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EN
Cutting tools made of the WC-Co sintered carbides are now very popular and are widely used in machining of materials. However, there are numerous problems in this area which require more research and need to be studied further. This paper presents the results of an experimental study aimed at discovering the impact of the microstructure, particularly of the tool substrate grain size, on the quality of the machined surface, cutting forces and temperature in the cutting zone, as well as the tool life. In addition, the impact of the feed was considered. The machining process involved side milling of a cuboidal block made of the AISI 316L steel which, due to its specific properties, is widely used in many industries. The tools used in the tests had different WC phase grain size: 0.18, 0.28 and 0.31 μm, respectively, and moreover the middle specimen had also a non-homogeneous structure and an increased content of the Co matrix. The tests proved a significant impact of the tool microstructure on the tool life and the roughness parameters Ra and Rz of the machined surface. The impact of the studied factors on the forces and the temperature in the cutting zone was not as strong, because it did not exceed 20%. The value and the novel character of the paper results from the fact that it concerns a specific case: side milling of the 316L steel with the use of the WC-Co sintered carbide tools, and consequently provides a contribution to solve a practical industrial issue.
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.
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.
4
Content available remote Optimization of micromachining operation for particle reinforced UHMWPE composites
EN
Unlike metals, polymers are highly affected by the heat generation during the machining of the workpiece, because the thermal conductivity of polymers are considerably lower than metals, and therefore heat is much more effective in the cutting zone. If the appropriate cutting parameters are not selected, the polymers become excessively deformed and the final part has high surface roughness, dimensionally large burr formation, or dimensional deviations. Machining of polymers ultra-high molecular weight polyethylene (UHMWPE) is quite common in industrial applications. In this study, the effect of SiC fillers on the machinability of UHMWPE polymer composite was investigated. First, different samples were produced using different filler sizes (1 μm, 50 μm, and 100 μm) and different filler amounts (1%, 3%, 5%). Micro-milling tests were carried out at a constant feed rate (70 mm/min), constant cutting depth (0.1 mm) and spindle speeds (1200, 2800, and 4400 rpm). Tool overhang lengths were selected as 10, 15, and 20 mm. During the experiments, the surface/burr shapes, cutting temperatures and cutting forces were observed. In general, it is observed that SiC filler reduces cutting forces and cutting temperatures. In the further stage of the study, Taguchi analysis was performed in the light of different SiC filler sizes, filler amounts, rotational speeds, and tool overhang lengths.
EN
This article shows the results of research on the effectiveness of operation of an original tool air cooling system in cutting. A case of turning EN-GJL 250 cast iron with TH10 tungsten carbide cutting inserts without protective coatings was selected for testing. The paper gives constructional details of the tested tool cooling system and discusses the principle of its operation. The research carried out has shown that this way of cooling the cutting insert causes a significant decrease in temperature in all sub-areas of the cutting zone. In addition, air cooling has been proven to significantly reduce cutting tool wear and slightly improve the roughness of the machined surface. The results obtained showed that the proposed method of cooling can be successfully used in the treatment of grey cast iron. In the future, it may serve as a basis for the construction of a professional cooling system for industrial applications.
EN
The study presents the influence of the anti-wear coatings and the type of material from which the cutting tools are made of on the cutting temperature occurring on the tool. The cutting tools made of boron nitride and tungsten carbide composite were investigated. The methodology of measuring the cutting temperature using the thermoelement and thermovision techniques was presented. The results of the temperature measurements occurring on the cutting tool in the cutting zone were compared. The paper also presents a method of determining the effective emissivity of the tested tools, necessary for the correct temperature measurement using the non-contact method. The obtained data were interpreted and the relationships described, and then the results obtained were discussed.
