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Obróbka elektroerozyjna z płatkami grafenowymi w dielektryku

Świercz R.

Mechanik

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2017

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R. 90, nr 3

186--187

PL

Przedstawiono analizę statystyczną wyników badań doświadczalnych obróbki EDM stali w roztworze nafty z płatkami grafenowymi oraz w dielektryku na bazie nafty. Wyznaczono równania regresji opisujące wpływ parametrów i warunków obróbki na wybrane parametry chropowatości powierzchni.

EN

The article presents statistical analysis of results experimental investigation of EDM process with graphene flakes in dielectric. The relations between surface roughness and process parameters have been determined.

2

Obróbka elektroerozyjna – badanie impulsów elektrycznych napięcia i natężenia prądu

Oniszczuk-Świercz D., Świercz R.

Mechanik

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2017

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R. 90, nr 2

112--113

PL

W artykule przedstawiono wyniki badań doświadczalnych monitorowania przebiegów napięciowo-prądowych w warunkach obróbki elektroerozyjnej. Określono wpływ parametrów procesu erozji na stabilność obróbki.

EN

The article presents results of monitoring current and voltage waveforms in EDM process. The relations between process parameters and stability of electrical erosion have been determined.

3

Wpływ właściwości dielektryka na chropowatość powierzchni po obróbce elektroerozyjnej

Oniszczuk-Świercz D., Świercz R.

Mechanik

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2016

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R. 89, nr 12

1780--1781

PL

W artykule przedstawiono wyniki badań doświadczalnych obróbki EDM stali w roztworze nafty z płatkami grafenowymi oraz w dielektryku na bazie nafty. Wyznaczono wpływ rodzaju zastosowanego dielektryka na chropowatość obrobionych powierzchni. Stwierdzono, że modyfikacja właściwości dielektryka istotnie wpływa na proces erozji elektrycznej obrabianego materiału.

EN

The article presents results of experimental investigation EDM with graphene flakes in dielectric and pure kerosene. The relations between surface roughness and different kind of dielectric parameters have been determined. Modification of the properties of the dielectric has a significant impact on the process of electrical erosion of the workpiece.

4

Application of Taguchi design method to optimize the electrical discharge machining

Chen D.C., Jhang J.J., Guo M.W.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 57, nr 2

76--82

EN

Purpose: The current study utilizes the Taguchi design methodology to optimize the EDM processing parameters for the machining of A6061-T6 aluminum alloy. The experimental trials consider four EDM parameters, namely the pulse current (PC), the pulse-on duration (ON), the duty cycle (DC), and the machining duration (MD). Design/methodology/approach: The machined specimens are observed using the surface roughness is measured using a commercial profilometer. The optimal machining parameters and the relative influence of each parameter on the surface roughness are determined by analyzing the experimental data using the analysis of means (ANOM) and analysis of variance (ANOVA) techniques. Findings: The results show that the magnitude of the surface roughness is determined primarily by the pulse current (PC) and duty cycle (DC) parameters. A CuZn40 brass alloy specimen is machined using the optimal processing parameters and is found to have a lower mean surface roughness than the A6061-T6 workpiece. Research limitations/implications: Practical implications: The general applicability of the optimal machining parameters is investigated by machining a CuZn40 alloy specimen under the optimal conditions and then comparing the surface roughness characteristics of the machined surface with those of the A6061-T6 specimen. Originality/value: It is inferred that the optimal machining parameters established using the Taguchi design methodology have a good general applicability to the EDM machining of both aluminum and brass alloys.

5

Selected problems of electrical discharge machining (EDM) of metal composite materials applied in manufacturing of mechanical vehicles

Perończyk J.

Journal of KONES

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2011

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Vol. 18, No. 1

429-442

EN

The paper presents examples of applications for metal composite materials on Al matrix reinforced with ceramic particles in the form of grains, fibre or whiskers in the automotive industry. Highlighted are the advantages and drawbacks of such composite materials and issues involved in shaping complete parts. Presence of hard and brittle ceramic particles in the Al alloy (given their sufficient concentration) significantly impacts on the physical, chemical and mechanical properties of the material and its suitability for shaping complete parts and constituting a surface layer (SL) with required properties. In making metal composite materials of Al alloys, various (including the latest) methods of casting are applied, often in combination with press molding in semi-fluid state, as well as powder metallurgy (P/M) methods. The final machining of functionally significant surfaces is done by machining (by all ways and variants). With presence of more than 5% (by volume) ceramic reinforcing particles it becomes necessary to use cutting blades of the so-called super hard materials, including composites of polycristalline diamond and diamond. This considerably increases manufacturing costs. Electrical discharge machining has proved to be an effective way for shaping metal parts, in all its variants: sinker (EDM), wire erosion (WEDM), micromachining (ěEDM), shaping by free electrode (REDM), discharge grinding (AEDM) and other. Cited in the paper are the results of own research connected with EDM and WEDM of Al alloys composite cast and reinforced with particles of Al2O3 (AlSi7Mg + 20%Al2O3) and a composite material produced by powder metallurgy methods (P/M) reinforced with various (maximum 10%) concentrations of Al2O3 or SiC or Si3N4. EDM and WEDM technological characteristics were defined for the studied materials in the form of regressive dependencies as statistical models of given indicators allowing for defining impact of machining parameters on shaping the indicators. In addition, there are selected photos of metallographic structures, enabling observation and evaluation of surface layer phase changes and chemical composition after EDM. The highly enlarged SEM micro-photos which are included show the geometric structure of machined surface, micro-cracks on borders of the composite material grains, presence of minor reinforcement particles adhering to the surface. This confirms the complex nature of electrical discharge machining mechanism taking place locally after very high temperatures and in a very short time, in presence of cold dielectric.

