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Search results for: milling
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Adjusting the Stiffness of Supports during Milling of a Large-Size Workpiece Using the Salp Swarm Algorithm
PublicationThis paper concerns the problem of vibration reduction during milling. For this purpose, it is proposed that the standard supports of the workpiece be replaced with adjustable stiffness supports. This affects the modal parameters of the whole system, i.e., object and its supports, which is essential from the point of view of the relative tool–workpiece vibrations. To reduce the vibration level during milling, it is necessary to...
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The clamping selection method to reduce the vibration of large-size workpieces during the face milling process
PublicationThe article introduces a method for selecting the best clamping conditions to obtain vibration reduction during milling of large-size workpiece. It is based on experimental modal analysis performed for a set of assumed, fixing conditions of a considered workpiece to identify Frequency Response Functions (FRFs) for each tightening torque of the mounting screws. Simulated plots of periodically changing nominal cutting forces are...
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Optimal spindle speed determination for vibration reduction during ball-end milling of flexible details
PublicationIn the paper a method of optimal spindle speed determination for vibration reduction during ball-end milling of flexible details is proposed. In order to reduce vibration level, an original procedure of the spindle speed optimisation, based on the Liao–Young criterion, is suggested. As the result, an optimal, constant spindle speed value is determined. For this purpose, on-stationary computational model of machining process is...
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High Speed Milling vibration surveillance with optimal spindle speed based on optimal speeds map
PublicationThe paper presents the method of the surveillance of the self-excited chatter vibration. At first, the workpiece modal parameters are estimated based on experimental data which leads to verification of computational model. Then, for selected surface points optimal spindle speeds are calculated. By considering sufficient amount of points it is possible to build a map of optimal spindle speeds. Experimental results show that this...
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Convenient and efficient N-methylation of secondary amines under solvent-free ball milling conditions
PublicationIn the present work, we report the development of a rapid, efcient, and solvent-free procedure for the N-methylation of secondary amines under mechanochemical conditions. After optimization of the milling parameters, a vibrational ball mill was used to synthesize 26 tertiary N-methylated amine derivatives in a short time of 20 min (30 Hz frequency) and high yields ranging from 78 to 95%. An exception was compounds having a hydroxyl...
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A novel method for vibration surveillance during high speed ball end milling of flexible details
PublicationPraca dotyczy nadzorowania drgań podczas obróbki zakrzywionych przedmiotów podatnych frezem kulistym, z uwzględnieniem zgodności parametrów modelu modalnego. Przedstawiono analizę dynamiki niestacjonarnego okładu drgającego, z którego wydzielono podukład modalny, strukturalny i łączący. Zastosowano minimalizację poziomu drgań z dopasowaniem prędkości obrotowej wrzeciona do optymalnego kąta przesunięcia fazowego. Eksperymenty doświadczalne...
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A novel method for vibration surveillance during high speed ball end milling of flexible details
PublicationPraca dotyczy nadzorowania drgań układów niestacjonarnych modelowanych metodą elementów skończonych. Obróbka frezem kulistym przedmiotów podatnych jest często stosowana w przypadku nowoczesnych centrów obróbkowych. Drgania względne narzędzie-przedmiot obrabiany mogą doprowadzić do utraty stabilności i powstania drgań samowzbudnych typu chatter. W pracy proponuje się metodę minimalizacji poziomu drgań poprzez dopasowanie prędkości...
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SURFACE TEXTURE ANALYSIS AFTER BALL END MILLING WITH VARIOUS SURFACE INCLINATION OF HARDENED STEEL
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Optimisation of machining parameters during ball end milling of hardened steel with various surface inclinations
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Creation of a map of optimal spindle speeds for a purpose of surveillance of high speed milling of flexible details
PublicationDrgania samowzbudne typu chatter często towarzyszą procesom frezowania szybkościowego. Ich skutkiem są nieodwracalne uszkodzenia powierzchni obrabianej. Mogą one również doprowadzić do intensywnego zużycia narzędzi skrawających, a nawet samej obrabiarki. W pracy przedstawiono metodę umożliwiającą tworzenie mapy optymalnych prędkości obrotowych wrzeciona. Stosowanie podczas procesu frezowania optymalnej prędkości obrotowej wrzeciona...