EN
This study presents an inverse heat transfer method to estimate the time history of a local heat flow into the work-piece during milling of AISIH13 with considering a 3D thermal model. Temperatures are measured using thermocouples within the work-piece providing input data for the inverse solver. The conjugate gradient method is used as an inverse solver to predict the local time dependent heat flow distribution on the cutting surfaces as well as the temperature distribution in the work-piece. A moving point heat source and a moving plane heat source with different heat source velocity is considered to investigate their influence on the estimated heat flow. Results indicate a good agreement between the experimental and estimated data with an average root mean square error less than 0.2 ◦C. It can be observed that the heat flow distribution is a function of heat source geometry, cutting speed and feed rate, but the temperature distribution is a weak function of geometry of the moving heat source. Changes of temperature with depth are studied. This study suggests that the developed inverse model can be successfully applied for estimating the heat flow and thermal field in the work-piece during milling.
8
Content available remote Reducing of process model uncertainty towards smart machining systems
EN
This paper presents an approach of empirical modeling of cutting process physical phenomena with measurement uncertainty parameters accompanied to the model exponents/ /coefficients. The approach is presented trough an example of creating a power mathematical model for average cutting temperature in turning with details about the uncertainty contributions from different experimental plans. The approach is proposed to be implemented as usual practice during empirical modeling, in order the resulting models to fit with the needs of the smart machining systems and the needs of interoperability between researchers.
PL
W pracy przedstawiono propozycję modelowania empirycznego zjawisk fizycznych w skrawaniu z uwzględnieniem parametrów niepewności pomiarowej oraz modelowych współczynników. Propozycję tę zaprezentowano na przykładzie modelu matematycznego temperatury skrawania, z podaniem danych dotyczących składowej niepewności z różnych planów eksperymentalnych. Postuluje się wdrożenie tego podejścia podczas modelowania empirycznego, tak aby otrzymane modele odpowiadały potrzebom inteligentnych systemów obróbki skrawaniem oraz potrzebom interoperacyjności między naukowcami.
EN
Research in 60s and 70s started to deal with the shape of the chip characterization. It was possible then to do a limited study by means of measuring tool park. During such a study, different models for chip formation became familiar, such as the Time or Merchant model. The aim of article is to gain insight into some accompanying phenomena, occurring while cutting of different materials and with various tools. During an experimental design, the possible effects of different variables on each other and individually were considered. Two work-pieces (C45, POM) with two inserts (with two different edge design) were tested while changing of cutting speed and feed. During measurements cutting forces at 5000 Hz signal reception were tested or the evolution of cutting temperature at different experimental settings was evaluated. The chip characteristics are measured by a high speed camera. The camera is connected with PC for recording and controlling the experimental procedure in real-time. The frequency of High Speed Camera was similar than the frequency of the cutting force measuring system. This similarity is provided with the system set-up synchronization.
PL
Przedstawiono dwie metody pomiaru temperatury podczas skrawania: metodę z wykorzystaniem termoelementu oraz termowizyjną. Opisano wpływ temperatury skrawania na intensywność zużycia narzędzi skrawających i ich trwałość. Zaprezentowano stanowisko pomiarowe, wykorzystane materiały i narzędzie skrawające. Zestawiono wyniki w postaci temperatury osiągniętej na ostrzu skrawającym przy zadanych parametrach obróbki podczas toczenia. Omówiono metody pomiaru temperatury ostrza za pomocą termoelementu oraz metodę radiacyjną – termowizję. Wyszczególniono zalety i wady każdej z metod.
EN
The paper presents a method of measuring the temperature during cutting and its impact on the machining process. The influence of temperature on the intensity of the cutting tool wear cutting and durability. Shows the measuring position, the materials used and the cutting tool. We present the results of the processing parameters, during which the measurements are made. This paper presents methods for measuring the temperature of the blade using a thermocouple and methods of radiation. It lists the advantages and disadvantages of each method.
