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EN
The research used shafts made of X5CrNi18-10 (AISI 304L) stainless steel, which is used, among others in the shipbuilding industry. The turning process was carried out on the CU500MRD universal lathe with the use of cutting inserts with a corner radius of 0.2; 0.4 and 0.8 mm. The measurement of the forces during machining was recorded using a Kistler dynamometer. Surface roughness measurements were made with a Waveline W20 profilometer. The research results are the basis for determining the safe range of application of stainless steel cutting parameters on conventional lathes, with the simultaneous analysis of the quality of the machined surface.
PL
W badaniach wykorzystano wały wykonane ze stali nierdzewnej X5CrNi18-10 (AISI 304L), która znajduje zastosowanie między innymi w przemyśle okrętowym. Proces toczenia zrealizowano na tokarce uniwersalnej CU500MRD z wykorzystaniem płytek skrawających o promieniu naroża 0,2; 0,4 oraz 0,8 mm. Pomiar sił podczas obróbki skrawaniem rejestrowano z wykorzystaniem siłomierza firmy Kistler. Pomiary chropowatości powierzchni wykonano profilometrem Waveline W20. Wyniki badań są podstawą do wyznaczenia bezpiecznego zakresu stosowania parametrów skrawania stali nierdzewnej na tokarkach konwencjonalnych, przy jednoczesnej analizie jakości powierzchni obrobionej.
EN
Stainless steels have a wide usage field, their needs as structural parts are increasing day by day due to their resistance to corrosion and providing sufficient mechanical strength in environments that would cause corrosion. In addition to high mechanical properties of the stainless steels, the low heat transmission coefficients bring problems during machining. In this study, the suitable cutting tool and cutting parameters have been evaluated in terms of cutting forces and the tool temperature, the experimental results and finite element analysis have been compared in the milling of Custom 450 stainless steel which offers especially an excellent working opportunity at high temperature and salinity environment. Milling experiments have been carried out using L16 experimental design for Taguchi method. Four simulations have been made using finite element method with corresponding values in L16 orthogonal array for optimum cutting tool and the results were compared in terms of cutting forces and tool temperature changes.
EN
Computerized milling process is widely used in product manufacturing. Although manufacturing has gradually become highly-automated, the selection of machining conditions still remains an ever-present challenge in the process. To provide some findings contributable for the process planning, this study focuses on ball and filleted end milling. After brief explanations were given to the path interval determinations in both milling processes, the experiments were conducted to verify and characterize each procedure. The results of computational procedures showed good agreement with the experimental ones. Then, material removal rate and cutting force were analytically proposed for effective selection of machining conditions. The following findings were obtained from the demonstrations with discussion. Ball end milling required relatively large cutting force in the first tool path even though the material removal rate was comparatively small. On the contrary, filleted end mill enabled us to maintain a moderate cutting force in the first tool path even if the material removal rate expanded with increasing tool radius.
4
EN
Due to the wide application of Carbon Fiber Reinforced Polymer (CFRP) composites in various industries, more and more attention is paid to machining these materials. One of the most popular way of machining composites is the milling. Milling of composite materials (CM) is a difficult technology due to their anisotropic and heterogeneous structure and the fact that the reinforcing fibers have an intense abrasive effect on the tool edge during machining. The appropriate selection of technological cutting parameters as well as the type and geometry of the tool can significantly affect the value of cutting forces during milling and the quality of the surface after machining. The aim of the paper is to assess the influence of used tools (differing in the number of cutting edges) and various technological parameters of surface milling of CFRP composites on the cutting forces occurring during machining and on the surface quality after machining. Cutting forces were measured during the milling process on a special stand produced by Kistler and the roughness measurements and surface structure were analyzed using the Alicona InfiniteFocusG5 3D optical microscope. On the basis of performed research it was found that 14 edge tool gives lower values of Fx and Fy components of the cutting forces comparing to 2 edge tool, which is especially noticeable at higher cutting speed values vc=160 m/min, where the values of Fx and Fy components decreased by about 43% at fz=0.0030 mm/tooth. This tool gives also lower values of the Sa roughness parameter 1.65 µm.
