Ringing Effect and Reversed Current Analysis of RC-Pulse Generator in Electrical Discharge Machining

2013 ◽  
Vol 770 ◽  
pp. 183-188 ◽  
Author(s):  
Min Zhang ◽  
Qin He Zhang ◽  
De Zheng Kong ◽  
Xue Bai

RC-pulse generator has a simple structure and it is easy to be made and repaired. Especially RC-pulse generator can provide high frequency and low energy discharges. Therefore RC-pulse generators are used in micro-EDM field. But its high tool wear ratio and low efficiency restrict its applications. Ringing effect is considered to have effect on the defects. This research was done to study the ringing effect in electrical discharge. Taguchi method was used and discharge curves of voltage and current were recorded and analyzed. Ringing effect plays a key role in discharges and reversed current. A waveform model established with ringing effect theory is almost the same as the waveforms recorded in the experiment. Reversed current exists in almost a half time of discharge period which is the representation of ringing effect. Suitable process parameters can reduce reversed current and proper improvements could eliminate reversed current which will reduce the tool wear ratio and increase the efficiency in RC-pulse generator.

2017 ◽  
Vol 64 (2) ◽  
pp. 149-163 ◽  
Author(s):  
Govindan Puthumana

AbstractTo achieve better precision of features generated using the micro-electrical discharge machining (micro-EDM), there is a necessity to minimize the wear of the tool electrode, because a change in the dimensions of the electrode is reflected directly or indirectly on the feature. This paper presents a novel modeling and analysis approach of the tool wear in micro-EDM using a systematic statistical method exemplifying the influences of capacitance, feed rate and voltage on the tool wear ratio. The association between tool wear ratio and the input factors is comprehended by using main effect plots, interaction effects and regression analysis. A maximum variation of four-fold in the tool wear ratio have been observed which indicated that the tool wear ratio varies significantly over the trials. As the capacitance increases from 1 to 10 nF, the increase in tool wear ratio is by 33%. An increase in voltage as well as capacitance would lead to an increase in the number of charged particles, the number of collisions among them, which further enhances the transfer of the proportion of heat energy to the tool surface. Furthermore, to model the tool wear phenomenon, a regression relationship between tool wear ratio and the process inputs has been developed.


2013 ◽  
Vol 470 ◽  
pp. 585-588 ◽  
Author(s):  
Min Zhang ◽  
Qin He Zhang ◽  
De Zheng Kong ◽  
Yang Ren

Electro-arc machining is similar with traditional electrical discharge machining (EDM) while the pulse duration of electro-arc machining is longer than that of EDM. The longer discharge was named arcing, and the arcing could lead to high material remove rate (MRR) and low tool wear ratio (TWR). Processing factors including discharge medium, tool polarity, tool material, voltage and rotational speed were chosen as input parameters on MRR and TWR. Taguchis method was used to evaluate their effects. All of the five processing factors had effects on MRR and TWR. The effects and the mechanism are also discussed.


2012 ◽  
Vol 268-270 ◽  
pp. 82-86
Author(s):  
Jing Jing Zhang ◽  
Kai Yong Jiang ◽  
Jie Yan ◽  
Fei Wang ◽  
Xiao Wei Wang

This paper is to explore the feasibility of TiN/Cu-based composite materials as electrical discharge machining (EDM) electrodes.The tool wear ratio (TWR) of EDM electrode directly reflects the machining precision. To reduce the tool wear ratio(TWR) of Cu electrode in the EDM processing, Inorganic mixture of different content of ceramic materials TiN powder and Cu powder are prepared , then pressed and sintered into EDM electrodes.Experimental results show that: in the six batchs of experiments, the tool wear ratio (TWR) of 35%TiN/Cu electrode is the least, which is about 4.98%, much less than that of commercial copper electrode . The microstructures of the TiN/Cu electrodes after electrical discharge machining (EDM) as well are analyzed in this paper.


Author(s):  
Gurmail Singh Malhi ◽  
Gurpreet Singh Sokhal ◽  
Gurprinder Singh Dhindsa ◽  
Kamaljit Singh Sokhal

Electrical discharge machining (EDM) is used in die making and aerospace industries. This paper presents the performance study of the conventional EDM when used with powder mixed dielectric. Copper, graphite and mix (copper and graphite) were used. Pulse on, pulse off and current are the parameters which were varied at three levels. Copper, graphite and tungsten-copper were used as the electrode. The material removal rate and tool wear rate are assessed using design of experiments.