EN
The heat produced in metal cutting process has negative influence on the cutting tool and the machined part in many aspects. This paper deals with measurement of cutting temperature during single-point dry machining of the AISI 4140 steel, using an infrared camera. Various combinations of cutting parameters, i.e. cutting speed, feed rate and depth of cut lead to different values of the measured cutting temperature. Analysis of the measured data should explain the trends in temperature changes depending on changes in the cutting regimes. Furthermore, the temperature data is modelled using response surface methodology and fuzzy logic. The models obtained should determine the influence of cutting regimes on cutting temperature. The main objective is the reduction of cutting temperature, i.e. enabling metal cutting process in optimum conditions.
PL
W artykule zaprezentowano badania dotyczące wyznaczania temperatury skrawania z wykorzystaniem pomiarów termowizyjnych. Tak określona temperatura skrawania posłużyła do doboru optymalnych warunków obróbki podczas toczenia stali stopowej 42CrMo4. Jako kryterium optymalizacyjne przyjęto jakość warstwy wierzchniej (twardość, chropowatość) oraz dokładność wymiarowo-kształtową wytwarzanego elementu. Przytoczono zalecenia dotyczące obróbki, których przestrzeganie zapewni spełnienie wymagań stawianych przez konstruktora.
EN
In the paper results of IR measurement of cutting temperature generated during turning process is presented. On the base of infrared sequences acquired during cutting tests the optimal cutting parameters have been established for 42CrMo4 alloy steel. As an optimalization criteria the quality of outer surface of the workpiece have been established. Hardness, surface roughness parameters and dimensional accuracy were measured to evaluate quality of outer surface of the machined parts. In order to meet constructional requirements for machined parts the recommendations and guides to properly conduct machining processes have been presented in the article.
PL
W artykule przedstawiono wyniki badań dotyczące toczenia wykończeniowego czopów wałów pomp okrętowych. Badania przeprowadzono na wałku ze stali nierdzewnej X5CrNi18-10 o średnicy 60 mm. Toczenie wykończeniowe wałów przeprowadzono na tokarce uniwersalnej CDS 6250 BX-1000. Proces skrawania wykonano przy użyciu wymiennych płytek wieloostrzowych firmy Sandvik Coromant. Do badań wykorzystano płytki dogładzające z technologią Wiper (WF). Podczas procesu toczenia zastosowano optymalne parametry skrawania dla płytek: CCMT 09T302 WF, CCMT 09T304 WF, CCMT 09T308 WF. Toczenie czopów wałów przeprowadzono dla kąta przystawienia równego 90° ± 3°. Do procesu toczenia wykorzystano siłomierz DKM 2010. Podczas badań określono wpływ geometrii noża tokarskiego na parametr chropowatości powierzchni Ra stali stosowanej na wały pomp okrętowych. Pomiary chropowatości powierzchni wykonano z wykorzystaniem profilometru T8000.
EN
The article presents the research results of pump shaft pins finish lathing. The research was performed on a roller 60 mm in diameter made of X5CrNi18-10 steel. The finish tooling of pump shaft pins was carry out on a universal CDS 6250 BX-1000 centre lathe. The finish lathing process was carried out by means of Sandvik Coromant cutting tool with replaceable inserts. In the research of lathing process used inserts with Wiper technology (WF). During the lathing the optimal machining parameters were used for inserts: CCMT 09T302 WF,CCMT 09T304 WF, CCMT 09T308 WF. The cutting process was performed at side angle of 90° ± 3°. The process of lathing used cutting tool dynamometer DKM 2010. During the research, the effect of cutting tool geometric on surface roughness parameter Ra of steel applied to marine pumps shaft pins was determined. Measurement of surface roughness parameters was performed by T8000 profilometer.