PL
W artykule przedstawiono metodę optymalizacji topologicznej wybranych korpusów układu suportowego obrabiarki do kolejnictwa. Na przykładzie suwaka głównego przeprowadzono optymalizację topologiczną mającą na celu zredukowanie objętości obszarów biernych. Obliczenia numeryczne uwzględniają działanie sił skrawania, zapewniając dostateczną sztywność węzła.
EN
he article presents a method of topology optimisation of the selected carriage bodies of a railway machine tool. Based on the example of the main slider, topology optimization was performed to reduce the volume of passive areas. Numerical calculations take into account the action of cutting forces, which ensures a sufficient rigidity of the node.
EN
As an important research area of modern manufacturing, tool condition monitoring (TCM) has attracted much attention, especially artificial intelligence (AI)- based TCM method. However, the training samples obtained in practical experiments have the problem of sample missing and sample insufficiency. A numerical simulation- based TCM method is proposed to solve the above problem. First, a numerical model based on Johnson-Cook model is established, and the model parameters are optimized through orthogonal experiment technology, in which the KL divergence and cosine similarity are used as the evaluation indexes. Second, samples under various tool wear categories are obtained by the optimized numerical model above to provide missing samples not present in the practical experiments and expand sample size. The effectiveness of the proposed method is verified by its application in end milling TCM experiments. The results indicate the classification accuracies of four classifiers (SVM, RF, DT, and GRNN) can be improved significantly by the proposed TCM method.
EN
Effect of thermal modification temperature of spruce wood on cutting parameters during circular saw blade cutting. The work examines the effect of temperature on energetical parameters (specific cutting resistance and cutting force) when cutting heat-treated wood of Norway spruce (Picea Abies) by a circular saw. The test samples were heat-treated at 160°C, 180°C, 200°C and 220°C. One sample was not heat treated and was used as a reference sample. In comparison with the theoretical assumptions, the influence of temperature on the cutting force and specific cutting resistance was confirmed. With increasing temperature of modification, the specific cutting resistance and cutting force decreased. The reduction of value of cutting force is related to changes in the chemical structure of the wood components, weight and density loss due to the increasing temperature of modification.
PL
Wpływ temperatury modyfikacji termicznej drewna świerkowego na parametry skrawania podczas cięcia piłą tarczową. W pracy zbadano wpływ temperatury modyfikacji na parametry skrawania (oprór skrawania i siła skrawania) przy cięciu piłą tarczową drewna świerka pospolitego (Picea Abies) poddanego obróbce termicznej. Próbki drewna do badań poddano obróbce w temperaturze 160°C, 180°C, 200°C i 220°C. Jako wariant kontrolny wykorzystano drewno naturalne (nie poddane obróbce termicznej). W ramach badan potwierdzono wpływ temperatury modyfikacji na siłę skrawania i opory skrawania drewna. Wraz ze wzrostem temperatury modyfikacji zmniejszały się wartosci oporu skrawania i siły skrawania. Zmniejszenie wartości siły skrawania związane jest ze zmianami struktury chemicznej składników drewna, ubytkiem masy i gęstości pod wpływem wzrostu temperatury modyfikacji.
EN
Turning machining is a complex process in which many variables can influence the desired results. Among those variables, cutting tool vibration and cutting force greatly affect the precision of the workpiece and the tool life. While the tool vibration and cutting force in feeding are primarily determined by cutting speed, feed rate, and depth of cut as well as the dynamic characteristics of the machining system. This paper presents an analytical modeling approach to investigate the effects of machining conditions based on the governing equation of the machining system. The machining behaviors under different conditions were simulated by Simulink block diagram. Basically, the cutting speed is considered the parameter dominating the vibration behavior and hence is served as the primary input for the simulation. The effectiveness of constant surface speed (CSS mode) or function G96 in the turning process was further examined through comparisons of the variations of vibration and cutting force generated in feeding with different conditions.
PL
W artykule zaprezentowano wpływ wartości parametrów modelu konstytutywnego Johnsona–Cooka na wyniki symulacji MES procesu toczenia. W symulacjach użyte zostały cztery dostępne w literaturze zestawy parametrów modelu J–C dla stopu tytanu Ti6Al4V. Wyniki symulacji zostały porównane pod kątem otrzymanych wartości siły skrawania, rozkładu naprężeń oraz postaci wióra. Odnotowano znaczący wpływ wartości parametrów modelu J–C na wyniki symulacji.
