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EN
In machining applications predominantly for automated machining cells, tool life is often not used to its full extend and cutting tools are exchanged prematurely to avoid tool breakage and thus machine downtime or even damage at work piece or machine. Both effective process monitoring and adequate process control require reliable data from sensors and derived indicators that enable meaningful evaluation. Acceleration measurement by the instrumented tool holder provides signals with high quality from close to the cutting zone. Using the monitoring system, the gained data of the instrumented tool holder can be analyzed especially for the use case of unexpected tool wear, chipping of the cutting edge or breakouts at end mills. This paper describes the data analysis based on the rotational sensor and the corresponding effects on the measurement, an advanced assessment of the spectral distribution in the frequency domain and the experimental results of a test series.
EN
This paper highlights tool wear mechanisms in the machining of heat resistance alloys including nickel-based Inconel 718 alloy which is one of the most popular material in the aircraft industry. Special attention was paid to the notch wear which develops on the flank face due to high temperature oxidation of the cutting tool material at temperature of about 800°C. The experimental procedure includes the diffusion couple methods and tool wear tests which assess the degradation of the deposited coating. The obtained results were supported by SEM images of the flank face periphery and EDS analysis performed in the regions of intensive oxidation. Some conclusions and ongoing research on the investigation of the oxidation phenomenon of cutting tool materials are outlined.
PL
Zaproponowano sposób obliczeniowego oszacowania wpływu zużycia narzędzi skrawających na intensywność zużywania korozyjnego warstwy wierzchniej materiału obrabianego. Cechą charakterystyczną podejścia jest ocena stopnia zużycia korozyjnego w zależności od zużycia narzędzia, parametrów chropowatości powierzchni przedmiotu obrabianego i stopnia utwardzania warstwy wierzchniej na zimno, a także parametrów warunków obróbki technologicznej (parametrów skrawania, geometrii narzędzia skrawającego, właściwości obrabianego materiału i narzędzia).
EN
A possible variant for calculated estimation of the degree of the impact of the cutting tool wear on the value of the part’s surface layer wear obtained during processing with the edge tool, due to atmospheric corrosion, is presented. The feature is the evaluation of the wear rate and its numerical value depending on the tool wear, roughness parameters of the work piece surface, and the degree of cold hardening of the surface layer, as well as parameters of the technological machining conditions (cutting conditions, geometry of the tool cutting part, properties of the machined and the tool materials).
EN
During of hypereutectic Al-Si alloys, tool wear increases owing to the presence of silicon particles. Therefore, polycrystalline diamond tools are typically used, but they are very expensive. The purpose of this study is to examine the tool wear characteristics during the end milling of hypereutectic Al-Si alloy (A390–T6) by using comparatively inexpensive diamond-like carbon coated cemented carbide tools. Al-Si alloy was end-milled by changing the cutting speed. Our results revealed that the width of flank wear land increased monotonously with increasing of the cutting force regardless of the cutting speed. In addition, the experimental equation of the width of flank wear land was derived as a function of cutting speed and time, and it was clarified that width of flank wear land could be approximated.
5
EN
Knowledge of the tool wear state in machining has become an important issue in research and industrial application. Current systems use the spindle power or cutting force as measured variable and refer it to a taught set point. However, this method lacks the ability to adapt to new work piece geometries. A new approach focusses on the tool instead of the work piece, and uses a sensory tool holder with integrated strain gauges. This tool holder provides polar figures whose shapes relate to the engagement conditions and whose area is a function of the tool load. As the tool load increases with tool wear, the area of the polar figures provides information about the tool wear status, and with knowledge about the engagement conditions, the model can be calibrated.
EN
The effect of the cutting fluid with zinc aspartate on the quality of the workpiece surface layer is reported. Until now, zinc aspartate has been used primarily in medicine and pharmacology. This paper compares the ecological cutting fluid containing zinc aspartate with a classic mineral oil-based coolant. Toxicity tests and a controlled process of tool wear during face turning were performed. Test results indicate that the use of zinc aspartate-based cutting fluids contributes to the reduction of the material roughness parameter values up to 35%, benefitting the final quality of the workpiece.
PL
W pracy przedstawiono wyniki badań wpływu cieczy chłodząco-smarującej z asparaginianem cynku na jakość technologiczną warstwy wierzchniej obrabianych elementów. Asparaginian cynku dotychczas nie był stosowany w takich rozwiązaniach, głównie wykorzystywany był w medycynie i farmakologii. W badaniach przeprowadzono analizę porównawczą proekologicznego chłodziwa zawierającego asparaginian cynku z klasycznym chłodziwem opartym na bazie oleju mineralnego. Ciecze chłodząco-smarujące poddano badaniom toksyczności oraz wykonano kontrolowany proces eksploatacji narzędzi w czasie toczenia poprzecznego. Wyniki badań wskazują, że zastosowanie chłodzenia cieczą na bazie asparaginianu cynku redukuje parametry chropowatości obrabianego materiału nawet o 35%, korzystnie wpływając na jakość finalną detalu.