PL
Pompy krętne znalazły powszechne zastosowanie na statkach. W siłowniach okrętowych odśrodkowe pompy krętne stosowane są w obiegach chłodzenia silników średniej i dużej mocy, do zasilania kotłów oraz w instalacjach zęzowych, balastowych i przeciwpożarowych. Bardzo szerokie zastosowanie pomp krętnych na pokładzie związane jest z ich licznymi zaletami. Podczas eksploatacji wirowych pomp okrętowych dochodzi do zużycia kadłuba, wirnika, uszczelnień i wału. W artykule przedstawiono wyniki badań dotyczące toczenia wykończeniowego czopów wałów pomp okrętowych. Badania przeprowadzono na wałku ze stali nierdzewnej X5CrNi18-10 o średnicy 60 mm. Toczenie wykończeniowe wałów przeprowadzono na tokarce uniwersalnej CDS 6250 BX-1000. Proces skrawania wykonano przy użyciu wymiennych płytek wieloostrzowych firmy Sandvik Coromant. Do badań wykorzystano płytki standardowe (MF), płytki o zwiększonej dokładności wykonania (UM) oraz płytki dogładzające z technologią Wiper (WF). Podczas procesu toczenia zastosowano optymalne parametry skrawania. Toczenie czopów wałów przeprowadzono dla kąta przystawienia równego 90°. Do procesu toczenia wykorzystano siłomierz DKM 2010. Podczas badań określono wpływ geometrii noża tokarskiego i optymalnych parametrów skrawania na wartość sił i temperatury skrawania stali stosowanej na wały pomp okrętowych.
EN
Angular momentum pumps are very often applied onboard ships. These pumps are used in cooling circuits of medium and high power engines, power plant boilers and in bilge, ballast and firefighting installations. Very extensive use of angular momentum pumps on board is connected with their advantages. During operation the wear of marine hull, the rotor and shaft seals takes place. The article presents the research results of pump shaft pins finish lathing. The research was performed on a roller 60 mm in diameter made of X5CrNi18-10 steel. The finish tooling of pump shaft pins was carry out on a universal CDS 6250 BX-1000 centre lathe. The finish lathing process was carried out by means of Sandvik Coromant cutting tool with replaceable inserts. In the research of lathing process used standard inserts (MF), inserts with increased tolerance (UM) and inserts with Wiper technology (WF).During lathing the optimal machining parameters were used. The cutting process was performed at side angle of 90°. The process of lathing used cutting tool dynamometer DKM 2010. During the research, the effect of cutting tool geometric and optimal cutting parameter on the cutting forces and temperature ofsteel applied to marine pumps shaft pins was determined.
EN
The finite element method has been extensively used for the simulation of manufacturing processes and especially machining. In this paper, finite element models of high speed machining are presented. More specifically, orthogonal and oblique cutting models are presented, where the geometrical and material properties of the cutting tool are investigated. Orthogonal models pertain to the simulation of cutting with three different CBN tool types. Chip formation, cutting forces and temperatures are compared for each model, at the same cutting conditions. Additionally, 3D models are presented, where the back rake angle of the cutting tool is varied. From the results it may be concluded that 3D models provide more realistic results but they are computationally more demanding than 2D models. Finite element modelling of high speed machining can provide data for the process that would be either difficult or in some cases even impossible to obtain through extensive experimental work.
PL
W artykule określono oddziaływanie geometrii narzędzia na wyniki symulacji numerycznej skrawania z dużą prędkością. Przeprowadzono symulację numeryczną dla skrawania ortogonalnego 2D, dla trzech modeli narzędzi z CBN o różnej geometrii. Porównano podział modeli numerycznych narzędzi na elementy skończone oraz przedstawiono analizę procesu kształtowania wióra, wartości składowych siły skrawania, temperaturę w strefie skrawania oraz odkształcenie plastyczne w warstwie wierzchniej dla wybranych ich geometrii. Przeprowadzono również proces symulacji dla modelu skośnego 3D dla różnych wartości kąta pochylenia krawędzi skrawającej. Wyniki symulacji pozwoliły stwierdzić, że zastosowanie modeli 3D lepiej odzwierciedla rzeczywisty proces. Stawia jednak większe wymagania w zakresie obliczeń niż przy użyciu modeli 2D. Symulacja MES obróbki z dużą prędkością pozwoliła uzyskać wyniki, które mogą być trudne lub w niektórych przypadkach niemożliwe do uzyskania w ramach badań eksperymentalnych.
