA gives better results of 34.04% lesser surface roughness and 15.2% higher MRR values when compared with Taguchi method. The most optimal values of surface roughness and MRR is received in multi objective optimization NSGA-II were 0.7341 µm and 9460 mm3/min for the cutting parameters cutting speed at 140.73m/min, feed rate at 0.06mm/min and 0.99mm depth of cut. Multi objective NSGA-II optimization provides several non-dominated points on Pareto Front model that can be utilized as decision making for choice among objectives.

13

Investigations on the effects of nitrogen gas in CNC machining of SS304 using Taguchi and Firefly Algorithm

Prasanth P., Sekar T., Sivapragash M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 1

art. no. e136211

EN

This work attempts to use nitrogen gas as a shielding gas at the cutting zone, as well as for cooling purposes while machining stainless steel 304 (SS304) grade by Computer Numerical Control (CNC) lathe. The major influencing parameters of speed, feed and depth of cut were selected for experimentation with three levels each. Totally 27 experiments were conducted for dry cutting and N2 gaseous conditions. The major influencing parameters are optimized using Taguchi and Firefly Algorithm (FA). The improvement in obtaining better surface roughness and Material Removal Rate (MRR) is significant and the confirmation results revealed that the deviation of the experimental results from the empirical model is found to be within 5%. A significant improvement of reduction of the specific cutting energy by 2.57% on average was achieved due to the reduction of friction at the cutting zone by nitrogen gas in CNC turning of SS 304 alloy.

14

Influence of Laser Heating on the Properties of Coated Cutting Inserts

Kupczyk M. J.

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 4

61--71

EN

The article presents the results of the influence of laser heating on the properties of replaceable cutting inserts with various anti-wear coatings. Based on the existing own and external publications, it was found that in order to improve the cutting properties (durability in the cutting process of steel), it is extremely important to increase the adhesion strength of hard coatings to the cutting inserts. For this purpose, laser heating with different values of the laser beam power density was used. First, the measurements of the adhesion, and then the wear and durability of the cutting blades in the process of longitudinal turning of the commonly used nitriding steel were carried out. In order to confirm the adhesion measurements carried out on the basis of the vibration signal evaluation, observations were additionally made using a scanning microscope and using 2D and 3D images on a profilometer. As a result of the research, it was found, among other things, a significant correlation between the values of adhesion of coatings to cemented carbide substrates and the durability of the blades in the steel turning process. A significant effect of laser heating on the above-mentioned properties of replaceable cutting inserts was observed. The most favorable value of the applied power density was determined, for which the blades have the best cutting properties. The research indicate that significant increase in adhesion and tool life can be achieved for the laser beam power density of up to 8280 W/cm2. In the most favorable case, an increase in tool life of about 48% was obtained for the indexable cutting insert with a TiCN coating when turning 41CrAlMo7-10 steel.

15

Formation of Surface Topography During Turning of AISI 1045 Steel Considering the Type of Cutting Edge Coating

Szczotkarz Natalia, Maruda Radosław W., Dębowski Daniel, Leksycki Kamil, Wojciechowski Szymon, Khanna Navneet, Królczyk Grzegorz M.

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 4

253--266

EN

The paper presents evaluation of the surface topography obtained after turning of AISI 1045 steel with the use of cemented carbide tools diversified in terms of applied titanium-based coatings. During the research, three types of coatings deposited with the PVD method on a P25 sintered carbide insert were compared: nitride-titanium TiN, nitride-aluminum-titanium TiAlN and carbon-titanium TiC in a wide range of variable cutting speeds 125 - 325 m/min and variable feeds 0.05 - 0.25 mm/rev. The quality of the machined surface was assessed on the Sensofar S neox System optical profile meter using the confocal method. The paper presents the results of 3D parameters, contour maps, isometric views and material ratio curves. The surface topography analysis showed that for the TiAlN coated insert, lower surface roughness parameters were observed in the range of lower cutting speeds and higher feeds, while for higher cutting speeds, lower values of the selected 3D parameters were found for the insert with TiC coating. For the insert with TiC coating, the most even distribution of the valleys and ridges of the machined surface roughness was also observed. The research results determined the range of cutting parameters that allow the selection of the appropriate type of titanium-based coating when machining AISI 1045 steel.

