scholarly journals Electrical Discharge Machining Non-Conductive Ceramics: Combination of Materials

Technologies ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 32 ◽  
Author(s):  
Marina A. Volosova ◽  
Anna A. Okunkova ◽  
Sergey V. Fedorov ◽  
Khaled Hamdy ◽  
Mariya A. Mikhailova
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Chemical Properties ◽  
Specific Electrical Conductivity ◽  
Dielectric Fluid ◽  
Working Zone ◽  
Plasma Sintering ◽  
Interelectrode Gap ◽  
Conductive Additives ◽  
Conductive Ceramics

One of the promising processing methods for non-conductive structural and functional ceramics based on ZrO2, Al2O3, and Si3N4 systems is electrical discharge machining with the assistance of an auxiliary electrode that can be presented in the form of conductive films with a thickness up to 4–10 µm or nanoparticles - granules, tubes, platelets, multidimensional particles added in the working zone as a free poured powder the proper concentration of which can be provided by ultrasound emission or by dielectric flows or as conductive additives in the structure of nanocomposites. However, the described experimental approaches did not reach the production market and industry. It is related mostly to the chaotic development of the knowledge and non-systematized data in the field when researchers often cannot ground their choice of the material for auxiliary electrodes, assisting powders, or nano additives or they cannot explain the nature of processes that were observed in the working tank during experiments when their results are not correlated to the measured specific electrical conductivity of the electrodes, particles, ceramic workpieces or nanocomposites but depends on something else. The proposed review includes data on the main electrophysical and chemical properties of the components in the presence of heat when the temperature in the interelectrode gap reaches 10,000 °C, and the systematization of data on ceramic pressing methods, including spark plasma sintering, the chemical reactions that occur in the interelectrode gap during sublimation of primary (brass and copper) and auxiliary electrodes made of transition metals Ti, Cr, Co, and carbon, auxiliary electrodes made of metals with low melting point Zn, Ag, Au, Al, assisting powder of oxide ceramics TiO2, CeO2, SnO2, ITO, conductive additives Cu, W, TiC, WC, and components of Al2O3 and Zr2O workpieces in interaction with the dielectric fluid - water and oil/kerosene medium.

scholarly journals On Adaptive Control for Electrical Discharge Machining Using Vibroacoustic Emission

Technologies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 96 ◽  
Author(s):  
Yury Melnik ◽  
Mikhail Kozochkin ◽  
Artur Porvatov ◽  
Anna Okunkova
Keyword(s):  
Adaptive Control ◽  
Control System ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Hard Alloys ◽  
Monitoring And Control ◽  
Working Zone ◽  
Conductive Ceramics ◽  
And Control ◽  
Adequate Data

The article is related to the research of the parameters of vibroacoustic emission for development of the monitoring and adaptive control system for electrical discharge machining. The classical control system based on a response of electrical parameters does not give an adequate data in the cases of a new class of materials processing as conductive ceramics reinforced by conductive nano additives and carbon nanotubes and whiskers. The idle pulses, which are working on the destruction of the erosion products in the gap, count as working pulses. The application of the monitoring and control tools based on vibroacoustic emission gives adequate data about conditions in the working zone. The developed system is available to count only impulses involved in working on the destruction of the workpiece. The experiments were conducted on the samples of materials with a low melting point as austenitic steel and aluminum alloy, and hard alloys. The records of vibroacoustic signals were analyzed for detection of the monitoring and adaptive control criteria.

scholarly journals Experimental Investigation of Stability of Vegetable Oils Used as Dielectric Fluids for Electrical Discharge Machining

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1187
Author(s):  
Maria-Crina Radu ◽  
Raluca Tampu ◽  
Valentin Nedeff ◽  
Oana-Irina Patriciu ◽  
Carol Schnakovszky ◽  
...  
Keyword(s):  
Vegetable Oils ◽  
Electrical Discharge ◽  
Structural Changes ◽  
Unsaturated Fatty Acids ◽  
Electrical Discharge Machining ◽  
Health And Safety ◽  
Chemical Properties ◽  
Dielectric Fluid ◽  
Dielectric Fluids ◽  
Qualitative Performance

One main drawback of electrical discharge machining (EDM) is related to the dielectric fluid, since it impacts both the environment and operator health and safety. To resolve these issues, recent research has demonstrated the technical feasibility and qualitative performance of vegetable oils as substitutes for hydrocarbon-based dielectric and synthetic oils in EDM. However, due to the higher content of unsaturated fatty acids, vegetable oils lose their stability, due to several factors such as heating or exposure to light or oxygen. The present study is a first attempt to analyze the extent to which the physic-chemical properties of vegetable oils change during EDM processing. Refractive index, dynamic viscosity and spectra analyses were conducted for sunflower and soybean oils. The results revealed that, under the applied processing conditions, no structural changes occurred. These findings are very promising from the perspective of EDM sustainability.

