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EN
This paper presents the results of experimental study of the AZ31 magnesium alloy milling process. Dry milling was carried out under high-speed machining conditions. First, a stability lobe diagram was determined using CutPro software. Next, experimental studies were carried out to verify the stability lobe diagram. The tests were carried out for different feed per tooth and cutting speed values using two types of tools. During the experimental investigations, cutting forces in three directions were recorded. The obtained time series were subjected to general analysis and analysis using composite multiscale entropy. Modelling and prediction were performed using Statistica Neural Network software, in which two types of neural networks were applied: multi-layered perceptron and radial basis function. It was observed that milling with high cutting speed values allows for component values of cutting force to be lowered as a result of the transition into the high-speed machining conditions range. In most cases, the highest values for the analysed parameters were recorded for the component Fx, whereas the lowest were recorded for Fy. Additionally, the paper shows that a prediction (with the use of artificial neural networks) of the components of cutting force can be made, both for the amplitudes of components of cutting force Famp and for root mean square Frms.
PL
Analizowano wpływ zmiany parametrów technologicznych – posuwu oraz prędkości skrawania – na wybrane parametry chropowatości 2D po toczeniu. Wykorzystano stop aluminium EN-AW 7075 (AlZn5.5MgCu). Wykazano istotny wpływ posuwu oraz brak wpływu prędkości skrawania na parametry chropowatości powierzchni. W celu przedstawienia możliwości predykcji parametrów chropowatości tego procesu wykonano symulację jednego z nich (Rz) z wykorzystaniem sztucznych sieci neuronowych.
EN
The purpose of this investigation was to determine whether and to what extent the technological parameters of turning (feed, cutting speed) affect selected surface roughness parameters of aluminum alloy EN-AW 7075 (AlZn5.5MgCu). The principal findings indicate a significant impact of feed and show on the surface roughness and simultaneously show that cutting speed has no effect on the value of surface roughness parameters under investigation. An artificial neural network was employed to evaluate the prediction of surface roughness parameter Rz in turning.
EN
The paper reports the results of artificial neural network modelling of vibration in a milling process of magnesium alloy AZ91D by a TiAlN-coated carbide tool. Vibrations in machining processes are regarded as an additional, absolute machinability index. The modelling was performed using the so-called “black box” model. The best fit was determined for the input and output data obtained from the machining process. The simulations were performed by the Statistica software using two types of neural networks: RBF (Radial Basis Function) and MLP (Multi-Layered Perceptron).
PL
Analizowano wpływ zmiany parametrów technologicznych (vc, f) na wybrane parametry stanu warstwy wierzchniej po toczeniu. Zaprezentowano parametry chropowatości 2D. W badaniach wykorzystano stop aluminium 7075.
EN
The study is an analysis of the effect of technological parameters of turning (vc, f) on the subsurface layer of 7075 aluminum alloy. The study included 2D surface roughness parameters. In this study was used 7075 aluminum alloy.
5
Content available remote Fragmentowanie oraz frakcje wiórów podczas frezowania stopów magnezu
PL
Analizowano wpływ parametrów technologicznych (vc, fz, ap) oraz geometrii ostrza narzędzia (γ) na powstawanie frakcji wiórów. Przedstawiono wyniki badań masy dla frakcji wiodącej wiórów ze stopu magnezu AZ91HP. Stwierdzono istotny wpływ parametrów technologicznych na jednostkową masę frakcji wiodącej wiórów.
EN
The study investigated the impact of technological parameters (vc, fz, ap) and the end-mill geometry on the formation of chip fractions. The paper reports the results of the mass of a leading chip fraction made of AZ91HP alloy. The results show a significant influence of the technological parameters on the unit mass of the leading chip fraction.
EN
This paper presents an overview of the state of knowledge on temperature measurement in the cutting area during magnesium alloy milling. Additionally, results of own research on chip temperature measurement during dry milling of magnesium alloys are included. Tested magnesium alloys are frequently used for manufacturing elements applied in the aerospace industry. The impact of technological parameters on the maximum chip temperature during milling is also analysed. This study is relevant due to the risk of chip ignition during the machining process.
EN
Magnesium alloys are used as advanced structural materials for producing machine components for the aircraft or automotive industry. The machining of these components involves the risk of uncontrolled ignition during machining operations and production of fine-grained chip fractions causing the wear of kinematic pairs in technological machines. Given the operation of machine tools, the determination of a method for assessing risk based on determining a safe milling range and suitable operational parameters seems justified. The paper presents the results of investigations on chip fragmentation, chip mass and dimensions. Based on these parameters, we determine effective and safe regions with respect to operation of machine tools. The experiments are performed on magnesium alloy AZ91HP, one of the most widely used casting alloys.