EN
Additive Manufacturing (AM) technologies are increasingly applied in various industries since they provide the possibility to manufacture the components with high geometrical complexity easier and faster than traditional processes. However, the subsequent semi-finish/finish machining operations such as drilling, turning and/or milling are still necessary for AM parts to obtain the required surface textures and meet the practical requirements. As such, the AM parts usually indicate different machinability compared with conventionally produced ones in view of the different material microstructures. A comprehensive understanding of this machining effort is of great importance for similar engineering applications but not widely reported. Thus, an attempt was made in this work to address the effect of the material microstructure on the machining stability and tool wear behavior in dry drilling of the hard titanium alloys. The experimental results highlight a correlation between the tool wear behavior and material microstructures. A great number of micro-pits appeared on the tool flank face and the abrasive marks, coating delamination, as well as catastrophic failure of the cutting edge were found to be more obvious during machining the DMLS alloy. In contrast, adhesion wear followed by micro chipping and build-up edge were distinguished when machining the wrought Ti6Al4V. Meanwhile, heat treatment can improve the flow plasticity and reduce the brittleness of the AM material since catastrophic failure disappeared and chip adhesion becomes more predominant when machining the HTDMLS Ti6Al4V.
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.
PL
W artykule przedstawiono wyniki badań dotyczących wpływu obecności powłoki TiN na ostrzach mikrowierteł w procesie mikrowiercenia tworzywa kompozytowego na ich zużycie i trwałość, a także na jakość wykonywanych otworów. Do oceny zużycia i trwałości ostrza mikrowierteł posłużono się wskaźnikiem zużycia naroża ostrza, pomiarem osiowej siły skrawania oraz sumaryczną długością wiercenia. Jakość wykonywanych otworów oceniano natomiast na podstawie obrazów mikroskopowych krawędzi otworów od strony wejścia i wyjścia wiertła. Stwierdzono wyraźne różnice w efektach stosowania porównywanych narzędzi.
EN
In this paper the results of investigations concerning the influence of TiN coating on the edges of microdrills on their wear and durability, as well as on the quality of made holes in the process of microdrilling of composite material were presented. To evaluate the wear and durability of microdrills' edges, the index of edge corner wear, the measurement of axial cutting force and drilling length were used. The quality of drilled holes was evaluatedon the basis of microscopic images of the contour of holes on the entry and exit side of the drill. Significant differences were found in the effect of using the compared tools.
10
Content available remote Optimization of Inconel 718 milling strategies
EN
This paper applies to the tests of the machining of a part made of supper alloy – nickel alloy – Inconel 718, using a monolithic carbide cutter. The paper includes a different versions of cutting methods with variable cutting parameters and machining strategies. The used sustainable machining process allowed to obtain control over the tool wear.
PL
Artykuł dotyczy badań obróbki ubytkowej części wykonanej ze stopu na osnowie z niklu – Inconel 718, z zastosowaniem monolitycznego frezu z węglików spiekanych. Przedstawiono różne metody obróbki części przy zmiennych parametrach skrawania oraz strategiach. Zastosowano zrównoważony proces obróbki, który pozwolił uzyskać kontrolę nad zużyciem narzędzi skrawających.
EN
This paper highlights the performance of precision hard turning with CBN cutting tools from energy point-of-view with additional tool wear effect. For this purpose several wear tests were performed during which the tool nose wear VBC and the corresponding changes of component forces Fc, Ff and Fp were continuously measured. Based on the measured forces and geometrical characteristic of the uncut layer, specific cutting and ploughing energy were determined for several combinations of cutting parameters. Consequently, changes of energy consumption resulting from tool wear evolution for variable feed rate, depth of cut and tool nose radius were presented.
EN
This paper presents a multi-factorial approach to the tool wear evolution when machining Ti6Al4V titanium alloy using high temperature resistant AlTiN coated cutting tools. Machining conditions were selected based on the technological database of machining titanium alloys in aircraft plants. The main novelty of this study is that tool wear progress within the tool life of about 20 min is assessed integrally in terms of mechanical, thermal and tribological process outputs such as cutting forces, cutting energy and cutting temperature. Moreover, the specific cutting energy (SCE), thermal softening effect and friction coefficient (CoF) were determined when recording tool wear curves. Some important research findings concerns distinguishing the three characteristic wear periods with distinctly different values of SCE and CoF. In particular, it was revealed that the formation of ceramic protective layer (CPL) on the AlTiN deposited coating influences friction and the tool wear mechanism.