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The Optimal Spindle Speed Map for Reduction of Chatter Vibration During Milling of Bow Thruster Blade
PublicationW artykule przedstwiono przykład wykorzystania procedury tworzenia mapy optymalnych prędkosci obrotowych w celu ograniczenia drgań samowzbudnych podczas frezowania płata śruby okrętowego steru strumieniowego.
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Vibration surveillance in the hybrid system on example of milling flexible details and considering assurance of modal subsystem.
PublicationPraca dotyczy nadzorowania drgań dużych mechanicznych układów niestacjonarnych modelowanych dyskretnie, za pomocą sterowania optymalnego przy energetycznym wskaźniku jakości. W układzie drgającym wyodrębniono podukład modalny, podukład strukturalny oraz podukład łączący. Dynamikę układu sterowanego opisano we współrzędnych hybrydowych, przez co uzyskano znacznie mniejszy rząd niż w przypadku modelu strukturalnego. Zdefiniowano...
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Reduction of vibration level by the spindle speed optimisation during ball end milling of flexible details
PublicationPraca dotyczy nadzorowania drgań podczas skrawania przedmiotów podatnych frezem kulistym. Przedsatwiono wspomaganą komputerowo procedurę nadzorowania z optymalizacją prędkości obrotowej narzędzia. Przy modelowaniu wykorzystano niestacjonarny model obliczeniowy. Rezultatem modelowania jest układ hybrydowy, w którym oddzielono podukłady: modalny, łączący i strukturalny. Metoda wymaga identyfikacji częstości własnych co może być wykonane...
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A method of predicting the best conditions for large-size workpiece clamping to reduce vibration in the face milling process
PublicationThe paper presents an innovative method of solving the problem of vibration suppression during milling of large-size details. It consists in searching for the best conditions for clamping the workpiece based on a rapid modal identification of the dominant natural frequencies only and requires repetitive changes in the tightening torque of the clamping screws. Then, by estimating the minimum work of the cutting forces acting in...
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The estimation of cutting forces and specific force coefficients during finishing ball end milling of inclined surfaces
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A Mechatronic System for Building the Map of Optimal Spindle Speeds During High Speed Milling of Flexible Details
PublicationW pracy przedstawiono mechatroniczny system tworzenia mapy optymalnych prędkości obrotowych wrzeciona w celu nadzorowania drgań typu chatter podczas frezowania szybkościowego przedmiotów podatnych. System ten składa się z części pomiarowej oraz części obliczeniowej, w której wykorzystuje się oprogramowanie autorskie i komercyjne. Na bazie uogólnionego warunku Liao-Younga utworzono mapy optymalnych prędkości obrotowych wrzeciona,...
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ALTERNATIVE, DIRECT SYNTHESIS METHOD OF THE CERAMIC SOLID SOLUTIONS BASED ON BaTiO3 THROUGH A HIGH ENERGY BALL MILLING
PublicationPolycrystalline samples BaTiO3 and the solid solutions Ba0.9Sr0.1TiO3, Ba0.9Sr0.1Ti0.9Sn0.1O3, Ba0.9Sr0.1Ti0.8Sn0.2O3 were obtained by means of a mechanochemical treatment based on the high-energy ball milling technique and next a high temperature solid state reaction method. The influence of synthesis condition on microstructural, dielectric and ferroelectric properties of obtained solid solutions were investigated. The structure...
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Optimization of the spindle speed during milling of large-sized structures with the use of technique of Experiment-Aided Virtual Prototyping
PublicationIn the paper are presented considerations concerning vibration suppression problems during milling of large-sized workpieces with the use of innovative method of matching the spindle speed of cutting tool. It depends on repeatable change of the spindle speed value as soon as the optimal vibration state of the workpiece approaches. The values of dominant “peaks” in the frequency spectra and the Root Mean Square (RMS) values of time...
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Study of the influence of high-energy milling time on the Cu–13Al–4Ni alloy manufactured by powder metallurgy process
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Study on metrological relations between instant tool displacements and surface roughness during precise ball end milling
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The optimal control at energy performance index as a rule for vibration surveillance in the hybrid system by on example of milling flexible details
PublicationPraca dotyczy nadzorowania drgań w niestacjonarnych układach mechanicznych za pomocą sterowania optymalnego pry energetycznym wskaźniku jakości. W układzie drgającym wyodrębniono podukłady: modalny, strukturalny oraz łączący. Dynamikę układu sterowanego opisano we współrzędnych hybrydowych. Przedstawiono przykład nadzorowania drgań podczas obróbki przedmiotów podatnych smukłym frezem kulistym. Paramatry obliczeniowego modelu modalnego...