XX
The article presents the effect of different sets of Johnson–Cook constitutive model parameters on the results of an FEM turning process simulation. Four different sets of parameters available for Ti6Al4V titanium alloy taken from open literature were used. Simulation results were compared on the account of cutting force, stress distribution and chip shape. The research has shown a substantial effect of J–C model parameter values on simulation results.
10
Content available Monitorowanie sił skrawania podczas toczenia
EN
It is well known that machining is the basic technique for manufacturing machine parts. Over the years, the machining processes have intensified, and what is more, the machining of difficult-to-cut materials, such as nickel and titanium alloys, has become more and more popular. For this reason, the process of cutting is not fully understood. Therefore, knowledge of the distribution of cutting forces and phenomena occurring in the cutting zone allows, for example, for optimization of cutting parameters and monitoring of tool wear. In the literature, the measuring devices for the total cutting force components were rarely described. For this reason, the authors have decided to explore the subject in greater depth. This article presents examples of constructions of turning actuators and comparison of results obtained for strain gauges of own design and professional piezoelectric actuator for the same machining parameters.
PL
Powszechnie wiadomo, że obróbka skrawaniem jest podstawową techniką wytwarzania części maszyn. Z biegiem lat zauważalna jest intensyfikacja procesów obróbki, co więcej – coraz częściej obrabiane są materiały trudnoskrawalne, np. stopy niklu i tytanu. Z tego powodu proces ich skrawania nie do końca jest poznany. Znajomość rozkładu sił skrawania i zjawisk występujących w strefie skrawania pozwala np. na optymalizację parametrów skrawania oraz na monitorowanie zużycia narzędzia. W literaturze fachowej urządzenia do pomiaru składowych całkowitej siły skrawania były rzadko opisywane. Z tego powodu autorzy postanowili zgłębić ten temat. Artykuł niniejszy przedstawia przykładowe konstrukcje siłomierzy tokarskich oraz porównanie wyników uzyskanych dla siłomierzy tensometrycznych własnej konstrukcji i profesjonalnego siłomierza piezoelektrycznego dla tych samych parametrów obróbki.
PL
Przeanalizowano wpływ wybranych parametrów skrawania (prędkości i posuwu) na moment i siłę skrawania podczas wiercenia żeliwa EN-GJL-250. Operacja wiercenia została wykonana wiertłem składanym firmy Allied Machine z serii DEM22000S-20FM, na pionowym centrum frezarskim Hermle B300. Pomiar momentu i siły skrawania podczas wiercenia przeprowadzono siłomierzem firmy Kistler.
EN
The impact of selected cutting parameters (cutting speed and cutting feed) on the torque and cutting force during drilling gray cast iron EN-GJL-250 was analyzed. The drilling operation was carried out by Allied Machnie drill series: DEM22000S-20FM, on the Hermle B300 vertical milling center. The measurement of the torque and the cutting forces during drilling was carried out by Kistler device.
12
PL
Przedstawiono ocenę wyników badań eksperymentalnych przydatną do wyznaczania minimalnej grubości warstwy skrawanej podczas obróbki narzędziami jednoostrzowymi o zdefiniowanej geometrii. Po przeprowadzeniu badań dla kilku materiałów skrawanych i gatunków materiałów narzędziowych opracowano równania ekstrapolacji z zachowaniem stałej temperatury skrawania. Czynniki zakłócające mechanizm oddzielania, wpływające na pomiary składowych siły i temperatury skrawania, zależą od materiału skrawanego i zastosowanego narzędzia.
EN
The article presents an evaluation of the results of experimental tests useful for determining the minimum thickness of cut during machining of single-point tools of defined geometry. After completing the tests for several cut materials and types of tool materials, extrapolation equations were developed while maintaining constant temperature. Factors interfering with the mechanism of separation, influencing the measurements of the components of the cutting force and the cutting temperature depend on the cut material and the material of the tool.