16
Content available remote Preliminary research of cutting forces of shaft pins
EN
One of the greatest problems of modern production techniques is the achievement of an appropriate quality at minimal costs and accompanied by the production efficiency increase. Therefore while designing the production process, the technology used should have a considerable influence on the durability and reliability of machine parts to be produced. During finish treatment the final dimensions as well as functional properties are imparted to a given element by application of proper treatment type. The engineer has a range of production techniques to choose for the proper surface layer formation. It is crucial to find a suitable solution which will meet the requirements as well as the work conditions of a given machine part. The paper presents the first stage of cutting forces tests which was research for shaft made of steel normal quality. A roller made of S235JR steel was used for the research. The process of sample surface finish lathing was performed by a cutting tool provided with CCMT 09T304 PF plates type. During the research, the effect of changes in the depth of cut on the value of cutting forces and temperature was defined.
PL
Jednym z najważniejszych problemów współczesnych technik wytwarzania jest zapewnienie odpowiedniej jakości wyrobu, przy minimalizacji kosztów i jednoczesnym wzroście wydajności produkcji. Dlatego podczas projektowania procesów wytwarzania powinno się zastosować technologię, która ma istotny wpływ na trwałość i niezawodność części maszyn. Podczas obróbki wykończeniowej nadawane są ostateczne wymiary i właściwości użytkowe danego elementu. Osiąga się to poprzez zastosowanie odpowiedniego rodzaju obróbki oraz dobór właściwych parametrów danego procesu. Technolog projektujący proces kształtowania warstwy wierzchniej ma do dyspozycji różne techniki wytwarzania. Konieczne jest znalezienie określonego rozwiązania, które będzie odpowiadać wymaganiom i warunkom pracy danej części maszyny. W artykule przedstawiono pierwszy etap badań pomiarów sił skrawania dla części typu wałek wykonany ze stali S235JR. Proces toczenia powierzchni próbki wykonano nożem z wymiennymi płytkami CCMT 09T304 PF. Na podstawie uzyskanych wyników badań określono wpływ parametrów skrawania na wartość sił skrawania oraz temperatury. Podczas eksperymentu analizowano wpływ głębokości skrawania przy stałej prędkości obrotowej oraz posuwie.
17
Content available Monitorowanie temperatury skrawania
PL
Artykuł niniejszy omawia przykłady praktyczne różnych sposobów monitorowania temperatury skrawania. Omawiane metody badawcze zilustrowano w oparciu o przypadek toczenia ortogonalnego na sucho stali austenitycznej AISI 321 ostrzami węglikowymi H10F bez- i z powłokami ochronnymi o różnej konfiguracji warstw. W artykule szczególną uwagę poświęcono metodzie termoelementu naturalnego w odmianie jednonożowej oraz pomiarom termowizyjnym. W podsumowaniu pokazano zalety i wady omawianych metod pomiaru temperatury skrawania.
EN
The paper discusses practical examples of different ways of monitoring the cutting temperature. These test methods are illus-trated based on the case of dry orthogonal turning of AISI 321 austenitic stainless steel by cemented carbide inserts H10F with and without protective coatings of varied layer configurations. In this paper particular attention is paid to the natural thermocouple in single-point cutting. Examples of application of the test method (Figs. 2 and 4) are shown, and measurement chain calibration is discussed (Figs. 5 and 6). Table 3 shows the results of the calibra-tion, i.e. the contact temperature as a function of the thermoelectrical force for selected tribological pairs of the tool-workpiece material. Moreover, the paper deals in detail with the methodology of the infrared imaging of the temperature distribution in the cutting zone. The considerations are based on the temperature distribution analysis on the top of the chip, which is directly in contact with the atmosphere (Fig. 10). Based on the literature data [2, 8] and the results of own research [3] an original method of calibrating the thermal imaging measurement chain was proposed (Fig. 7). This allowed determining the emissivity of the chip surface in settings similar to cutting conditions. In conclusion, there are presented the advantages and disadvantages of the discussed cutting temperature measurement methods by referring them to the literature results and the results of own research.