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Optimization of clamping stiffness during milling of high-dimensional structures with the use of techniques of experiment – aided virtual prototyping
PublicationThe subject of this paper is a method of searching for conditions of minimizing the vibration level of a tool-high dimensional flexible workpiece, at unchangeable technological parameters of the machining process. It depends on repeatable change of the values of the stiffness coefficients as soon as an optimal vibration state of the workpiece approaches. There are assessed the values of dominant ”peaks” in the frequency spectra...
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An Experimentally Aided Operational Virtual Prototyping to Obtain the Best Spindle Speed during Face Milling of Large-Size Structures
PublicationAbstract: The paper presents an original method concerning the problem of vibration reduction in the general case while milling large-size and geometrically complex details with the use of an innovative approach to the selection of spindle speed. A computational model is obtained by applying the so-called operational approach to identify the parameters of the workpiece modal model. Thanks to the experimental modal analysis results,...
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A technique of experiment aided virtual prototyping to obtain the best spindle speed during face milling of large-size structures
PublicationThe paper presents an original method concerning vibration suppression problem during milling of large-size and geometrically complicated workpieces with the use of novel way of selecting the spindle speed. This consists in repetitive simulations of the cutting process for subsequent values of the spindle speed, until the best vibration state of the workpiece is reached. An appropriate method of obtaining a computational model,...
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Vibration surveillance during ball end milling of curved flexible details on a basis of assessment of assurance of the model of real object
PublicationW pracy przedstawiono nową metodę nadzorowania drgań podczas frezowania zakrzywionych przedmiotów podatnych. Wykorzystano model modalny przedmiotu obrabianego, którego parametry zidentyfikowano na bazie badań doświadczalnych oraz analizy komputerowej. Zastosowanie modelu metody elementów skończonych, którego zachowanie jest zgodne z przedmiotem uformowanym w postaci cienkościennej powierzchni półwalcowej, a następnie - utworzenie...
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Modeling flatness deviation in face milling considering angular movement of the machine tool system components and tool flank wear
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Application of signal to noise ratio and grey relational analysis to minimize forces and vibrations during precise ball end milling
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Effect of ball-milling process parameters on mechanical properties of Al/Al2O3/collagen powder composite using statistical approach
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Surface Roughness Evaluation in Thin EN AW-6086-T6 Alloy Plates after Face Milling Process with Different Strategies
PublicationLightweight alloys made from aluminium are used to manufacture cars, trains and planes. The main parts most often manufactured from thin sheets requiring the use of milling in the manufacturing process are front panels for control systems, housing parts for electrical and electronic components. As a result of the final phase of the manufacturing process, cold rolling, residual stresses remain in the surface layers, which can influence...
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Vibration surveillance during ball end milling of curved flexible details, considering an assessment of assurance between analysis and test model
PublicationPraca dotyczy nadzorowania drgań podczas obróbki smukłym frezem kulistym przedmiotów podatnych o powierzchniach zakrzywionych. Przedstawiono analizę dynamiczną niestacjonarnego układu drgającego, w którym wyodrębniono podukłady: modalny, strukturalny i łączący. Dokonano oceny zgodności wyników obliczeń numerycznych z wynikami pomiarów na frezarce Mikron VCP 600.
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High-Performance Face Milling of 42CrMo4 Steel: Influence of Entering Angle on the Measured Surface Roughness, Cutting Force and Vibration Amplitude
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Effect of Thermal Treatment of Birch Wood by Saturated Water Vapor on Granulometric Composition of Chips from Sawing and Milling Processes from the Point of View of Its Processing to Composites
PublicationThe goal of this work is to investigate the impact of thermal modification of birch wood with saturated steam on the particle size distribution of the sawing and milling process. Birch wood (Betula pendula Roth) is an excellent source to produce plywood boards. Wastes from mechanical processing of birch wood are suitable to produce composite materials. Granulometric analyses of chips from sawing processes on the PRW 15M frame saw,...