PL
Stopy magnezu są wykorzystywane jako nowoczesne materiały konstrukcyjne na elementy maszyn wytwarzane m.in. na potrzeby przemysłu lotniczego czy motoryzacyjnego. Obróbka skrawaniem tych elementów wiąże się z ryzykiem niekontrolowanego zapłonu podczas wykonywania operacji obróbkowych oraz powstawaniem drobnoziarnistych frakcji wiórów powodujących przyspieszone zużycie węzłów kinematycznych maszyn technologicznych. Zaproponowanie oceny ryzyka związanego z wyborem zakresu, uznawanego za bezpieczny, parametrów technologicznych frezowania, wydaje się celowe ze względów eksploatacyjnych maszyn obróbkowych. W artykule przedstawiono wyniki badań fragmentacji wiórów, ich masy oraz wymiarów charakterystycznych wiórów. Istotnym wydaje się określenie (na podstawie wymienionych wskaźników) obszarów uznawanych ze efektywne a zarazem bezpieczne z punktu widzenia eksploatacji maszyn obróbkowych. Do badań wytypowano często stosowany stop magnezu, z grupy odlewniczych, AZ91HP.
EN
The paper presents simulation of the cutting force components for ma-chining of magnesium alloy AZ91HP. The simulation employs the Black Box model. The closest match to (input and output) data obtained from the machining process was determined. The simulation was performed with the use of the Statistica programme with the application of neural networks: RBF (Radial Basis Function) and MLP (Multi-Layered Perceptron).
EN
The paper analyses the impact of specified technological parameters of milling (vc , fz, ap ) on time to ignition. Stages leading to chip ignition were analysed. Metallographic images of magnesium chip were presented. No significant difference was observed in time to ignition in different chip fractions. Moreover, the surface of chips was free of products of ignition and signs of strong oxidation.
10
Content available remote Klejenie w technologii szybkiego prototypowania
PL
Klejenie może być interesującym uzupełnieniem dla technologii przyrostowych w wytwarzaniu prototypów. W pracy przedstawiono przykłady możliwości wykorzystania klejenia w technologii prototypów, niektóre charakterystyki klejów określone w badaniach oraz wskazano na zalety i ograniczenia w stosowaniu tej technologii.
EN
Gluing can be an interesting supplement for of incremental technology in the manufacture of prototypes. The paper presents examples of the possibilities of using gluing in prototypes technology, some of the characteristics of the glues specified in the research and pointed out the advantages and limitations in the application of this technology.
EN
The article presents test results of surface roughness after AZ91HP magnesium alloy machining with variable technological parameters (vc, fz, ap) as well as tool geometry (γ= 5◦ and γ = 30◦). Two carbide end mills were applied during the tests. Roughness analysis was conveyed at the end face (Ra, Rq, RzDIN, Rt, Ry, RSm) and lateral face (Ra, Rz, RSm) of the tested sample. A decrease of roughness parameters (for increasing vc) as well as an increase (with growing fz) was observed in the lateral face tests. Similar interrelations were noticed for end face of the sample. Lower roughness parameters values were recorded for tool rake angle equal to γ = 5◦.
EN
Safety of Mg milling processes can be expressed by means of the form and the number of fractions of chips formed during milling. This paper presents the state of the art of magnesium alloys milling technology in the aspect of chip fragmentation. Further-more, the impact of the depth of cut ap and the rake angle γ on the number of chip fractions was analysed in the study. These were conducted on AZ91HP magnesium cast alloy and milling was performed with carbide tools of varying rake angle values (γ = 5º and γ = 30º). It was observed that less intense chip fragmentation occurs with decreasing depth of cut ap. The number of chip fractions was lower at the tool rake angle of γ = 30º. The test results were formulated as technological recommendations according to the number of generated chip fractions.
EN
Machining process nowadays could not be conducted without its inseparable element: cutting edge and frequently numerically controlled milling machines. Milling and lathe machining centres comprise standard equipment in many companies of the machinery industry, e.g. automotive or aircraft. It is for that reason that tertiary education should account for this rising demand. This entails the introduction into the curricula the forms which enable visualisation of machining, milling process and virtual production as well as virtual machining centres simulation. Siemens Virtual Machine (Virtual Workshop) sets an example of such software, whose high functionality offers a range of learning experience, such as: learning the design of machine tools, their configuration, basic operation functions as well as basics of CNC.
