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1

Machining of Printed Circuit Boards Using an Industrial Robot in a Simulation Environment

Komák Martin, Pivarčiová Elena, Herčút Patrik

Management Systems in Production Engineering

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2025

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nr 3 (33)

433-442

EN

This paper is devoted to the design, simulation, and optimization of a robotic cell designed to machining printed circuit boards (PCBs) using a stationary milling machine mounted on an industrial robot. The main goal was to create a digital model of the production workplace in the RobotStudio environment, which allows testing robot movements, program logic, and functional arrangement of the entire system prior to physical implementation. The use of offline programming reduces costs and risks, enables rapid tuning of robot paths, and minimizes collision states. An important part of the design was the creation of a custom gripper made by 3D printing. This gripper combines vacuum suction cups with pneumatic clamping, which allows gentle manipulation of PCBs without damaging electronic components. The created cell model includes a conveyor system, a milling machine, a protective Plexiglas cover, and a camera to recognize PCB types. The simulation confirmed the functionality of the entire cycle, the optimized length of which is 56.58 s. The results show the potential of digital design for automated manufacturing cells and open the space for future research in the field of effectors, advanced control, and artificial intelligence in industrial automation.

2

Research on the main and side surfaces after face milling of polymer composites

Ciecieląg Krzysztof

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 12

17--29

EN

The article presents research on glass and carbon fiber reinforced plastics. The main and side surfaces of the composites were machined using face milling. A milling cutter with polycrystalline diamond inserts was used for the research. The composite materials were tested under variable milling parameters for two types of surfaces and two polymer composites. A novelty presented in the article is the comparative study of the main and side surfaces of two composite materials using 3D topography maps and material bearing ratio for the same milling parameters. The paper also includes plots showing roughness parameters as a function of changing technological parameters for two composite machining areas. The research showed that a small feed per tooth and a high cutting speed have a positive effect on surface quality. The lowest roughness parameter value of Ra 0.72 µm was achieved for the main machining of a glass fiber reinforced plastics with a feed per tooth of 0.05 mm/tooth. A high feed per tooth of 0.60 mm/tooth resulted in Ra roughness values of 2.32 µm for the carbon fiber reinforced plastics. A high cutting speed of 600 m/min during the machining of the main surface of the glass fiber reinforced plastics allowed Ra=0.52 µm to be achieved. In contrast, a low cutting speed resulted in a Ra roughness value of 1.85 µm for the side machining of the glass fiber reinforced plastics. The paper also presents material bearing ratio and 3D topography maps, which also confirm that a low feed per tooth and high cutting speed have a positive effect on surface quality.

3

Influence of machining conditions on the surface quality after circumferential milling of carbon fiber reinforced aluminum laminate

Doluk Elżbieta, Magdziak Marek, Sułkowicz Paweł, Buk Jarosław

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 10

223--237

EN

FMLs are an increasingly used group of materials due to their properties. Thanks to their advantages, they are used in many areas of industry. An example of this type of material is CARALL. This paper presents the influence of machining conditions on surface quality and cutting forces after circumferential milling of a 3-layer CARALL. The workpieces were formed by combining two different materials: EN-AW 7075-T6 aluminium alloy and Carbon Fiber Reinforced Plastics (CFRP). The effects of cutting speed (vc), feed rate (fz) and helix angle (λ) on material height difference and feed force Ff were investigated. The experiment concluded that poorer surface quality and higher cutting forces were obtained for a tool with a higher helix angle. The parameters to obtain the best surface quality (the lowest material height difference) are cutting speed of 500 m/min, feed rate of 0.08 mm/tooth and helix angle of 20°.The lowest surface accuracy (the highest material height difference) was obtained after machining with the following parameters: cutting speed of 200 m/min, feed rate of 0.08 mm/tooth and helix angle of 35°.