PL
Przeanalizowano siły skrawania w procesie obróbki obwodowej frezem stożkowym. Badania przeprowadzono dla różnych kątów skręcenia powierzchni obrabianej oraz różnych wartości kąta prowadzenia narzędzia.
EN
Presented is the analysis of the cutting force in the flank milling process with a conical mill. The tests were carried out for various twist angles of the machined surface and different values of the lead angle.
14
Content available remote Badania symulacyjne siły skrawania w procesie obróbki frezem baryłkowym
PL
Przedstawiono badania symulacyjne przebiegu siły skrawania w procesie obróbki frezem baryłkowym. Analizy przeprowadzono na modelach powierzchni wklęsłych oraz wypukłych o różnych promieniach krzywizny.
EN
The paper presents simulation tests of cutting force in the process of barrel milling. The analyzes were carried out on concave and convex surfaces with different radii of curvature.
EN
The paper presents the results of researches of temperature variations during flat peripheral grinding. It is shown that the temperature variations of the workpiece can reach 25...30% of the average values, which can lead to some thermal defects. A nonlinear two-dimensional thermophysical grinding model is suggested. It takes into account local changes in the cutting conditions: the fluctuation of the cut layer and the cutting force, the thermal impact of the cutting grains, and the presence of surface cavities in the intermittent wheel. For the numerical solution of the problem, the method of finite differences is adapted. Researches of the method stability and convergence are made, taking into account the specific nature of the problem. A high accuracy of the approximation of the boundary conditions and the nonlinear heat equation is provided. An experimental verification of the proposed thermophysical model was carried out with the use of installation for simultaneous measurement of the grinding force and temperature. It is shown that the discrepancy between the theoretical and experimental values of the grinding temperature does not exceed 5%. The proposed ther-mophysical model makes it possible to predict with high accuracy the temperature variations during grinding by the wheel periphery.
EN
In the paper, the experimental investigations related with longitudinal turning of Ti-6Al-4V ELI alloy (Grade 23) typically used in aeronautics industry have been presented. The main goal was to determinate the influence of changes in a selected cutting parameters (vc and f) for total cutting force Fc and its components. In this case, the analysis of the components of cutting force Fc measured during workshop experimental investigations was carried out. Next, the measured values were compared with the values calculated on the basis of formulas available in the literature. This allowed one to state that universal theoretical formulas can also be used to determine the components of the total cutting force F in the longitudinal turning process of Ti-6Al-4V ELI alloy.
EN
The article presents the results of studies on the dynamics of wear of five different cutting inserts (for machining difficult-to-cut materials, for finishing cast iron machining, for roughing cast iron machining, for steel machining and for stainless steel machining) during turning a non-homogeneous material such as polymer concrete. Polymer concrete is a difficult-to-cut, anisotropic, composite material. During the tests, a record of the components of the cutting force in real time was made. After each machining pass, the Ra and Rz surface roughness values were measured in the direction perpendicular to the machining marks and photos were taken under the microscope of the inserts corners, on the basis of which the width of major flank wear land and the width of minor flank wear land were measured. The view of each insert after the tests was also presented. Finally, the conclusions about the dynamics of wear of inserts taking part in the study as well as their applicability during polymer concrete turning were formulated.
PL
W niniejszym artykule zaprezentowano wyniki badań dynamiki zużycia pięciu różnych płytek skrawających (do obróbki materiałów trudnoobrabialnych, do wykończeniowej obróbki żeliwa, do zgrubnej obróbki żeliwa, do obróbki stali oraz do obróbki stali nierdzewnej) podczas toczenia niejednorodnego materiału, jakim jest polimerobeton. Polimerobeton jest trudnoobrabialnym, anizotropowym materiałem kompozytowym. Podczas wykonywania badań dokonywany był zapis składowych siły skrawania w czasie rzeczywistym. Po wykonaniu każdego przejścia obróbczego zostały zmierzone wartości parametrów chropowatości Ra oraz Rz obrobionej powierzchni w kierunku prostopadłym do śladów obróbki oraz zostały wykonane zdjęcia pod mikroskopem naroży płytek, na podstawie których zmierzono zużycie głównej powierzchni przyłożenia oraz pomocniczej powierzchni przyłożenia. Zaprezentowano również wygląd każdej z płytek po przeprowadzonych badaniach. Na koniec sformułowano wnioski na temat dynamiki zużycia płytek biorących udział w badaniu, a także stosowalności ich podczas toczenia polimerobetonu.