6

Struktura geometryczna powierzchni ukonstytuowana w procesie obróbki elektroerozyjnej

Niemczewska-Wójcik M.

Tribologia

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2010

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nr 5

63-74

PL

Obróbka elektroerozyjna, należąca do tzw. niekonwencjonalnych metod obróbki materiałów, znalazła szerokie zastosowanie w kształtowaniu elementów wykonanych z materiałów trudnoskrawalnych oraz o złożonej geometrii. W pracy przedstawiono ogólną charakterystykę obróbki elektroerozyjnej. Analizie (ilościowej i jakościowej) poddano wyniki badań (mikroskop optyczny, elektronowy mikroskop skaningowy, profilometr) struktury geometrycznej powierzchni ukonstytuowanej w procesie obróbki elektroerozyjnej. Stwierdzono istotny wpływ parametrów obróbki na ukształtowanie powierzchni oraz jej jakość technologiczną.

EN

Electrical discharge machining, which belongs to the non-conventional group of machining methods is widely used for manufacturing elements made of hard materials and those having a complicated geometry. The paper gives an overview of electrical discharge machining. The author has conducted research (quantitative and qualitative) into the results of the surface geometric structure created by the electrical discharge machining process. For analysis purposes, an optical microscope, a scanning electron microscope, and a profilometer were used. It has been found that machining parameters have a significant influence on the shape and technological quality of a surface.

7

Testing of carbon fibres as tool electrodes in micro electrical discharge machining

Kudla L., Trych A.

Journal of Automation Mobile Robotics and Intelligent Systems

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2009

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Vol. 3, No. 4

153-156

EN

The aim of this paper is to present the outcomes of the experiments concerning micro electrical discharge machining with the use of carbon fibres as tool electrodes. Key properties of carbon fibres are discussed and the procedure of such electrodes fabrication is also described. Conducted tests indicate promising perspectives for machining with such electrodes by means of shaping microcavities, but at the same time they reveal problems. A longitudinal machining as well as experiments with different electric parameters were presented. Finally, the influence of discharge energy is being considered.

8

Konstytuowanie warstwy wierzchniej spieków FeAl+Al2O3 mikroobróbką elektroerozyjną

Durejko T., Zarański Z., Sulej S.

Kompozyty

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2008

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R. 8, nr 2

190-194

PL

Kompozyty na osnowie fazy międzymetalicznej FeAl umacniane cząstkami Al2O3 są postrzegane jako zamienniki dla obecnie stosowanych stopów żaroodpornych i żarowytrzymałych. Wytwarzanie tego typu materiałów tradycyjnymi metodami topienia i odlewania wiąże się ze stosowaniem dodatkowej, skomplikowanej obróbki cieplno-plastycznej, co znacznie wydłuża i podraża proces technologiczny. Prowadzone badania technologiczne kompozytów FeAl+Al2O3 wskazują na przydatność podczas ich wytwarzania technik z obszaru metalurgii proszków. Powoduje to jednak znaczne ograniczenia, jeśli chodzi o obróbkę końcową spieku. W tym przypadku jedną z metod kształtowania struktury warstwy wierzchniej może być obróbka elektroerozyjna. W badaniach prezentowanych w niniejszej pracy jako materiał badawczy wykorzystano kompozyty FeAl+Al2O3 otrzymane metodą dwuetapowego spiekania mieszaniny czystych technicznie proszków żelaza i aluminium. Właściwości warstwy wierzchniej kształtowano za pomocą zgrubnej i wykańczającej obróbki elektroerozyjnej drutem o średnicy 0,1 i 0,25 mm (WEDM). Przeanalizowano wpływ wariantów obróbki elektroerozyjnej na strukturę geometryczną warstwy wierzchniej. Na podstawie krzywej nośności wyznaczono parametry charakteryzujące badane spieki pod względem odporności na zużycie ścierne. Dodatkowo określono zmiany mikrostruktury w warstwie wierzchniej spieków.

EN

The iron aluminides FeAl have been among the most widely investigated intermetallics. For example, they have relatively low density, high stiffness, and excellent resistance to oxidation and corrosion at elevated temperature. Their major disadvantages is the susceptibility to environmental embrittlement at room temperature, very poor strength and creep resistance above 600° C. This problem can be partially solved by microalloying and oxide dispersion strengthening (ODS). The cost of manufacturing process is essential part of all costs, especially for new materials, so there are many trials to introduce unconventional solutions of processing or to modificate well known technologies, such powder metallurgy (PM). We proposed a PM process termed sintering at cyclic loading, as an alternative fabrication method, by which dense FeAl intermetallics were produced successfully from elemental powder mixtures with addition nanosize Al2O3. The FeAl+Al2O3 composite was obtained by two-stage sintering of elemental iron and aluminium powders with a 1% volumetric addition of nano-Al2O3. In the first stage of a processing, a powder charge was compacted/sintered under cyclically pressure. Structurally inhomogeneous powder compacts were then loosely sintered in argon atmosphere. The obtained sinters with composite structures were treated via two-variant (different wire diameter - 0.1 and 0.25 mm) roughing and finishing wire electrical discharge machining (WEDM). Sinters microstructure and surface texture (ST) after WEDM process were analyzed. On the base of measured roughness profiles a load capacity curve and quantitative parameters determining abrasive wear resistance of investigated sinters were found. Additionally, a 3D spatial roughness profile was registered for each sample. It was found that height of roughness after 0.25 mm wire finishing EDM is about one and a half time and three times lower than sinter roughness after 0.1 mm wire roughing and 0.1 mm wire finishing EDM, respectively.