16

Influence of coefficient of friction on Ti-6Al-4V titanium alloy turning process - FEM analysis

Lisowicz Joanna

Technologia i Automatyzacja Montażu

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2020

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nr 3

22--29

EN

The good properties of Ti-6Al-4V titanium alloy make it widely used, but at the same time, make it difficult to machine. One of the factors which influence the machinability of metal alloys is coefficient of friction, which can be lowered by multiple cooling and lubricating methods. In the present work the influence of coefficient of friction on the turning process of Ti-6Al-4V was analyzed based on the FEM simulations conducted in DEFORM 2D/3D software. It was proven that the coefficient of friction influenced the cutting force and thrust force. It was also shown that the coefficient of friction had a significant impact on the chip compression ratio.

PL

Dobre właściwości stopu tytanu Ti-6Al-4V decydują o jego szerokim zastosowaniu, lecz jednocześnie wpływają na trudnoobrabialność. Jednym z czynników, który wpływa na obrabialność stopów metali jest współczynnik tarcia, którego wartość może być obniżana dzięki zastosowaniu różnych metod chłodzenia i smarowania. W niniejszej pracy przeanalizowano wpływ wartości współczynnika tarcia na przebieg procesu toczenia stopu Ti-6Al-4V, na podstawie symulacji MES przeprowadzonych w programie DEFRORM 2D/3D. Pokazano, iż współczynnik tarcia ma wpływ na wartość siły skrawania i siły odporowej. Uwidoczniono również istotny wpływ wartości współczynnika tarcia na współczynnik spęczenia wióra.

17

Frezotoczenie – hybrydowa obróbka skrawaniem

Potrzebski Marek, Styp-Rekowski Michał, Świątek Paweł, Świątek Paweł Lech

Obróbka Metalu

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2020

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nr 1

44--50

PL

W artykule w sposób syntetyczny przedstawiono frezotoczenie – niezbyt popularną ciągle metodę obróbki skrawaniem. Jest to obróbka hybrydowa stanowiąca połączenie tradycyjnych obróbek toczenia i frezowania. Przedstawiono jej zalety i wady. Przedstawiono także wyniki badań eksperymentalnych, które potwierdziły dużą przydatność frezotoczenia w praktyce przemysłowej. Jej pozytywną cechą jest wyraźnie większa efektywność obróbki w porównaniu do obróbek tradycyjnych, negatywną zaś – mniejsza dokładność. Ogranicza to w pewnym stopniu jej zastosowanie.

EN

In this paper rotating milling – a not very popular method of machining is presented in a synthetic way. It is hybrid machining which combines traditional turning and milling operations. Its advantages and disadvantages are presented. The results of experimental research, which confirmed the great usefulness of rotating milling in industrial practice are also presented. Its positive feature is significantly better machining efficiency in comparison to traditional machining, while its negative feature is worse accuracy. This feature limits its use in some applications.

18

Experimental determination of the surface geometrical structure parameters and tool wear during turning the polymer concrete

Kępczak N., Rosik R.

Mechanics and Mechanical Engineering

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2020

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Vol. 24, nr 1

1--6

EN

The paper presents the results of experimental determination of the Surface Geometrical Structure (SGS) parameters and tool wear during turning the polymer concrete. Until now, all literature reports have shown that the smoothness and roughness of the mineral cast surfacewas obtained directly from the mold. However, new applications of polymer concrete, even for some parts of the machine tools, forced the producers to carry out machining, which would improve the parameters of the surface layer. The topic of machining ceramic-based composite materials is a new chapter in the field of machining, which has not been sufficiently researched so far. The article describes the process of experimental determination of dependence of surface layer and tools wear parameters from cutting parameters during longitudinal turning of polymer concrete. The turning was carried out using plates made of a cubic boron nitride (CBN). After machining, the surface roughness and the maximum width of the flank wear were measured. On this basis, the mathematical model of the surface layer and tools wear parameters versus cutting parameters were defined. The authors also attempted to explain the phenomena occurring in the machining zone using variable cutting parameters. Microscopic pictures of CBN plates after machining were also performed. After the study, the final conclusions about the machining of mineral cast material were formulated.