4

Cutting forces during milling of vertical thin-walled structures of aerospace alloys

Zagórski Krzysztof

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 7

197--210

EN

The article presents the results of the experiment conducted under controlled cutting conditions with a constant material removal rate, an increased cross-section of the cutting layer was used, tested for use in finishing. The analysis examined the influence of input factors on the measured values. Samples with a thin wall in vertical orientation were made of two materials - titanium Ti6Al4V and nickel alloy Inconel 625, which were the first input factor. Additional variable factors adopted during machining were cutting tools (a general purpose tool, a tool for efficient machining, a tool for high-speed machining) and machining strategies (side face milling and cylindrical side milling). The prepared samples contain two machined surfaces - inputs and outputs. During machining, the signal of cutting force components was recorded for them, based on which their graphs were made. In the case of side face milling of nickel alloy, an approximately 50% increase in the Fx component and an approximately twofold increase in the Fy and Fz components is observed compared to their titanium alloy counterparts. When milling titanium alloy samples, the values of the cutting force components between the strategies were similar, whereas for nickel alloy samples, milling with general-purpose and performance tools resulted in the cutting force component Fx being half as large as for the frontal approach.

5

Application of machine learning algorithms for recognizing the wear of the cutting tool during precision milling of hardened tool steel

Twardowski Paweł, Tabaszewski Maciej, Tabaszewski Mateusz, Czyżycki Jakub

Advances in Science and Technology. Research Journal

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2025

|

Vol. 19, no. 2

365--382

EN

The paper presents extensive research on tool wear and the analysis of diagnostic measures for different cutting speeds (vc). The work is divided into two parts. The first part involves conducting an experiment on a machining center, measuring the tool wear index, and recording vibration acceleration signals, followed by analyzing the obtained results. In the second part, the authors focus on determining appropriate diagnostic signal measures and their selection and applying various machine learning methods. The machine learning pertains to classifying the tool condition as operational or non-operational. The best of the tested classifiers achieved an accuracy of 0.999. Thanks to the comparative analysis, it was possible to propose a condition monitoring method that is based only on vibration acceleration without taking into account the cutting speed parameter. Vibration measurement can be performed on the spindle. In this case, the weighted accuracy value determined on the test set was 0.993. The F1 coefficient characterizing both precision and accuracy was 0.982. The authors consider this result to be satisfactory in industrial conditions. Measurement on the spindle without the need to take into account the cutting speed is easy to use in industrial practice

6

The influence of PCBN inserts microgeometry on cutting forces, surface roughness, and tool wear when milling Inconel 718

Szpunar Marcin, Zwolak Marek, Ostrowski Robert

Advances in Mechanical and Materials Engineering

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2025

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Vol. 42, nr 1

121--133

EN

This study investigates the effect of cutting edge microgeometry on the milling of Inconel 718, a superalloy widely used in aircraft engine components. Face milling tests were conducted using a Ø63 mm tool with unevenly distributed polycrystalline cubic boron nitride (PCBN) inserts, comparing inserts with a chamfered cutting edge (15° × 0.2 mm) and sharp cutting edges. The experiments examined cutting forces, surface roughness (parameters Ra and Rz), and tool wear at various cutting speeds (80–300 m/min). The results revealed that sharp inserts generated lower cutting forces compared to chamfered inserts, with the axial force being the greatest component for chamfered tools and the lowest for sharp ones. The dominant tool wear mechanism for both insert types was chipping; however, sharp inserts also exhibited built–up edge formation and, in one case, a significantly deeper crater compared to chamfered inserts which showed smaller crater depths. The study concludes that the cutting edge microgeometry significantly influences the machining performance in terms of cutting forces, surface quality, and tool wear when milling Inconel 718.

PL

W niniejszym badaniu zbadano wpływ mikrogeometrii ostrza na proces frezowania Inconelu 718, stopu wysokotemperaturowego powszechnie stosowanego w komponentach silników lotniczych. Przeprowadzono testy frezowania czołowego za pomocą narzędzia o średnicy Ø63 mm z nierównomiernie rozmieszczonymi płytkami PCBN, porównując płytki z fazowanym ostrzem (15° × 0.2 mm) i ostrymi krawędziami skrawającymi. Eksperymenty dotyczyły analizy sił skrawania, chropowatości powierzchni (parametry Ra i Rz) oraz zużycia narzędzia przy różnych prędkościach skrawania (80–300 m/min). Na podstawie wyników stwierdzono, że frezowanie z użyciem frezów ostrych generowało niższe siły skrawania w porównaniu do frezów z fazką, przy czym osiowa siła skrawania była największą składową dla narzędzi z fazką, a najmniejszą dla narzędzi ostrych. Dominującym mechanizmem zużycia narzędzia dla obu typów płytek było wykruszanie; jednakże frezy ostre wykazywały również tworzenie się narostu oraz, w jednym przypadku, znacznie głębszy krater w porównaniu do frezów z fazką, które charakteryzowały się mniejszymi głębokościami kraterów. Wyniki badań dowiodły, że mikrogeometria ostrza znacząco wpływa na parametry obróbki pod względem sił skrawania, jakości powierzchni i zużycia narzędzia podczas frezowania Inconelu 718.

