An Experimental Study of the Phenomenon of Surface Alloying by EDM Process Using Inconel Tool Electrode

2013 ◽  
Author(s):  
Sanjeev Kumar
Keyword(s):  
Experimental Study ◽  
Surface Properties ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Plasma Channel ◽  
Machining Process ◽  
Tool Electrode ◽  
Electrode Wear ◽  
Surface Alloying ◽  
Machining Conditions

Electrical Discharge Machining (EDM) has emerged as a very important machining process due to its numerous advantages. It is extensively used by the die and toolmaking industry for the accurate machining of complex internal profiles. Although EDM is essentially a material removal process, it has been used successfully for improving the surface properties of the work materials after machining. As the dissolution of the electrode takes place during the process, some of its constituents may alloy with the machined surface under appropriate machining conditions. Additive powders in the dielectric medium may form part of the plasma channel in the molten state and produce similar alloying effect. The breakdown of the hydrocarbon dielectric under intense heat of the spark contributes carbon to the plasma channel. Sudden heating and quenching in the spark region also alters the surface properties. This paper reports the results of an experimental study into electrical discharge machining of H13 hot die steel with Inconel (an alloy of chromium, nickel and iron) tool electrode under machining conditions favouring high electrode wear. The results show improvement in micro-hardness after machining by as much as 88%. Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis of the machined surfaces show transfer of chromium and nickel from the tool electrode. Both these elements form intermetallic compounds as well as solid solution with iron and strengthen it. It was found that percentage of chromium increased from 5.39% to 6.52% and that of nickel increased from 0.19% to 4.87%. The favourable machining conditions for surface alloying were found to be low value of peak current, shorter pulse on-time, longer pulse off-time and negative polarity of the tool electrode.

The effect of magnesium content on drilling of Al-Mg-Ti alloy by hole electrical discharge machining process

2020 ◽  
Vol 235 (1-2) ◽  
pp. 125-133
Author(s):  
Omer Eyercioglu ◽  
Kursad Gov
Keyword(s):  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Magnesium Content ◽  
Machining Process ◽  
Electrode Wear ◽  
Ti Alloy ◽  
Ti Alloys ◽  
Mg Content

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.

Small Diameter External Cylindrical Surfaces Obtained by Ram Electrical Discharge Machining

2014 ◽  
Vol 611-612 ◽  
pp. 650-655 ◽  
Author(s):  
Laurenţiu Slătineanu ◽  
Margareta Coteaţă ◽  
Hans Peter Schulze ◽  
Oana Dodun ◽  
Irina Besliu ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Process Analysis ◽  
Electrical Discharge Machine ◽  
Small Diameter ◽  
Machining Process ◽  
Dielectric Fluid ◽  
Tool Electrode ◽  
Electrical Discharges ◽  
Pulse On Time

Electrical discharge machining uses the pulse electrical discharges generated between the closest asperities existing on the workpiece surface and the active surface of the tool electrode in dielectric fluid. Essentially, some distinct electrical discharge machining schemas could be used in order to obtain cylindrical external surfaces; within this research, one preferred a machining schema based on the use of a cooper plate in which there were small diameter holes, by taking into consideration the existence of a ram electrical discharge machine. The results of the machining process analysis were presented. A thin copper was considered to be used as tool electrode, in order to diminish the spurious electrical discharges, able to generate shape errors of the machined surface. Some experimental researches were developed by changing the sizes of the process input parameters. As output factors, the test piece and tool electrode masses decreases were considered. Power type empirical mathematical models were determined, in order to highlight the influence exerted by the pulse on time, off time and machining process duration on the output parameters values.

Experimental study of an electrostatic field–induced electrolyte jet electrical discharge machining process

2015 ◽  
Vol 231 (10) ◽  
pp. 1752-1759 ◽  
Author(s):  
Zhang Yaou ◽  
Han Ning ◽  
Kang Xiaoming ◽  
Zhao Wansheng ◽  
Xu Kaixian
Keyword(s):  
Electrostatic Field ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Electrochemical Machining ◽  
Machining Process ◽  
Cyclic Process ◽  
Tool Electrode ◽  
Series Of Experiments ◽  
Current Detection ◽  
Electrolyte Jet