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Tool wear, surface roughness, cutting temperature and chips morphology evaluation of Al/TiN coated carbide cutting tools in milling of Cu–B–CrC based ceramic matrix composites
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Tailoring a low-energy ball milled MnCo2O4 spinel catalyst to boost oxygen evolution reaction performance
PublicationThe development of cost-efficient oxygen evolution reaction (OER) catalysts is one of the most important tasks facing modern techniques for hydrogen production. In this work, for the first time, a low-energy ball milling process of MnCo2O4 (MCO) spinel powders, with a mechanical modification time exceeding 1 day was used. After 6 days of ball-milling, the obtained overpotential of the electrocatalyst reached the value of 375 mV...
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Microstructural Design of Ba0.5La0.5Co0.5Fe0.5O3 Perovskite Ceramics
PublicationBa0.5La0.5Co0.5Fe0.5O3 was synthesized in the solid-state reaction route. The influence of ball milling parameters (such as milling media size, angular velocity, and time), pelletizing pressure, and annealing parameters on the microstructure was studied. The grain size distribution and density or specific surface area changes were investigated in each approach while the individual parameters were changed. The evaluation of BLCF...
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An investigation of microstructural basis for corrosion behavior of Al-CNT composites fabricated by SPS
PublicationIn this research effect of the addition of multi-wall carbon nanotubes (MWCNTs) as additive powder on microstructure and corrosion behavior of fabricated Al-CNT composites was studied. The aluminum powder and CNTs were mixed with high energy planetary ball-mill. It is observed that by increasing milling time, the uniformity of CNTs on aluminum matrix and consequently corrosion resistance of Al-CNT composite is increased. On the...
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STRUCTURE AND MAGNETIC PROPERTIES OF Bi5Ti3FeO15 CERAMICS PREPARED BY SINTERING, MECHANICAL ACTIVATION AND EDAMM PROCESS. A COMPARATIVE STUDY
PublicationThree different methods were used to obtain Bi5Ti3FeO15 ceramics, i.e. solid-state sintering, mechanical activation (MA) with subsequent thermal treatment, and electrical discharge assisted mechanical milling (EDAMM). The structure and magnetic properties of produced Bi5Ti3FeO15 samples were characterized using X-ray diffraction and Mössbauer spectroscopy. The purest Bi5Ti3FeO15 ceramics was obtained by standard solid-state sintering...
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Comparative X-ray diffraction and Mössbauer spectroscopy studies of BiFeO3 ceramics prepared by conventional solid-state reaction and mechanical activation
PublicationThe aim of this work was to prepare BiFeO3 by modified solid-state sintering and mechanical activation processes and to investigate the structure and hyperfine interactions of the material. X-ray diffraction and Mössbauer spectroscopy were applied as complementary methods. In the case of sintering, BiFeO3 phase was obtained from the mixture of precursors with 3 and 5 % excess of Bi2O3 during heating at 1023 K. Small amounts of...
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ESTYMACJA WSPÓŁCZYNNIKÓW SZTYWNOŚCI ZAMOCOWANIA PODATNEGO PRZEDMIOTU OBRABIANEGO NA STOLE FREZARKI
PublicationW pracy przedstawiono metodę estymacji współczynników sztywności Elementów Sprężystych (ES) modelujących zamocowanie podatnego wielkogabarytowego przedmiotu obrabianego na stole frezarki. Proponowana metoda bazuje na algorytmie optymizacji za pomocą roju cząstek (ang. Particle Swarm Optimization), który pozwala na uzyskanie dobrej zgodności (aktualizacji) modelu Metody Elementów Skończonych (MES) z modelem pochodzącym z identyfikacji...
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Mg2+ Doping Effects on the Structural and Dielectric Properties of CaCu3Ti4O12 Ceramics Obtained by Mechanochemical Synthesis
PublicationIn this study, ceramic CaCu3Ti4O12 (CCTO) and CaCu3−xMgxTi4O12 solid solutions in which 0.1 ≤ x ≤ 0.5 were prepared by the mechanochemical method, realized by a high‐energy ball milling technique. The effects of the Mg2+ ion concentration and sintering time on the dielectric response in the prepared ceramics were investigated and discussed. It was demonstrated that, by the use of a sufficiently high energy of mechanochemical treatment,...
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A Surveillance Of Dynamic Processes in Selected Mechatronic Systems
PublicationThe paper concerns development of original method of optimal control at energy performance index and its application to dynamic processes surveillance of some mechatronic systems. The latter concerns chatter vibration surveillance during highspeed slender milling of rigid details, as well as motion control of two-wheeled mobile platform. Results of on-line computer simulations and real performance on the target objects reflect...