An extensive review on sustainable developments of dry and near-dry electrical discharge machining processes

2021 ◽  
pp. 1-37
Author(s):  
Sampath Boopathi
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Optimization Techniques ◽  
Machining Process ◽  
Working Fluid ◽  
Dielectric Fluid ◽  
Extensive Literature ◽  
Machining Processes ◽  
Research Activities ◽  
Dry Edm

Abstract Electrical discharge machining (EDM) is very essential unconventional electro-thermal machining process to machine the contour profile of hard materials in modern production industries. The liquid dielectric fluid has been replaced by the gas and minimum quantity of liquid mixed with gas (gas-mist) to encourage the green machining processes. The various gases and gas-mist have been used as the working fluid in dry and near-dry EDM respectively. The research-contextual, various dielectric fluids, sustainable and innovative developments, process parameters, machining characteristics, and optimization techniques applied in various dry and near-dry EDM have been illustrated through an extensive literature survey. Future research opportunities in both dry and near-dry EDM have been summarized to promote eco-friendly EDM research activities.

Surfactant and graphite powder–assisted electrical discharge machining of titanium alloy

2016 ◽  
Vol 231 (4) ◽  
pp. 641-657 ◽  
Author(s):  
Murahari Kolli ◽  
Adepu Kumar
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Graphite Powder ◽  
Recast Layer ◽  
Dielectric Fluid ◽  
Recast Layer Thickness

Surfactant and graphite powder–assisted electrical discharge machining was proposed and experiments were performed on titanium alloy in this investigation. Analysis was carried out to observe changes in dielectric fluid behaviour, material removal rate, surface roughness, recast layer thickness, surface topography and energy-dispersive X-ray spectroscopy. It was found out that the addition of surfactant to dielectric fluid (electrical discharge machining oil + graphite powder) improved the material removal rate and surface roughness. It was noticed to have reduced the recast layer thickness and agglomeration of graphite and sediment particles. Biface material migrations between the electrode and the workpiece surface were identified, and migration behaviour was powerfully inhibited by the mixing of surfactant. Surfactant added into dielectric fluid played an important role in the discharge gap, which increased the conductivity, and suspended debris particles in dielectric fluid reduced the abnormal discharge conditions of the machine and improved the overall machining efficiency.

scholarly journals On Electrical Discharge Machining of Non-Conductive Ceramics: A Review

Technologies ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 55 ◽  
Author(s):  
Marina Volosova ◽  
Anna Okunkova ◽  
Pavel Peretyagin ◽  
Yury A. Melnik ◽  
Natalya Kapustina
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Secondary Phase ◽  
Scientific Revolutions ◽  
Relevant Today ◽  
Potential Applications ◽  
Conductive Ceramics ◽  
3D Printed ◽  
Full Shift

The inability of ceramic and nanoceramic processing without expensive diamond tools and with a high-material-removal rate hampers the scope of its potential applications and does not allow humanity to make a full shift to the sixth technological paradigm associated with Kuhn scientific revolutions and Kondratieff’s waves and restrains the growth of the economy. The authors completed a review on the research state of ceramic and nanoceramic processing by electrical discharge machining, which is possibly solved by two principal approaches associated with the usage of standard commercially available machine tools. The first approach is related to the introduction of expensive secondary phase; the second approach proposes initiate processing by adding auxiliary electrodes in the form of coating, suspension, aerosol, or 3D-printed layer based on the components of silver, copper, or graphite in combination with an improved dielectric oil environment by introducing graphite or carbon nanoparticles, which is hugely relevant today.

scholarly journals Parametric optimization of wire cut electrical discharge machining