7

Quality and efficiency analysis of edge preparation in S355J2N steel for welding applications

Kawiak Michał, Sajek Adam

Advances in Materials Science

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2025

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Vol. 25, nr 2(84)

17--35

EN

The process of edge preparation for welding plays a crucial role in ensuring the quality of welded structures, affecting both their mechanical properties and overall economic efficiency. The aim of this article is to present a comparative analysis of traditional oxy-fuel cutting and modern milling methods for edge preparation of S355J2N low-alloy steel, focusing on surface quality, microstructural changes, as well as economic aspects. The study was conducted on plates with thicknesses ranging from 8 to 20 mm, using bevel angles of 30° and 45°. Both straight and curved beveled edges were investigated, utilizing a self-propelled OMCA 900 beveling machine, Gerima MMB 400B and SMA 60 BER milling machines, and a PERUN PC-211A/Y11 gas torch. Surface roughness measurements, macroscopic analysis of the edges, and HV1 microhardness testing were performed. Operation times were recorded to enable a cost analysis. The results demonstrated that milling significantly reduces edge roughness—Ra values decreased by a factor of 6 to 10 compared to oxy-fuel cutting. In the case of oxy-fuel cutting, a heat-affected zone approximately 2–3 mm thick and localized surface hardening up to 250–450 HV1 were observed, while milling did not cause changes in hardness. Cost analysis showed that under Polish labor rates, the total beveling costs were comparable for both methods (approximately 2 EUR/m), whereas under average EU labor rates, milling became the more economically viable solution.

8

Effect of TIBW anti-wear coating on cutting tools for milling of nickel alloys on tool wear and integrity of state of the technological surface layer

Habrat Witold, Tymczyszyn Jarosław, Skroban Anna, Karkalos Nikolaos

Technologia i Automatyzacja Montażu

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2024

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nr 1

23--29

EN

In the article, research was carried out to determine the impact of the TiBW anti-wear coating on the operational properties of cutting tools for machining nickel alloys. The dynamics of tool wear were determined on the basis of changes in the components of the total cutting force, microscopic observation of wear on the flank surface, and observation of wear based on SEM images. The condition of the technological surface layer was also determined in the form of changes in the microstructure morphology and hardening of the surface layer. The research was compared to a reference tool with the same geometry with an AlTiN coating. It was shown, among other things, that TiBW coatings can be used successfully for cutting tools for machining nickel alloys, and that the wear dynamics is similar to those of tools with the AlTiN coating. The analyses confirmed the significant thermomechanical impact of the cutter during machining, manifested by chipping and a tendency to strengthen the processed material. On the basis of observations of the microstructure of the surface layer after processing, it was shown that the thermal conductivity of the TiBW coating may be lower than that of the AlTiN coating, which is reflected in the different depths of the thermomechanical interaction zones.

PL

W ramach przeprowadzonych badan określono wpływ powłoki przeciwzużyciowej TiBW na właściwości eksploatacyjne narzędzi skrawających do obróbki stopów niklu. Określono przy tym dynamikę zużycia narzędzia na podstawie zmian składowych całkowitej siły skrawania, obserwacji mikroskopowej zużycia na powierzchni przyłożenia oraz obserwację zużycia n podstawie obrazów SEM. Określono również stan technologicznej warstwy wierzchniej w postaci zmian morfologii mikrostruktury oraz utwardzenia warstwy przypowierzchniowej. Badania odniesiono do narzędzia referencyjnego o tej samej geometrii z powłoką AlTiN. Wykazano m.in., że powłoki TiBW mogą być z powodzeniem stosowane na narzędzia skrawające do obróbki stopów niklu a dynamiki zużycia jest podobna do narzędzi z powłoką AlTiN. Analizy potwierdziły istotne oddziaływanie termo-mechaniczne freza podczas obróbki objawiające się wykruszeniami oraz tendencją do umocnienia materiału obrabianego. Na podstawie obserwacji mikrostruktury warstwy wierzchniej po obróbce wykazano, że przewodność cieplna powłoki TiBW może być mniejsza niż w przypadku powłoki AlTiN, co objawia się w różnej głębokości stref oddziaływań termo-mechanicznych.