19

Material identification during turning by neural network

Denkena Berend, Bergmann Benjamin, Handrup Miriam, Witt Matthias

Journal of Machine Engineering

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2020

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Vol. 20, No. 2

65--76

EN

A design concept for high-performance components involves the combination of different materials in hybrid workpieces. Different material properties and chemical compositions influence the machining quality of hybrid workpieces. To achieve a constant workpiece and process quality, it is necessary to adjust the process parameters to the individual material. Thus, it is mandatory to classify the material during machining for the relevant range of process parameters. This paper examines teaching strategies for neural networks to determine the machined material in process by a small amount of cross points. For this purpose, different training sets are compared. Process parameters with different cutting speeds, feeds and with constant and varying depth of cut are examined. In addition, the signal sources necessary for robust material classification are compared and investigated. The investigation is performed for the cylindrical turning of friction welded EN AW-6082/20MnCr5 shafts. The study shows that an F1 score of 0.99 is achieved at a constant cutting depth, provided that only the corner points of the process window and the machine control signals are used for training. With an additional variation of the cutting depth, the classification rate is significantly improved by the use of external sensors such as the acceleration sensor.

20

Reduction of Pollution During Composite Machining

Raska Jan, Hlavac Libor, Stefek Adam, Tyc Martin

Inżynieria Mineralna

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2020

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no. 1, vol. 2

175--178

EN

Machining of composite materials through classical way, i.e. using conventional tools for turning, drilling, milling, grinding and polishing, produces a lot of very small particles - dust. These particles enter the air, because machining should be performed with a minimum of sprinkling to protect composite material properties and to avoid delamination or swelling. Sometimes, even some burning of epoxide used as binder takes place during machining. Dust produced during machining of the composite material might have negative impact on health and may cause explosion. Skin inflammation or inhalation of the toxic epoxide resin, are some of the examples. Common solution of this problem is suction of particles and fume using machines creating negative pressure. Subsequent removing of these harmful substances from air is quite demanding and expensive. Moreover, using of common suction systems is many times less efficient than declared by producers.This contribution presents a new way of fighting with pollution caused by composite machining. The alternative machining tool for composite machining is abrasive water jet (AWJ). This tool is efficient in all basic machining processes and produces in air only about 1% of dangerous pollution comparing to classical tools. Progress of the AWJ machining system based on robot as a movement device is presented and the first results are commented. The main attention is aimed at machining quality possibilities. However, a part of the contemporary research focused on pollution suppression is also presented in the contribution.

PL

Obróbka materiałów kompozytowych klasycznym sposobem, tj. przy użyciu konwencjonalnych narzędzi do toczenia, wiercenia, frezowania, szlifowania i polerowania, powoduje powstawanie bardzo małych cząstek – pyłu. Cząsteczki te dostają się do powietrza, ponieważ obróbkę należy wykonywać przy minimalnym zraszaniu, aby chronić właściwości materiału kompozytowego i uniknąć rozwarstwienia lub pęcznienia. Stosowana jest również obróbka epoksydu stosowanego jako spoiwo. Pył powstający podczas obróbki materiału kompozytowego może mieć negatywny wpływ na zdrowie i spowodować wybuch. Zapalenie skóry lub wdychanie toksycznej żywicy epoksydowej to tylko niektóre z przykładów. Powszechnym rozwiązaniem tego problemu jest odsysanie cząstek i oparów za pomocą maszyn wytwarzających podciśnienie. Usunięcie tych szkodliwych substancji z powietrza jest dość wymagające i kosztowne. Co więcej, stosowanie popularnych systemów ssących jest wielokrotnie mniej wydajne niż deklarowane przez producentów. W artykule przedstawiono nowy sposób walki z zanieczyszczeniami powodowanymi przez obróbkę kompozytową. Alternatywnym sposobem do obróbki kompozytów jest ścieranie strumieniem wody (AWJ). Ten sposób jest wydajny we wszystkich podstawowych procesach obróbki i powoduje powstawanie w powietrzu tylko około 1% niebezpiecznych zanieczyszczeń w porównaniu do klasycznych narzędzi. Przedstawiono postępy systemu obróbki AWJ opartego na robocie jako urządzeniu ruchowym i komentowano pierwsze wyniki. Główna uwaga skupiona jest na możliwościach obróbki strumieniem wody. Przedstawiono również inne współczesne badania koncentrujące się na zmniejszaniu tłumieniu zanieczyszczeń z procesu obróbki kompozytów.