EN
One of the greatest problems of modern production techniques is the achievement of an appropriate quality at minimal costs and accompanied by the production efficiency increase. Therefore, while designing the production process, the technology used should have a considerable influence on the durability and reliability of machine parts to be produced. During finish treatment, the final dimensions as well as functional properties are imparted to a given element by application of proper treatment type. The engineer has a range of production techniques to choose for the proper surface layer formation. It is crucial to find a suitable solution which will meet the requirements as well as the work conditions of a given machine part. The article presents the preliminary research results referring to the analysis of the influence of finishing lathing on the cutting forces and surface roughness of steel. The research was performed on a roller 39 mm in diameter made of S235JR steel. The finish tooling of pump shaft pins was carrying out on a universal centre lathe. The finish lathing process was carried out by means of a CCMT 09T304 PF Sandvik Coromant cutting tool with replaceable inserts. During the research, the effect of changes in the depth of cut on the value of cutting forces and temperature was defined. In addition, the influence of the depth of cut on the surface roughness was determined.
EN
One of the greatest problems of modern production techniques is the achievement of an appropriate quality at minimal costs and accompanied by the production efficiency increase. Therefore while designing the production process, the technology used should have a considerable influence on the durability and reliability of machine parts to be produced. During finish treatment the final dimensions as well as functional properties are imparted to a given element by application of proper treatment type. The engineer has a range of production techniques to choose for the proper surface layer formation. It is crucial to find a suitable solution which will meet the requirements as well as the work conditions of a given machine part. The article presents the research results referring to the analysis of the influence of finishing lathing on the cutting forces and surface roughness of stainless steel. The research was performed on a roller 60 mm in diameter made of X5CrNi18-10 steel. The finish tooling of pump shaft pins was carry out on a universal CDS 6250 BX-1000 centre lathe. The finish lathing process was carried out by means of Sandvik Coromant cutting tool with replaceable inserts. During the research, the effect of cutting tool geometric on cutting forces and surface roughness of steel applied to marine pumps shaft pins ware tested. In addition, the influence of cutting tool geometric on cutting temperatures was determined.
PL
W artykule zaprezentowano wyniki badań eksperymentalnych dotyczących frezowania próbek ze stali 41Cr4 ulepszonej cieplnie i normalizowanej. W trakcie badań mierzono temperaturę w strefie skrawania oraz wyznaczano jej rozkład w obrabianym materiale. Do rejestracji temperatury zastosowano kamerę termowizyjną Flir SC6000HS. W kolejnym etapie badań mierzono naprężenia własne w obszarze temperatury generowanej w obrabianym przedmiocie. Badania naprężeń własnych wykonano metodą rentgenowską sin2Ψ. Na podstawie przeprowadzonych badań określono wpływ temperatury na wartości naprężeń własnych mierzonych w określonych miejscach rozlokowanych na obrabianym przedmiocie.
EN
In the paper experimental results concerning milling of 41Cr4 quenched and tempered and finally normalized steel are presented. During investigation distributions of temperature generated in the work material were measured. For acquisition of thermal sequences scientific infrared camera SC6000HS was used. In the second stage of investigation measurements of residual stresses generated in work material were done. For obtaining results concerning values of residual stresses in the specific positions located on the work piece, X-ray diffraction method sin2Ψ was employed. On the base of conducted tests and analyses, influence of temperature generated in the cutting zone on residual stress values measured in specific location on work specimens were investigated. Finally conclusions concerning obtained results were formulated.
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