9

In-process monitoring of inhomogeneous material characteristics based on machine learning for future application in additive manufacturing

Jaquemod Andre, Palalic Marijana, Güzel Kamil, Möhring Hans-Christian

Journal of Machine Engineering

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2024

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Vol. 24, No. 2

83--93

EN

Additively manufactured components often show insufficient component quality due to the formation of different defects. Defects such as porosity result in material inhomogeneity and structural integrity issues. The integration of in-process monitoring in machining processes facilitates the identification of inhomogeneity characteristics in manufacturing, which is crucial for process adaptation. The incorporation of artificial defects in components has the potential to mimic and study the behaviour of real-world defects in a more controlled way. This study highlights the potential benefits of cutting force and vibration monitoring during machining operations with the goal of providing insights into the machining behaviours and the effects of the artificially introduced defects on the process. Detection of anomalies relies on identifying changes in force profiles or vibration patterns that might indicate the interaction between the tool and the defect. Machine learning algorithms were used to process and interpret the collected data. The algorithms are trained to recognize patterns, anomalies, or deviations from expected behaviours, which can aid in evaluating the effect of detected defects on the machining process and the resultant component quality. The main objective of this study is to contribute to enhancing quality control of machining processes for inhomogeneous materials.

10

A new grey box approach for friction modelling of machine tool drives

Rüppel Adrian Karl, Meurer Markus, Bergs Thomas

Journal of Machine Engineering

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2024

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Vol. 24, No. 1

5--16

EN

Measurement of the process force in milling is usually conducted by using piezo-electric dynamometers which are costly and reduce the stiffness of the system. A less invasive alternative is an indirect estimation of cutting forces based on the power of the servo drives. However, a correction of frictional effects from the transmission system is necessary to achieve accurate results. Most machine tools are equipped with ball-screw drives whose friction behavior is highly nonlinear due to dependency on both velocity and position. This study provides a novel approach to consider all frictional and inertial effects in transmission behavior of ball-screw drives by utilizing the well-established generalized MAXWELL slip (GMS) model and combines it with a data-based approach, namely support vector regression (SVR). The approach acquires the internal states of the GMS model and uses them as an additionnal input for the SVR. The model is validated on different experiments conducted on a five-axis machining center and compared to established friction models, as well as a sole SVR. The results show the model to have errors between 7% and 12% over the full working range of the x- and y-axes, respectively, outperforming the benchmark models significantly.

11

Hand drill shape optimization using Open CASCADE library and the steepest descent method

Król Roman

Archive of Mechanical Engineering

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2024

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LXXI, nr 3

375--398

EN

In this article, compliance optimization with the steepest descent method of the hand drill bits shapes for metal drilling is presented. The analysis of stress, displacements and compliance of the solid with random shape can be performed using the finite element method. In the case of a high number of optimization iterations, each analysis needs automatic modifications of geometry, mesh and boundary conditions. The Open CASCADE library can be used in the fast and automatic construction of modified models. It allows for fast reanalysis for each derivative of the objective function in the optimization process. The motivation of this research is to fill the gap in the literature on drilling technology. Most of the contemporary research is devoted to the oil and gas industry, while optimization of the hand drill bits used in metal drilling is rare. Compliance optimization allows us to find the shape which guarantees a greater stiffness for the specified loading conditions and a given amount of material. Although the obtained compliance was low, further experimental research would be needed to apply new solutions in drilling practice. This will involve the construction of the drill bit tips and the development of a heat treatment process.

12

SEC analysis of the molar mass of lignin isolated from poplar (Populus deltoides x maximowiczii) and Scots pine (Pinus sylvestris L.) wood