Author(s):  
Rahayu Mekar Bisono ◽  
Rifky Maulana Yusron

Electronic Discharge Machining (EDM) sinking applied widely in advance material manufacturing, every process parameter will count on this company. Their performance evaluated by some parameters such as surface roughness and tool wear ratio. Then they will be a dependent variable on this research. Independent variables on this research are electrode polarization, gap voltage, duty factor and pulse current.  Every variable has three levels, except electrode polarization has two levels. This research conducting using Taguchi matrix orthogonal L18 (21×33) methods. The aim of this experiment is to evaluate optimization parameter process on EDM sinking, using Taguchi-Grey-Fuzzy methods. Characteristics response optimal applied are ‘smaller better’ for surface response roughness and tool wear ratio. This research using DAC tool steel as work-piece. DAC is most widely used as die for aluminum and zinc die-casting. The aim of this research is finding contribution of variable in EDM sinking parameter. Result of this research show contribution from variable process to reduce variance total observed response simultaneously, in order are electrode polarization on 49,53%, gap voltage on 23,52%, duty factor on 5,45% and pulse current on 9,92%. From validated optimization in confirmation experiment, to conclude combination variable process optimal response value is electrode polarization on positive, gap voltage at 50V, duty factor at 0.5 and pulse current at 12A.   


2016 ◽  
Vol 40 (3) ◽  
pp. 331-349 ◽  
Author(s):  
S. Sivasankar ◽  
R. Jeyapaul

This research work concentrates on Electrical Discharge Machining (EDM) performance evaluation of ZrB2- SiC ceramic matrix composites with different tool materials at various machining parameters. Monolithic ZrB2 possesses lower relative density (98.72%) than composites. ZrB2 with 20 Vol.% of SiC possesses 99.74% of the relative density with improved hardness values. Bend strength and Young’s modulus increase with SiC addition until it reaches 20 Vol% and then decreasing. EDM performance on tool materials of tungsten, niobium, tantalum, graphite and titanium at various levels of pulse on time and pulse off time are analyzed. Graphite produces the best Material removal rate (MRR) for all the workpieces. Tool wear rate decreases with melting point and thermal conductivity of the tool material.


2021 ◽  
Author(s):  
Dragan Rodic ◽  
Marin Gostimirovic ◽  
Milenko Sekulic ◽  
Borislav Savkovic ◽  
Branko Strbac

Abstract It is well known that electrical discharge machining can be used in the processing of nonconductive materials. In order to improve the efficiency of machining modern engineering materials, existing electrical discharge machines are constantly being researched and improved or developed. The current machining of non-conductive materials is limited due to the relatively low material removal rate and high surface roughness. A possible technological improvement of electrical discharge machining can be achieved by innovations of existing processes. In this paper, a new approach for machining zirconium oxide is presented. It combines electrical discharge machining with assisting electrode and powder-mixed dielectric. The assisting electrode is used to enable electrical discharge machining of nonconductive material, while the powder-mixed dielectric is used to increase the material removal rate, reduce surface roughness, and decrease relative tool wear. The response surface method was used to generate classical mathematical models, analyzing the output performances of surface roughness, material removal rate and relative tool wear. Verification of the obtained models was performed based on a set of new experimental data. By combining these latest techniques, positive effects on machining performances are obtained. It was found that the surface roughness was reduced by 18%, the metal removal rate was increased by about 12% and the relative tool wear was reduced by up to 6% compared to electrical discharge machining with supported electrode without powder.


Author(s):  
Arun Kumar Rouniyar ◽  
Pragya Shandilya

Magnetic field assisted powder mixed electrical discharge machining is a hybrid machining process with suitable modification in electrical discharge machining combining the use of magnetic field and fine powder in the dielectric fluid. Aluminum 6061 alloy has found highly significance for the advanced industries like automotive, aerospace, electrical, marine, food processing and chemical due to good corrosion resistance, high strength-to-weight ratio, ease of weldability. In this present work, magnetic field assisted powder mixed electrical discharge machining setup was fabricated and experiments were performed using one factor at a time approach for aluminum 6061 alloy. The individual effect of machining parameters namely, peak current, pulse on time, pulse off time, powder concentration and magnetic field on material removal rate and tool wear rate was investigated. The effect of peak current was found to be dominant on material removal rate and tool wear rate followed by pulse on time, powder concentration and magnetic field. Increase in material removal rate and tool wear rate was observed with increase in peak current, pulse on time and a decrease in pulse off time, whereas, for material removal rate increases and tool wear rate decreases up to the certain value and follow the reverse trend with an increase in powder concentration. Material removal rate was increased and tool wear rate was decreased with increase in magnetic field.


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