In this study, a new electrostatic field–induced electrolyte jet electrical discharge machining method has been proposed, which can automatically generate the tool electrode. Then, a series of experiments have been carried out to reveal the machining mechanism and test the machining ability of this method. The continuous observation experiments and the online current detection experiments have demonstrated that the electrolyte jet discharge machining is a pulsing, dynamic and cyclic process. Moreover, the 20-min time long reverse polarity experiments on the silicon surface have revealed that the machining is an electrical discharge machining process during the negative polarity machining; however, in the positive polarity machining, it is a hybrid electrical discharge machining and electrochemical machining process. Furthermore, the craters as small as 2 µm in diameter on stainless steel and silicon are produced by this electrolyte jet electrical discharge machining, which has proved the micro-machining ability of this method.

Evaluation of Electrical Discharge Machining Performance on Al (6351)–SiC–B4C Composite

2019 ◽  
pp. 109-124
Author(s):  
Uthayakumar M. ◽  
Suresh Kumar S. ◽  
Thirumalai Kumaran S. ◽  
Parameswaran P.
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Research Work ◽  
Machining Process ◽  
Electrode Wear ◽  
Machining Parameters ◽  
Machining Performance ◽  
Machined Surface ◽  
Output Performance ◽  
B4c Particles

Electrical discharge machining (EDM) process is a non-conventional machining process used for the material which are difficult to machine. In this research work, an attempt has been made to determine the influence of Boron Carbide (B4C) particles on the machinablity of the Al (6351) alloy reinforced with 5 wt. % Silicon Carbide (SiC) Metal Matrix Composite (MMC) through EDM. Influence of machining parameters such as pulse current (I), pulse on time (Ton), duty factor (τ), and gap voltage (V) on affecting the output performance characteristics namely Electrode Wear Ratio (EWR), Surface Roughness (SR) and Power Consumption (PC) which are studied. The result shows that the addition of B4C particles significantly affects the machinablity of the composite, with a contribution of 1.6% on EWR, 3.5% on SR and 19.8% on PC. The crater, recast layer formation, and Heat Affected Zone (HAZ) in the machined surface of the composite are also reported in detail.

Research of the Basic Physical Regularities of Material Removal in Electrical Discharge Machining of Tool Steel

2017 ◽  
Vol 756 ◽  
pp. 96-106
Author(s):  
Ľuboslav Straka ◽  
Slavomíra Hašová
Keyword(s):  
Tool Steel ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Main Process ◽  
Tool Electrode ◽  
Electrode Wear ◽  
Workpiece Material ◽  
The Individual ◽  
Selection Of

The paper describes the basic physical regularities of material removal in Electrical discharge machining (EDM) of tool steel. One of the parameters, that material removal regularities quite accurately identifies, is the tool wear rate (TWR). This parameter, however, describes only the regularities concerning the tool electrode wear. More complex parameter for assessing regularities of material removal in EDM is thus electrode wear ratio (EWR). This parameter, except the size of the wear of the tool electrode, also describes the size of the workpiece material removal. Research on material removal was carried out on samples made out of tool steel EN X32CrMoV12-28 using Cu-ETP electrode EN CW004A. Aim of this paper was also based on the selection of main process parameters that significantly influence the material removal in EDM to define the individual specifics with regard to minimizing EWR.

Microstructure and Electrode Discharge Machining of TiN/Si3N4 Composites

2005 ◽  
Vol 475-479 ◽  
pp. 1337-1340
Author(s):  
Chien Cheng Liu ◽  
Jow Lay Huang
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Ceramic Composites ◽  
Tool Electrode ◽  
Electrode Wear ◽  
Micro Edm ◽  
Si3n4 Ceramic ◽  
Whole Process ◽  
Electrode Discharge ◽  
Scanning Electron

Conductive TiN/Si3N4 ceramic composites were processed by electrical discharge machining (EDM) and their microstructure and conductivity investigated. A low electrical resistivity of 1.25×10-3Ω.cm was obtained in 40vol%TiN/Si3N4 composite. The whole process of tool electrode wear is evaluated by sinker-EDM. The machined surfaces of TiN/Si3N4 ceramic composites were examined by scanning electron microscopy (SEM) and profilometry to determine the surface finish. Micropores of 700µm in depth and 70µm in diameter were successfully machined in TiN/ Si3N4 composites by the micro-EDM method.