PL
W artykule przedstawiono wieloczynnikowe podejście do ewolucji zużycia narzędzi podczas obróbki stopu tytanu Ti6Al4V przy użyciu narzędzi skrawających powlekanych, odporną na wysoką temperaturę, powłoką narzędziową AlTiN. Warunki obróbki zostały ustalone w oparciu o technologiczną bazę obróbki stopów tytanu stosowaną w przemyśle lotniczym. Główną nowością w ocenie przedstawionych badań jest to, że postęp zużycia narzędzia w okresie jego trwałości rzędu 20 minut jest oceniany integralnie, głównie pod względem mechanicznych, termicznych i trybologicznych efektów procesu skrawania, takich jak siły skrawania, energia i temperatura skrawania. Ponadto wyznaczono, adekwatne do zarejestrowanych krzywych zużycia narzędzia, wartości energii właściwej skrawania (EWS), zmiękczenia termicznego i współczynnika tarcia (WT). Niektóre ważne ustalenia badawcze dotyczą rozróżnienia trzech charakterystycznych okresów zużycia z wyraźnie różnymi wartościami EWS i WT. W szczególności okazało się, że utworzenie ceramicznej warstwy ochronnej (CWO) na narzędziowej powłoce z AlTiN wpływa na tarcie i mechanizm zużycia narzędzia.
EN
In hot forging process, tool life is an important factor which influences the economy of production. Wear mechanisms in these processes are dependent on each other, so modeling of them is a difficult problem. The present research is focused on development of a hybrid tool wear model for hot forging processes and evaluation of adding adhesive mechanism component to this model. Although adhesive wear is dominant in cases, in which sliding distances are large, there is a group of hot forging processes, in which adhesion is an important factor in specific tool parts. In the paper, a proposed hybrid tool wear model has been described and various adhesive wear models have been reviewed. The feasible model has been chosen, adapted and implemented. It has been shown that adding adhesive wear model increases predictive capabilities of the global hybrid tool wear model as far as characteristic hot forging processes is considered.
PL
W artykule przedstawiono wyniki badań wpływu prędkości skrawania, z uwzględnieniem zakresu prędkości o podwyższonych wartościach, narzędziami składanymi na moment skrawania oraz siłę bierną w procesie frezowania stopu tytanu Ti6Al4V. Eksperyment przeprowadzono na pionowym centrum obróbkowym Avia VMC800HS. Do badań wykorzystano siłomierz Kistler 9125A. Wykazano znaczący wpływ wartości zużycia ostrza i prędkości skrawania na wartość siły biernej i momentu skrawania.
EN
The paper reports the results of the study investigating the effect of cutting speed, including a range of increased speed values, on the cutting torque and axial force in the milling of Ti6Al4V titanium alloy. The experiment was performed on the Avia VMC800HS vertical machining center and the 9125A Kistler dynamometer was used in the tests. The results demonstrate that the degree of tool wear and the applied cutting speed have a significant effect on the value of axial force and cutting torque.
PL
Przedstawiono wyniki badań wpływu zużycia ostrza na moment skrawania oraz siłę bierną podczas frezowania stopu tytanu Ti6Al4V. Do badań wybrano płytki skrawające o różnym stopniu zużycia. Widoczny jest wpływ wartości zużycia na powierzchni przyłożenia oraz prędkości skrawania na wartość siły biernej i momentu skrawania.
EN
The results of the survey on the influence of tool wear on the cutting torque and axial force in the milling of Ti6Al4V titanium alloy are presented. The tests were carried out by selecting cutting inserts with different degree of wear. The influence of the wear value on the flank surface and the cutting speed on the value of axial force and cutting torque is visible.
16
Content available remote Wpływ tlenu na zużycie ostrza w obróbce skrawaniem
PL
Wysoka temperatura w strefie skrawania sprzyja utlenianiu, które jest jednym z mechanizmów zużycia ostrza obok ścierania, adhezji i dyfuzji. Aby zbadać udział utleniania w zużyciu ostrza, trzeba zbudować komorę zapewniającą kontrolowaną atmosferę otaczającą ostrze.
17
Content available remote Analiza mechanizmów zużycia ostrzy piły tarczowej
PL
Przedstawiono wyniki badania zużycia ostrzy piły tarczowej w próbach przecinania różnych gatunków stali w warunkach przemysłowych. Próby przeprowadzono na centrum obróbkowym CNC BLM EM 80. Analizie poddano zużycie ostrza podczas przecinania stali C35EC, Pb-30, 16MnCrSPb5 i S355J2+C. Narzędzie (piłę tarczową) mierzono przed obróbką wybranych gatunków stali i po niej. Określono zużycie ostrzy oraz ich podatność na wyłamania.