2014 ◽  
Vol 3 (2) ◽  
pp. 212
Author(s):  
M. Durairaj ◽  
A.K.S. Ansari ◽  
M. H. Gauthamkumar
Keyword(s):  
Surface Roughness ◽  
Orthogonal Array ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Fluid Pressure ◽  
Performance Criteria ◽  
Dielectric Fluid ◽  
Machining Parameters ◽  
Pulse On Time ◽  
Pulse Off Time

Wire Electrical Discharge Machining is a manufacturing process whereby a desired shape is obtained using electrical discharges (or) by repetitive spark cycle. Precision and intricate machining are the strengths. Machining parameters tables provided by the machine tool manufacturers often do not meet the operator requirements. Selection of optimum machining and machining parameters combinations is needed for obtaining higher cutting efficiency and accuracy. In this present study, machining is done using Wire-Cut EDM and optimization of surface roughness is done using Taguchis design of experiments. Experimentation was planned as per Taguchis L16 orthogonal array. Each experiment has been performed under different cutting conditions of gap voltage, pulse ON time, and pulse OFF time and Wire feed. Dielectric fluid pressure, wire speed, wire tension, resistance and cutting length are taken as fixed parameters. Inconel 800 was selected as a work material to conduct the experiments. From experimental results, the surface roughness was determined for each machining performance criteria. Signal to noise ratio was applied to measure the performance characteristics deviating from the actual value. Finally, experimental confirmation was carried out to identify the effectiveness of this proposed method. Keywords: Optimization; Taguchis L-16 Orthogonal Array; Surface Roughness; S/N Ratio.

Control Strategy for Electrical Discharge Machining (EDM) Pulse Power Generator

2014 ◽  
Vol 554 ◽  
pp. 643-647 ◽  
Author(s):  
Minhat Ade Erawan ◽  
Khamis Nor Hisham ◽  
Azli Yahya ◽  
Andromeda Trias ◽  
Juli Purwanto Nugroho Kartiko ◽  
...  
Keyword(s):  
Power Supply ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Pulse Power ◽  
Dielectric Fluid ◽  
Hard Material ◽  
Machining Processes ◽  
Power Generator ◽  
Pulse Power Generator ◽  
Control Feedback

Electrical Discharge Machining (EDM) is a advanced machine that can control electrical spark to erode metal on the workpiece. In manufacturing, EDM is used on hard material parts that are extremely difficult to machine by conventional machining processes. EDM system consists of a shaped tool and the work piece, which are connected to a power supply and placed in a dielectric fluid. EDM pulse power generator applies voltage and current pulses between the electrode and workpiece to generate sparks through the gap. To obtain the optimum metarial removal rate (MRR), a good alternative is to improve the gap voltage and gap current. A proposed solution to these issue is combining ultracapacitor bank to the main power supply circuit for EDM machines. The control feedback of this research is designed to make sure that the current on DC bus is maintained at current setting during the machining processes.

Influence of Pulse-on-Time on the Performance of Wire Electrical Discharge Machining of Ti-6Al-4V Using Zinc Coated Brass Wire

2014 ◽  
Vol 592-594 ◽  
pp. 416-420 ◽  
Author(s):  
Singaravelu D. Lenin ◽  
A. Uthirapathi ◽  
Ramana Reddy P.S. Venkata ◽  
Muthukannan Durai Selvam
Keyword(s):  
Surface Roughness ◽  
Electrical Discharge ◽  
Metal Removal ◽  
Electrical Discharge Machining ◽  
Kerf Width ◽  
Dielectric Fluid ◽  
Wire Electrical Discharge Machining ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Brass Wire

The present paper describes the influence of pulse-on-time on performance features such as Metal Removal Rate (MRR), Kerf width, Surface Roughness (SR) on cutting Titanium alloy (Ti-6Al-4V) in wire electrical discharge machining (WEDM) using zinc coated brass wire. The deionised water is used as dielectric fluid. The process parameters such as wire tension, wire speed, flushing pressure, discharge current, sparking voltage and pulse off time have kept constant at appropriate values throughout the experiment and the pulse on time is varied at nine different intervals. It was found that pulse-on-time is the most significant factor which greatly influences MRR, kerf width, and SR. It was also observed that taper at the end of cutting zone which is unavoidable occurrence for the machined part. This is due to the erosion of wire material. The surface roughness increases with increase in pulse on time also with higher rate of MRR.

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