Modeling of Active Gap Capacitance Electrical Discharge Machining

Author(s):  
Xiangzhi Wang ◽  
Hun Guo ◽  
Jiyuan Tu ◽  
Songlin Ding

Abstract Active gap capacitance electrical discharge machining (AGC-EDM) is a high-speed EDM method for machining polycrystalline diamond tools utilizing the active capacitive effect and powder mixing effect formed by the kerosene dielectric added with graphene particles. The capacitive effect increases the discharge energy and explosive force, which in turn influences the material removal efficiency; the powder mixed effect changes the states of dielectric and forms a non-fixed gap discharge process. Take into account these two aspects, a new discharge mechanism of AGC-EDM is proposed to describe the discharge process. Capacitance characteristics and chain stacking process of graphene-kerosene dielectrics are verified by experimental results. The material removal rate, relative electrode wear and surface roughness are discussed with the pulse duration, peak current, and graphene concentration to study the theories of the new EDM process.

Author(s):  
Omer Eyercioglu ◽  
Kursad Gov

This study presents an experimental investigation of small hole electrical discharge machining of Al-Mg-Ti alloys. A series of drilling operations were carried out for exploring the effect of magnesium content. Holes of 2 mm diameter and 15 mm depth were drilled using tubular single-hole rotary brass electrodes. The rates of material removal and electrode wear, surface roughness, overcut, average recast layer thickness, taper height and angle were studied for Al-Mg-Ti alloys contain 2%, 4%, 6%, 8%, 10%, 12%, and 14% Mg. The results show that the material removal rate is increasing with increasing Mg content while the rate of electrode wear is almost unchanged. Due to decreasing the melting temperature of the Al-Mg-Ti alloy with increasing Mg content, more metal melts and vaporizes during electrical discharge machining drilling. Therefore, more overcut and taper, thicker white layer, and rougher surfaces were measured for higher Mg content.


Author(s):  
Jin Zhang ◽  
Fuzhu Han

Abstract This paper proposed a new method of high-speed electrical discharge machining (EDM) using rotating short arcs under composite field. By the Lorentz force, the electric force and the high-speed rotation of the tool electrode, rotating short arcs are generated between the tool electrode and the workpiece, which can greatly improve the material removal rate of difficult-to-cut materials such as titanium alloys and superalloys. Firstly, the machining equipment used to generate rotating short arcs was constructed. Secondly, single arc discharge experiment was carried out to investigate the motion characteristics of rotating short arcs. The result shows that the arcs can rotate between the tool electrode and workpiece under composite field. Then, the experiment of processing GH4169 was conducted to explore the machining characteristics of rotating short arcs milling, which indicated that rotating short arcs can achieve a much higher material removal rate (MRR). Additionally, it’s found that the magnetic field also has influence on debris, which is beneficial to debris removal. Finally, a comparative experiment was carried out. The MRR of rotating short arcs milling was three times than that of traditional EDM, and the tool electrode wear rate (TEWR) is only one-fifth of that of traditional EDM. The comparative experiment further verified that rotating short arcs milling can achieve higher MRR and lower TEWR.


2009 ◽  
Vol 83-86 ◽  
pp. 672-679 ◽  
Author(s):  
Suleiman Abdulkareem ◽  
Ahsan Ali Khan ◽  
Mohamed Konneh

In electrical discharge machining (EDM), material is removed by a series of electrical discharge between the electrode (tool) and the workpiece that develops a temperature of about 8,0000C to 12,0000C. Due to high temperature of the sparks, work material is melted and vapourized, at the same time the electrode material is also eroded by melting and vapourization. Electrodes wear (EW) process is quite similar to the material removal mechanism as the electrode and the workpiece are considered as a set of electrode in EDM. In the present study effort has been made to reduce EW by cooling, using liquid nitrogen during the EDM of titanium alloy. Investigation on the effect of cooling on electrode wear (EW), material removal rate (MRR) and surface roughness (Ra) of the workpiece was carried out. Current (I), pulse on-time (ton), pause off-time (toff) and voltage (v) were considered as the machining parameters. Design of experiment (DOE) was used to design the experimental works. Cooling of electrode by this technique reduced the melting and vapourization of electrode material and enhances electrode life. It was possible to reduce EW up to 27% by applying this technique while MRR and Ra were improved by 18% and 8% respectively.