EN
The work is devoted to the machinability problems of selected grades of steel in the conditions of cutting rods with a circular saw. Selected indicators of machinability of steels were tested in industrial conditions. Attempts to cut steel were carried out on a BLM EM 80 CNC machining center. The analysis covered the tool wear during cutting of C35EC, Pb-30, 16MnCrSPb5, S355J2+C. The tool (circular saw) was measured before and after machining of steel.
PL
Pomimo powszechnego dążenia do produkowania coraz lżejszych, tańszych i wytrzymalszych komponentów ze stopów metali lekkich oraz tytanu, to żeliwo jest nadal materiałem dość powszechnie wykorzystywanym w branży mechanicznej, jak również w przemyśle motoryzacyjnym. Produkowane z niego są głownie korpusy elementów układu przeniesienia napędu jak również części wykorzystywane w oprzyrządowaniu silnika. Masowy charakter produkcji w branży motoryzacyjnej wpływa natomiast na konieczność zapewnienia dużej wydajności objętościowej procesu skrawania. W literaturze światowej jest wiele pozycji dotyczących doboru technologicznych para-metrów obróbki przy wysokowydajnym skrawaniu, stali, stopów metali lekkich oraz tytanu. Natomiast w przypadku żeliw takie prace stanowią ułamek procenta publikowanych obecnie prac. Stąd w oparciu o zapotrzebowanie zaspokojenia potrzeb przemysłu oraz chęci poznawczych zespołu badawczego, podjęto się tematyki badań doświadczalnych, których wyniki zostały opisane w poniższym artykule. Celem realizowanych badań było określenie możliwości wykorzystania jednego narzędzia do obróbki zgrubnej i wykończeniowej uwzględniając jedynie możliwości zmiany technologicznych parametrów obróbki dwóch zabiegów zintegrowanych w jednej operacji.
EN
Despite the widespread desire to produce lighter, cheaper and more durable components from light metal alloys and titanium, cast iron is still a material widely used in the mechanical industry as well as in the automotive industry. The parts used in the engine's instrumentation are mainly produced from it. However, the mass nature of production in the automotive industry affects the need to ensure high volume efficiency of the cutting process. In the world science literature there are many items regarding the selection of technological machining parameters for high-performance machining, steel, light metal alloys and titanium. In the case of cast irons, such works constitute a fraction of a percentage of the currently published works. Therefore, on the basis of the demand to meet the industry's needs and the cognitive intentions of the research team, the subject of experimental research was carried out and the results of which were described in the following article. The aim of the research was to determine the possibility of using one tool for roughing and finishing machining, taking into account only the possibility of changing the technological parameters of processing two treatments integrated in one operation.
EN
The study presents a durability analysis of dies used in the first operation of producing a valve-type forging from high nickel steel assigned to be applied in motor truck engines. The analyzed process of producing exhaust valves is realized in the forward extrusion technology and next through forging in closed dies. It is difficult to master, mainly due to the increased adhesion of the charge material (high nickel steel) to the tool’s substrate. The mean durability of tools made of tool steel W360, subjected to thermal treatment and nitriding, equals about 1000 forgings. In order to perform a thorough analysis, complex investigations were carried out, which included: a macroscopic analysis combined with laser scanning, numerical modelling by FEM, microstructural tests on a scanning electron microscopy and light microscopy (metallographic), as well as hardness tests. The preliminary results showed the presence of traces of abrasive wear, fatigue cracks as well as traces of adhesive wear and plastic deformation on the surface of the dies. Also, the effect of the forging material being stuck to the tool surface was observed, caused by the excessive friction in the forging’s contact with the tool and the presence of intermetallic phases in the nickel-chromium steel. The obtained results demonstrated numerous tool cracks, excessive friction, especially in the area of sectional reduction, as well as sticking of the forging material, which, with insufficient control of the tribological conditions, may be the cause of premature wear of the dies.
EN
In the present work, the performance of multilayer coated carbide tool was investigated considering the effect of cutting parameters during turning of 34CrMo4 Low alloy steel. It has high strength and creep strength, and good impact tenacity at low temperature. It can work at –110°C to 500°C. And EN 10083-1 34CrMo4 owns high static strength, impact tenacity, fatigue resistance, and hardenability; without overheating tendencies. The objective functions were selected in relation to the parameters of the cutting process: surface roughness criteria. The correlations between the cutting parameters and performance measures, like surface roughness, were established by multiple linear regression models. Highly significant parameters were determined by performing an Analysis of variance (ANOVA). During the experiments flank wear, cutting force and surface roughness value were measured throughout the tool life. The results have been compared with dry and wet-cooled turning. Analysis of variance factors of design and their interactions were studied for their significance. Finally, a model using multiple regression analysis between cutting speed, fee rate and depth of cut with the tool life was established.
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