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Nanotechnologies in Development of Structural Materials and Biomaterials
PublicationThe nanometric materials and technologies resulted in nanostructures are reviewed. The examples of nanomaterials are shown. The typical nanotechnologies, including plastic deformation, mechanical attrition, controlled detonation, hot plasma jet synthesis, laser vaporisation, CVD and PVD, mechanical milling, annealing, ultrasonic irradiation, nanolithography, electrocrystallisation, electrospinning, sol-gel method, cryogenic laser-enhanced...
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A modified method of vibration surveillance by using the optimal control at energy performance index
PublicationA method of vibration surveillance by using the optimal control at energy performance index has been creatively modified. The suggested original modification depends on consideration of direct relationship between the measured acceleration signal and the optimal control command. The paper presents the results of experiments and Hardware- in-the-loop simulations of a new active vibration reduction algorithm based on the energy...
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Structure and thermoelectric properties of Cs-Bi-Te alloys fabricated by different routes of reduction of oxide reagents
PublicationCesium-bismuth-telluride polycrystalline materials were fabricated using a cost-effective method based on a reduction of oxide reagents, leading to a production of a material with good thermoelectric properties. Several samples with various initial stoichiometry were prepared by melting of oxide powders at 1050 °C, quenching, milling to powders and then reducing in pure hydrogen at 400 °C. Another concept was to obtain the CsBi4Te6...
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The effect of thermal modification on the quality of the milled surface of beech and pine wood
PublicationThe article deals with the effect of thermal modification on the quality of the created surface during milling on CNC milling cutters. The quality of the created surface is evaluated based on surface roughness, specifically its roughness parameter Ra. The observed surface is created by a shank cutter with a diameter of 20 mm and three cutting edges in a spiral at a standard speed of 18,000. min-1. The article compares thermally...
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Structure and thermoelectric properties of bismuth telluride—Carbon composites
PublicationCarbon nanotubes and amorphous carbon have been introduced into a bismuth telluride matrix (0.15 and 0.30 wt.% ratio) to investigate the influence of the carbon on the composite’s thermoelectric properties. Composites with well-dispersed additives have been obtained by sonication and ball-milling methodology. Carbon nanotubes and an amorphous carbon addition led to a decrease in electric conductivity from 1120 S/cm to 77 S/cm....
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Tetrahedrally modified MnMe0.1Co1.9O4 (Me = Zn, Mg, Li) spinels for non-enzymatic glucose sensing
PublicationIn this work, tetrahedrally modified MnMe0.1Co1.9O4 (Me = Zn, Mg, Li) spinels were prepared via the sol–gel synthesis method with subsequent ball-milling fragmentation. The prepared samples were evaluated as glucose–sensing catalyst. The reference MnCo2O4 spinel exhibited a sensitivity of 49 µA mM−1 cm−2 and a nonlinearity error of 5.2% in the response range from 0.02 to 1 mM. The partial substitution of cobalt in the reference...
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VARIABLE KINEMATICS OF HONING PROCESS – INFLUENCE ON MACHINED WORKPIECE
PublicationSurface quality of holes plays an important role in machine manufacturing industry especially in the production of car engines and hydraulic cylinders. Investigations of honing process were carried out by 6 years on horizontal CNC Sunnen’s honing machine HTH 4000S, on vertical conventional honing machine WMW’s SZS 200 and on CNC milling machine of Haas VF 3SS with equipment of Honingtec for honing. Measurements of cylindricity...
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Solvent-Free Synthesis of Phosphonic Graphene Derivative and Its Application in Mercury Ions Adsorption
PublicationFunctionalized graphene was efficiently prepared through ball-milling of graphite in the presence of dry ice. In this way, oxygen functional groups were introduced into material. The material was further chemically functionalized to produce graphene derivative with phosphonic groups. The obtained materials were characterized by spectroscopic and microscopic methods, along with thermogravimetric analysis. The newly developed material...
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MULTI-CRITERIA COMPARATIVE ANALYSIS OF THE USE OF SUBTRACTIVE AND ADDITIVE TECHNOLOGIES IN THE MANUFACTURING OF OFFSHORE MACHINERY COMPONENTS
PublicationThe dynamic development of additive manufacturing technologies, especially over the last few years, has increased the range of possible industrial applications of 3D printed elements. This is a consequence of the distinct advantages of additive techniques, which include the possibility of improving the mechanical strength of products and shortening lead times. Offshore industry is one of these promising areas for the application...