Skręta Aneta, Antczak Andrzej

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2024

|

No. 125

52--64

EN

SEC analysis of the molar mass of lignin isolated from poplar (Populus deltoides x maximowiczii) and Scots pine (Pinus sylvestris L.) wood. The aim of the study was to analyse the molar mass of lignin, which can be a waste product in bioethanol production technology. A studies of isolated lignin from two species: Populus deltoides x maximowiczii (hardwood) and Pinus sylvestris L. (softwood) were conducted to determine its molar mass using the SEC technique. Two acidic methods of lignin isolation were used during the studies. The use of 72% sulphuric acid yielded higher values of Mn, Mw and PDI and the lignin was better dissolved in 0.5% LiCl/DMAc system, which determined the continued use of this method in further studies. The Klason lignin samples for both species were subjected to milling at three time configurations: 5, 15 and 30 min, which resulted in an increase in the aforementioned values. The tests carried out and the analysis of the results indicated that milling times longer than 5 min caused degradation and repolymerisation of the lignin, as confirmed by the molar mass distributions. Some of the wood samples were pretreated with steam explosion and next isolated Klason lignin were milled. SEC analysis showed a decrease in Mn values with increasing milling time, while an increase in Mw and PDI for steam exploded poplar lignin. For analogical obtained steam exploded pine lignin, the values increased directly proportional. For the milling carried out, 5 min was recommended, so that lignin solubility increased and molar mass was determined more reliable.

PL

Celem badań była analiza masy cząsteczkowej ligniny, która może stanowić produkt odpadowy w technologii produkcji bioetanolu. Przeprowadzono badania wyodrębnionej ligniny z dwóch gatunków: Populus deltoides x maximowiczii (drewno liściaste) i Pinus sylvestris L. (drewno iglaste) w celu określenia jej masy cząsteczkowej techniką SEC. W badaniach zastosowano dwie kwasowe metody wyodrębniania ligniny. Zastosowanie 72% kwasu siarkowego pozwoliło uzyskać wyższe wartości Mn, Mw i PDI, a lignina lepiej rozpuszczała się w układzie 0,5% LiCl/DMAc, co determinowało kontynuację stosowania tej metody w dalszych badaniach. Próbki ligniny Klasona obu gatunków poddano mieleniu w trzech konfiguracjach czasowych: 5, 15 i 30 min, co spowodowało wzrost ww. wartości. Przeprowadzone badania i analiza wyników wykazały, że czasy mielenia dłuższe niż 5 min powodują degradację i repolimeryzację ligniny, co potwierdzają rozkłady mas cząsteczkowych. Część próbek drewna poddano wstępnej obróbce wybuchem pary, a następnie wyodrębnioną ligninę Klasona zmielono. Analiza SEC wykazała spadek wartości Mn wraz ze wzrostem czasu mielenia oraz wzrost Mw i PDI dla ligniny topolowej poddanej obróbce wstępnej wybuchem pary. Dla analogicznie otrzymanej ligniny sosnowej poddanej obróbce wstępnej wybuchem pary wartości wzrosły wprost proporcjonalnie. Dla przeprowadzonego mielenia zalecano czas 5 min i w ten sposób zwiększono rozpuszczalność ligniny, co umożliwiło w sposób bardziej wiarygodny określić jej masę cząsteczkową.

13

The Effect of Milling Parameters of Vanadis 4 Extra Steel on Cutting Force Values and Roughness of Machined Surface

Szajna Artur, Bazan Anna, Tymczyszyn Tymczyszyn, Kawalec Małgorzata, Rydzak Tomasz, Kubik Paweł

Advances in Science and Technology. Research Journal

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2024

|

Vol. 18, no. 8

181--190

EN

The article presents the results of experimental studies of the milling process of Vanadis 4 Extra - tool steel 1.2210 with a four-flute AlCrN-coated end mill. On the basis of the measured values of the total cutting force F and the roughness parameters Ra and Rz of machined surfaces, the relationships between specified cutting parameters and the analyzed roughness parameters were determined. Regression model of cutting force F was developed considering statistically significant cutting parameters. The developed model was validated using an additional set of recorded force values. Regression models were also created for the roughness parameters Ra and Rz of machined surfaces but they were found to be too inaccurate for the prediction of the aforementioned texture parameters. After analysis of the results obtained, it was found that the cutting speed vc had no effect on the value of the total cutting force F, while its influence on the roughness parameters was noticeable. It was also shown that, of the technological parameters ap, ae and fz within the assumed ranges of variation, the depth of cut ap, has the greatest effect on the cutting force F, the width of cut ae and the feed rate fz have a smaller effect. It was also shown that in the case of low cutting speeds vc the parameter Ra of the machined surface roughness strongly depends on the depth of cut ap and width of cut ae. At the same time it was noticed an increase in the Rz parameter with decreasing cutting speed vc. The remaining technological parameters, however, also significantly affect the obtained values of the Rz roughness parameter measured on the machined surface.