2015 ◽  
Author(s):  
Tianfeng Zhou ◽  
Lizheng Ma ◽  
Siqin Pang ◽  
Zhiqiang Liang ◽  
Xibin Wang

Basic experiments are carried out to analyze the size effects on the material removal rate (MRR), electrode wear rate (EWR) and relative loss rate (RLR) in the process of electrical discharge machining (EDM). Then, the relative loss rate is taken as the main criterion to decide the optimal cylindrical electrode size, which is applied to the design of the ring–shaped electrode. Finally, the advantages of the ring–shaped electrode are confirmed by comparing with the traditional plate-shaped electrode in the die-sinking electrical discharge machining experiments.


Mathematics ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 922 ◽  
Author(s):  
C. J. Luis Pérez

Technological tables are very important in electrical discharge machining to determine optimal operating conditions for process variables, such as material removal rate or electrode wear. Their determination is of great industrial importance and their experimental determination is very important because they allow the most appropriate operating conditions to be selected beforehand. These technological tables are usually employed for electrical discharge machining of steel, but their number is significantly less in the case of other materials. In this present research study, a methodology based on using a fuzzy inference system to obtain these technological tables is shown with the aim of being able to select the most appropriate manufacturing conditions in advance. In addition, a study of the results obtained using a fuzzy inference system for modeling the behavior of electrical discharge machining parameters is shown. These results are compared to those obtained from response surface methodology. Furthermore, it is demonstrated that the fuzzy system can provide a high degree of precision and, therefore, it can be used to determine the influence of these machining parameters on technological variables, such as roughness, electrode wear, or material removal rate, more efficiently than other techniques.


2011 ◽  
Vol 496 ◽  
pp. 247-252 ◽  
Author(s):  
Ruben Gil ◽  
J.A. Sánchez ◽  
N. Ortega ◽  
S. Plaza ◽  
B. Izquierdo ◽  
...  

Abstract. This paper analyses the technological capabilities of a novel rotary (EDM) electrical discharge machining process for the manufacturing of high aspect ratio cylindrical micro-components. The process is called Inverse Electrical Discharge Grinding (ISEDM). An experimental analysis has been carried out on high speed steel (tool steel Vanadis 23), using a conventional EDM machine and graphite electrode. The effect of pulse off-time, work piece final diameter and machining length on material removal rate, electrode wear ratio, radial accuracy and surface roughness has been quantified. From the study, optimum strategies that involve the use of different EDM regimes for achieving the optimum requirements can be defined. Micro-pins of 0.3 mm diameter with aspect ratio as high as 100:1 have been successfully manufactured.


2006 ◽  
Vol 315-316 ◽  
pp. 81-84 ◽  
Author(s):  
Qin He Zhang ◽  
Jian Hua Zhang ◽  
Q.B. Zhang ◽  
Shu Peng Su

Ultrasonic vibration aided electrical discharge machining (UEDM) in gas is an electrical discharge machining (EDM) technology, in which gases such as air and oxygen are used as dielectrics and ultrasonic vibration is applied. UEDM in gas can avoid environment pollution, the most serious disadvantage of conventional EDM in kerosene-based oil or other dielectric fluids, and it is environmental-friendly. The technology also possesses virtues of wide applications, high machining efficiency and simple tool electrodes and so on. The principle of UEDM in gas is introduced in this paper. Experiments have been carried out to study the effects of machining parameters on material removal rate (MRR), surface roughness of the workpiece and tool electrode wear ratio (TWR), and the experiments results have also been analyzed.


ROTASI ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 1
Author(s):  
Petrus Londa

Electrical Discharge Machining (EDM) adalah non-conventional machining process. EDM dapat memotong semua jenis benda kerja yang bersifat penghantar listrik, terutama digunakan pada benda kerja yang sangat keras dan memiliki bentuk yang rumit, yang tidak dapat dipotong oleh mesin konvensional. Penelitian ini menggunakan metode Taguchi untuk menentukan variabel pemesinan yang secara signifikan mempengaruhi proses pemotongan pada beberapa material elektroda (tembaga, kuningan, alumunium) dan benda kerja dari bahan K460 (amutit S). Taguchi L25 Orthogonal standard arrays dan analysis of variance (ANOVA) dapat menentukan performa variabel pemotongan (PON, POFF, GAP, QDON, SERVO dan LT) dengan variabel yang diteliti adalah Electrode Wear Rate (EWR), Material Removal Rate (MRR) dan Diameter Overcut (DOC). Hasil dari penelitian ini ditampilkan dalam bentuk tabel-tabel dan grafik yang menunjukan variabel pemesinan yang signifikan mempengaruhi proses pemotongan sesuai dengan jenis material elektroda yang digunakan.


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