EN
In this article, a novel approach to computer optimization of CNC toolpaths by adjustment of cutting speed vcand depth of cut apis presented. Available software works by the principle of adjusting feed rate on the basis of calculations and numerical simulation of the machining process. The authors wish to expand upon this approach by proposing toolpath optimization by altering two other basic process parameters. Intricacies and problems related totheadjustment of apand vcwere explained in the introductory part. Simulation of different variant of the same turning process with different parameter values were conducted to evaluate the effect of changes in depth of cut and cutting speed on process performance. Obtained results were investigated on the account of cutting force and tool life. The authors have found that depth of cut substantially affects cutting force, while the effect of cutting speed on it is minimal. An increase in both depth of cut and cutting speed affects tool life negatively, although the impact of cutting speed is much more severe. An increase in depth of cut allows for a more significant reduction of machining time, while affecting tool life less negatively. On the other hand, the adjustment of cutting speed helpsto reduce machining time without increasing cutting force component values and spindle load.
EN
The present paper presents comparative results of the forecasting of a cutting tool wear with the application of different methods of diagnostic deduction based on the measurement of cutting force components. The research was carried out during the milling of the Duralcan F3S.10S aluminum-ceramic composite. Prediction of the tool wear was based on one variable, two variables regression, Multilayer Perceptron (MLP) and Radial Basis Function (RBF) neural networks. Forecasting the condition of the cutting tool on the basis of cutting forces has yielded very satisfactory results.
PL
Zjawisko formowania się zadziorów jest nieodzownym elementem procesu skrawania. Narzędziami przeznaczonymi do usuwania zadziorów są szczotki z włóknami ceramicznymi. Istnieje wiele czynników zmiennych związanych z konstrukcją szczotek ceramicznych, które dobiera się w zależności od rodzaju materiału obrabianego, wielkości zadziorów i spodziewanych efektów obróbki. Do czynników zmiennych zalicza się: rodzaj włókna ceramicznego, wartość wysunięcia włókien z tulei korpusu, sztywność sprężyny uchwytu kompensacyjnego. Poza zmiennymi wynikającymi z konstrukcji szczotek, podczas procesu można dodatkowo sterować parametrami technologicznymi (prędkość posuwu, prędkość skrawania i dosuw). W pracy analizowano wpływ wybranych czynników konstrukcyjnych szczotek ceramicznych na siłę osiową w procesie szczotkowania. Do badań użyto próbek prostopadłościennych wykonanych ze stopu aluminium 7075. Badania przeprowadzono na autorskim siłomierzu tensometrycznym o częstotliwości próbkowania 80 Hz. Szczotkowano płaską powierzchnię próbek ustawioną prostopadle do osi narzędzia. Wykazano, że dla ustalonych w eksperymencie warunków procesu w większym stopniu na wartość siły osiowej wpływa rodzaj zastosowanej sprężyny w uchwycie kompensacyjnym niż rodzaj zastosowanego włókna.
EN
The formation of burrs is an inevitable part of the cutting process. Dedicated tools for deburring are brushes with ceramic fibres. There are many variable factors relating to the construction of ceramic brushes, which are selected depending on the type of the workpiece, the size of burrs and the expected machining effects. Variable factors include the type of ceramic fibre, projection of ceramic fibre from sleeve, the spring stiffness of the floating holder. In addition to variables related to the construction of the brushes, the process parameters (feed rate, cutting speed and depth of cut) can be controlled during the process. The article analyzes the influence of selected ceramic brush construction factors on the axial force in the brushing process. Cuboid samples made of 7075 aluminium alloy were used during the studies. The tests were carried out on a strain gauge with a sampling frequency of 80 Hz. Flat surfaces of specimens perpendicular to the tool axis were subjected to brushing. It has been shown that the type of spring used in the floating holder has a greater effect on the value of axial force than the type of fibre used.
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