14

Simulation and Experimental Study of the Termo-Mechanical Effect of the Milling Process of 7075 Aluminium Alloy

Habrat W., Lisowicz Joanna, Tymczyszyn Jarosław, Skroban Anna

Advances in Science and Technology. Research Journal

|

2024

|

Vol. 18, no. 3

58--66

EN

This study combined simulation and experimental tests to analyse the cutting performance of three solid carbide end mills with distinct geometries during the milling of the 7075 aluminium alloy. For the tests, three uncoated end mills were employed, which differed in rake angle, clearance angle, and helical pitch. Simulation tests revealed temperature distributions and the resultant cutting forces. The machining with a milling cutter with a higher blade angle was shown to cause an increase in the temperature in the cutting zone. However, during machining with a sharper blade of cutting tool, a decrease of cutting forces was not observed. The simulated temperature distribution on the cutting edge of the cutting tool may justify significant differences in the dynamics of changes in the cutting force components during the period of operational wear.

15

Evaluation of Machinability Indicators in Milling of Thin-Walled Composite Structures

Ciecieląg Krzysztof

Advances in Science and Technology. Research Journal

|

2024

|

Vol. 18, no. 1

202--212

EN

Composite materials are alternative materials to aluminum and titanium alloys. The wide-spread use of this materials makes it necessary to gain insight into the phenomena occurring in machining processes for thin-walled structures. This paper shows the investigation of the machinability of thin-walled composite materials. The study involved milling glass and carbon reinforced plastics using tools dedicated to the processing of this type of material. Their machinability was determined based on the measured feed force, deformation and surface roughness. In addition, surface analysis was performed by SEM. The results showed that the feed had the greatest impact on the feed force, deformation and surface roughness, followed by cutting speed. Lower values of the measured machinability indicators such as the maximum feed force and roughness were obtained for composites with glass fibers. Lower deformations were induced in the machining of composites with carbon fibers. The study also involved conducting a recurrence analysis in order to select the most appropriate quantifications depending on the technological parameters of milling. It was found that the most appropriate indicators related with the technological parameters for both materials were laminarity and averaged diagonal length.

16

Effect of Cutting-Edge Geometry on the Machinability of 316L Austenitic Steel

Grabowski Marcin, Małek Marcin, Teimouri Reza, Skoczypiec Sebastian

Advances in Science and Technology. Research Journal

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2024

|

Vol. 18, no. 1

110--117

EN

The paper focuses on the problem of selecting the correct tool geometry in high-speed milling of 316L stainless steel. Carbide milling cutters with two configurations of helix angle (40/42 degrees for tool#1 and 35/38 degrees for tool#2) with different cutting edge radiuses rn (i.e. 4 µm, 6 µm, 8 µm, 10 µm and 12 µm) were prepared and their impact on cutting force and roughness were analyzed. The obtained results revealed that the small changes in cutting edge radius rn have a significant effect on both cutting forces and surface roughness. In this context, irrespective to the type of the tool, increasing the cutting edge radius results in further cutting force. However, increasing the cutting edge radius shows different behavior on roughness while using different tool helix angles. For the tool#1, it was found that the surface roughness increases by increasing the cutting edge radius from 6 μm to 12 μm; while in the samples machined by tool #2, increase in cutting edge radius results in reduction of roughness. It was also found that irrespective to the values of cutting edge radius, the cutting force while using tool #1 is slightly less than the tool#2. In addition, the induced milling surface roughness of the samples machined by tool#2 is significantly less than the tool#1 where the mean value of Ra was reduced from 2.55 µm to 0.35 µm

17

Selected aspects of the design of special monolithic carbide milling cutters for austenitic steels

Małek Marcin, Grabowski Marcin, Skoczypiec Sebastian

Technical Transactions

|

2023

|

Vol. 120, iss. 1

art. no. e2023017

EN

In many machining applications, the appropriate selection of cutting tools in relation to the type of material being machined, the machining parameters and the required shape and dimensional accuracy is of particular importance. This especially applies to operations requiring the use of specific tools, i.e. tools that are not included in the standard offer but are tailor-made according to the individual needs of the customer. The article focuses on the machining problems of selected austenitic grades of stainless steel and the selection of technologies (i.e. machining parameters and strategies and tool geometry) concerning the design and use of special monolithic carbide milling cutters. The possibilities of manufacturing elements from austenitic steels with high shape and dimensional accuracy and high surface layer quality are limited. Due to their high ductility, the tendency to create growths on the cutting edge and the high compression strength coefficient, these materials pose a serious technological challenge. The analysis of phenomena presented in the article forms the basis for developing guidelines for designing the machining process using special monolithic carbide cutters dedicated for specific applications.