EN
This work discusses computational capabilities of the programs belonging to the CAS (Computer Algebra Systems). A review of commercial and non-commercial software has been done here as well. In addition, there has been one of the programs belonging to the this group (program Mathcad) selected and its application to the chosen example has been presented. Computational capabilities and ease of handling were decisive factors for the selection.
EN
This article presents the state of knowledge on cutting forces during the milling of light alloys. Research results presented in the paper concern cutting forces and their amplitudes depending on the technological parameters (vc, fz, ap) with the use of two carbide milling cutters having a different cutting edge geometry (γ=5º and γ=30º). Research and analysis of cutting forces appear to be a significant factor determining chip deformation, temperature and cutting area strain, among others. Lower values of cutting force components are observed in the case of γ=30º tool processing. For the purpose of this research casting magnesium alloy AZ91HP was selected.
PL
W pracy wykonano analizę ogólnego stanu wiedzy dotyczącą sił skrawania podczas frezowania stopów lekkich. Przedstawiono wyniki pomiarów sił skrawania w zależności od zmiany określonych parametrów technologicznych (vc, fz, ap) przy zastosowaniu dwóch frezów węglikowych o zmiennej geometrii ostrza (γ=5º i γ=30º). Ustalono, że wartości sił skrawania są czynnikiem determinującym m.in. odkształcanie się wióra, temperaturę oraz odkształcenia materiału warstwy wierzchniej w strefie skrawania. Mniejsze wartości składowych sił skrawania stwierdzono dla obróbki narzędziem o kącie γ=30º. Proces obróbki prowadzono dla stopu magnezu AZ91HP.
17
Content available remote Badania mikrotwardości stopów magnezu po szybkościowym frezowaniu na sucho
PL
Stopy magnezu są często wykorzystywane na elementy maszyn, zwłaszcza przez przedsiębiorstwa branży lotniczej. Produkcja nowoczesnych elementów lotniczych związana jest z efektywną obróbką szybkościową. Wydajne frezowanie może prowadzić do zmian właściwości fizycznych warstwy wierzchniej. Głównym celem badań była analiza wpływu parametrów technologicznych frezowania na mikrotwardość.
EN
Magnesium alloys are commonly used for manufacturing various components, in particular by companies in the aerospace industry. Modern aerospace components production is largely related to efficient high-speed machining. Efficient milling can result in changing physical properties of the surface layer. The aim of the study was to analyse the correlation between technological parameters of milling operations and the surface layer microhardness.
EN
This paper presents a literature review on temperature measurement during milling of magnesium alloys as well as other structural materials. Methodology and temperature measurement methods used in own tests are discussed in this paper. Selected test results for each method of temperature measurement in the cutting area are demonstrated.
EN
This paper presents the state of knowledge on cutting forces values during milling of different magnesium alloy types. Additionally, the results of own research on cutting forces and their amplitudes after milling magnesium alloys used for manufacturing elements applied in the aerospace industry are included. The subject of the analysis was the influence of technological parameters and the tool type on cutting forces and their amplitudes. The analysis is important due to the correlation between cutting forces and temperature in the cutting area, and, consequently, the safety of machining and strain of the workpiece.
PL
Jednym w ważniejszych celów przedsiębiorstw branży lotniczej jest produkcja coraz lżejszych samolotów/śmigłowców oraz zmniejszenie zużycia paliwa. Jest to możliwe dzięki zastosowaniu elementów wykonywanych ze stopów magnezu. W prezentowanym artykule przedstawiono wyniki badań sił skrawania i ich amplitud po frezowaniu dwóch stopów magnezu AZ31 oraz AZ91HP. Obserwowano wpływ parametrów technologicznych oraz rodzaju narzędzia na wartość sił skrawania oraz ich amplitud. Analiza sił jest ważnym zagadnieniem ze względu na deformację wióra, a co za tym idzie również ze względu na odkształcenia oraz temperaturę w strefie skrawania.
EN
One of the most important company objectives for aerospace industry are the production of lighter airplanes/helicopters and reduced fuel consumption. In order to this components made of magnesium alloys should be used. The results of investigation of cutting forces and their amplitudes after milling two magnesium alloys AZ31 and AZ91HP were presented in this article. Influence of technological parameters and the type of used tools on the value of cutting forces was observed. The forces analysis is an important problem due to the deformation of the chip, and therefore also due to the strain and temperature in the cutting area.
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