Electrode Tool Wear at Electrical Discharge Machining

2012 ◽  
Vol 504-506 ◽  
pp. 1189-1194 ◽  
Author(s):  
Laurenţiu Slătineanu ◽  
Hans Peter Schulze ◽  
Oana Dodun ◽  
Margareta Coteaţă ◽  
Lorelei Gherman ◽  
...  
Keyword(s):  
Cross Section ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Experimental Tests ◽  
Machining Process ◽  
Electrode Wear ◽  
Electrical Discharges ◽  
Workpiece Material ◽  
Electrode Tool ◽  
Theoretical Considerations

As consequence of the development of electrical discharge machining process, the electrode is affected by wear; knowing the evolution of the electrode wear, a better estimation of its service life is possible. It is expected that the electrode wear depends on the energy of the electrical discharges and the mass of the electrode. It is known also that the nature of the workpiece material exerts influence on the evolution of the electrode wearing process. In the paper, some theoretical considerations are used to highlight the above mentioned aspects. A set of experimental tests was designed and developed in order to highlight the influence exerted by the nature of the workpiece material and by the size of the cross section of the electrode, respectively, on the electrode wear. Empirical mathematical models corresponding to the evolution of the electrode wear were established.

Study on electrical discharge machining for cemented carbide with non-flammable dielectric liquid: Influence of form of oxygen supplied to dielectric liquid on machining

2017 ◽  
Vol 232 (4) ◽  
pp. 568-577 ◽  
Author(s):  
Masahiro Yoshida ◽  
Yuu Ishii ◽  
Takemi Ueda
Keyword(s):  
Hydrogen Peroxide ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Dielectric Liquid ◽  
Cemented Carbide ◽  
Tool Electrode ◽  
Electrode Wear ◽  
Machining Speed ◽  
Machining Characteristics ◽  
Oil Type

One of the problems faced in the finish electrical discharge machining of cemented carbide is the slow machining speed due to frequent abnormal discharges and concentrated discharge. To resolve this problem, in this study, attempts were made to supply oxygen to oil-type non-flammable dielectric liquid used in finish electrical discharge machining. First, the effects of the form of the oxygen when it is supplied to the dielectric liquid were investigated. As a result, it was found that when oxygen is supplied to the machining gap in the microbubble state, machining is not affected at all. When dissolved in the dielectric liquid and supplied, machining speed was seen to improve. Next, machining experiments were conducted, varying the percentage of 35 wt% hydrogen peroxide water mixed with the dielectric liquid to change the amount of oxygen in the dielectric liquid. As a result, the following were clarified. (1) The machining speed was six times faster than normal dielectric liquid when 15 wt% of oxygen was mixed; (2) at this time, the tool electrode wear had decreased to one-fifth that of normal dielectric liquid; (3) the surface roughness obtained was below Ra 1 µm regardless of the mixed percentage of hydrogen peroxide water; and (4) better machining characteristics were obtained when the workpiece was set as the positive electrode.

scholarly journals Improving Machining Performance for Deep Hole Drilling in the Electrical Discharge Machining Process Using a Step Cylindrical Electrode

2021 ◽  
Vol 11 (5) ◽  
pp. 2084 ◽  
Author(s):  
Kamonpong Jamkamon ◽  
Pichai Janmanee
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Side Wall ◽  
Machining Process ◽  
Hole Drilling ◽  
Electrode Wear ◽  
Deep Hole ◽  
Cylindrical Electrode ◽  
Machining Performance ◽  
Deep Hole Drilling

The performance of electrical discharge machining for drilling holes decreases with machining depth because the conventional flushing and electrode cannot completely eliminate debris particles from the machining area. In this study, a modified electrode for self-flushing in the electrical discharge machining process with a step cylindrical shape was designed to improve machining performance for deep hole drilling. The experimental results of the step cylindrical electrode showed that the material removal rate increased by approximately 215.7%, 203.8%, and 130.4%, and the electrode wear ratio decreased by approximately 47.2%, 63.1%, and 37.3%, when compared with a conventional electrode for the diameters of 6, 9, and 12 mm, respectively. In addition, the gap clearance and concavity of the side wall of the drilled hole was reduced with the step cylindrical electrode. The limited high flank of the electrode led to an increase in the escape area of the debris that was partially removed from the machining area, and the limited secondary spark on the side wall of the electrode resulted in a reduction in machining time.

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