18

Grindability characterization and work index determination of alluvial ferro-columbite deposits for efficient mineral processing

Nzeh Nnaemeka Stanislaus, Adeleke Abraham A., Popoola Patricia Abimbola

Physicochemical Problems of Mineral Processing

|

2023

|

Vol. 59, iss. 3

art. no. 170297

EN

This study emphasizes on the physicochemical and grindability characteristics and work index of an alluvial formed silica dominated ferro-columbite mineral from Rayfield-Jos minefields in Plateau state, Nigeria. Investigations were also carried out in order to determine the mineralogy of the mineral deposits and most essentially the actual energy consumed during comminution and milling of the mineral so as to achieve the liberation size prior to high efficient mineral processing or beneficiation and the extraction of value metals. The distribution of the mineral particles as well as their sizes was determined, with a mineral liberation size fraction range essentially established as -150+90 μm particle sizes. Mass percentage of each size fraction obtained from PSD analysis conducted before and after comminution was also determined, obtaining 80% passing for both the mineral feeds and comminuted products. Berry and Bruce modified Bond’s work index was therefore obtained, and was determined to be within the range of 2.0414 to 2.5667 kWh/ton. Hence, the energy consumed or required to comminute or grind the Fe-columbite mineral to 80% passing is expected to fall within the range of 0.3613 to 0.4543 kWh. Thus, it could be said that a low milling work index as well as moderately low energy is required for comminution and this can be attributed to the mineralogy, mineral source and alluvial formation of the mineral reserve. Therefore, the grindability/PSD result of the mineral sample indicates that its mineralogy is considered a class of moderately soft mineral type in terms of texture with easy grindability.

19

Flexure-based dynamometer for vector-valued milling force measurement

Ramsauer Christoph, Leitner David, Habersohn Christoph, Schmitz Tony, Yamazaki Kazuo, Bleicher Friedrich

Journal of Machine Engineering

|

2023

|

Vol. 23, No. 1

47--56

EN

Variation in cutting forces with cutting parameter selection, tool geometry, and wear status plays an important role for milling process evaluation and modeling. While piezoelectric force measurement is commercially available, it is often considered a precise but expensive method. This paper presents a novel solution for vector-valued cutting force measurement. The table-mounted, flexure-based kinematics provide three degrees of freedom that are used to measure the in-process milling force vector components in the working plane by low-cost optical sensors. Based on analytical models and FEM analysis, an appropriate design was derived. The assembly and testing of the developed dynamometer are presented. A test setup based on a machining center was used for the system evaluation and the data are compared to the forces measured by a commercially available, piezoelectric cutting force dynamometer.

20

Deep learning-based CNC milling tool wear stage estimation with multi-signal analysis

Karabacak Yunus Emre

Eksploatacja i Niezawodność

|

2023

|

Vol. 25, no. 3

art. no. 168082

EN

CNC milling machines are frequently used in the manufacturing of mechanical parts in the industry. One of the most important components of milling machines is the cutting tool. Monitoring the cutting tool wear is important for the reliability, continuity, and quality of production. Monitoring the tool and detecting the stage of wear are difficult processes. In this work, the convolutional neural network (CNN), which is a deep learning method in which the features are extracted by an inner process, was performed to detect the wear stages of the milling tool. These stages that define the total lifespan of the tool are known as initial wear (IW), steady-state wear (SSW), and accelerated wear (AW). Short Time Fourier Transform (STFT) was applied to signals, and signal spectrograms were used to train CNN models with different complex architectures. Vibration signals, acoustic emission signals, and motor current signals from The Nasa Ames Milling Dataset were used to obtain the spectrograms. Pre-trained CNNs (GoogleNet, AlexNet, ResNet-50, and EfficientNet-B0) detected the tool wear stage with varying accuracies. It has been seen that the time duration of model training increases as the size of the dataset grows and the network architecture becomes more complex. The recommended method has also been tested on the 2010 PHM Data Challenge Dataset. CNN shows promise for condition monitoring of milling operations and detecting tool wear stage.