Study the Effects of Dielectric Type on the Machining Characteristics of γ-Ti Al in Electrical Discharge Machining

Author(s):  
Mohammad Reza Shabgard ◽  
Hossein Faraji ◽  
Behnam Khosrozade ◽  
Hadi Eivazi-Bagheri ◽  
Keivan Amini

The current study surveys the results of using deionized water and kerosene as dielectrics in the machining outputs of γ-TiAl intermetallic compound obtained in electric discharge machining. Influences of these different dielectrics properties on machining speed, tool wear, surface cracks and roughness were compared. Scanning electron microscopy micrographs were prepared to investigate influences of dielectrics on the surface characteristics of electrically discharged samples. Results indicate which by kerosene dielectric; the material removal rate (MRR) is further compared to another one. But deionized water as dielectric causes higher tool wear ratio than kerosene dielectric. Electrical discharged samples in deionized water have higher surface roughness, in addition it contains surface cracks, whereas kerosene dielectric results better surface finish in low pulse current. According to XRD spectra electric discharge machining in deionized water and kerosene dielectrics produces Ti3 Al intermetallic compound on the produced surface.

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.


2020 ◽  
Vol 22 (1) ◽  
pp. 105-118 ◽  
Author(s):  
S. Nandhakumar ◽  
S. Sathish Kumar ◽  
K. Sakthivelu

AbstractElectric Discharge Machining (EDM) is a non-conventional machining process and has a larger extent of application in manufacturing industry due to its accuracy. EDM simply uses electrical spark between the tool and workpiece in presence of dielectric medium to erode the workpiece in controlled manner. Improving the material removal rate and decreasing the tool wear rate (TWR), achieving higher surface finish, reducing machining time and enhancing dimensional accuracy are the major areas of focus in electrical discharge machining (EDM) process of SS 317 grade steel. In this research work effort to reduce the tool wear rate is concentrated by comparing the machining performance of two distinct electrodes namely copper and brass. Each electrode has their unique machining capabilities and the experimental results were compared in-terms of tool wear rate (TWR), Metal Removal Rate (MRR) and Machining Time (TM). Input variables were optimized based on the experimental output responses to achieve optimal level of input variables.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 23
Author(s):  
Kashif Ishfaq ◽  
Muhammad Asad ◽  
Saqib Anwar ◽  
Catalin I. Pruncu ◽  
Mustafa Saleh ◽  
...  

Titanium alloys, especially Ti-6Al-4V, which is considered a difficult-to-cut material, bears numerous applications in aerospace and biomedical sectors. The criticality of the accurate formation of the machined cavity for the said applications and properties of Ti-6Al-4V accentuated the use of electric discharge machining (EDM). However, the issues of lower material removal rate (MRR) and tool wear (TWR) discouraged the use of EDM. These inherent issues hold a pivotal role regarding the sustainable machining of Ti-alloy. Therefore, in this research the potentiality of kerosene-based dielectric, having graphene nanoparticles, is comprehensively examined for the sustainable EDM of Ti-6Al-4V, which was not focused upon yet. Experimentation was performed under Taguchi’s design (L18) with three types of electrodes, namely Aluminum, Brass and Copper. In total, 36 experiments were conducted, of which 18 were with graphene-mixed dielectric and the remaining were with kerosene. Experimental results reveal that the brass electrode with negative tool polarity yields higher MRR for both types of dielectrics. The maximum MRR (7.602 mm3/min) achieved with graphene mixed dielectric is 64.5% greater as compared to that obtained with kerosene (4.621 mm3/min). Moreover, the minimum TWR obtained for graphene-based dielectric, i.e., 0.17 mg/min is approximately 1.5 times less than that achieved with kerosene.


2016 ◽  
Vol 861 ◽  
pp. 20-25 ◽  
Author(s):  
Kan Wang ◽  
Qin He Zhang ◽  
Qing Yu Liu ◽  
Min Zhang ◽  
Jian Hua Zhang ◽  
...  

In this paper, experiments were conducted to investigate the effects of cylindrical electrode and helical electrode on the micro electrical discharge machining (EDM) performances during micro-hole machining of titanium alloy. The results show that the material removal rate (MRR) and the tool wear rate (TWR) increase with open circuit voltage, regardless of electrode shapes. Compared to the cylindrical electrode, helical electrode can result in higher MRR and lower relative tool wear ratio (RTWR). It can be concluded that the helical electrode is more suitable than cylindrical electrode for machining micro parts.


2020 ◽  
Vol 38 (9A) ◽  
pp. 1406-1413
Author(s):  
Yousif Q. Laibia ◽  
Saad K. Shather

Electrical discharge machining (EDM) is one of the most common non-traditional processes for the manufacture of high precision parts and complex shapes. The EDM process depends on the heat energy between the work material and the tool electrode. This study focused on the material removal rate (MRR), the surface roughness, and tool wear in a 304 stainless steel EDM. The composite electrode consisted of copper (Cu) and silicon carbide (SiC). The current effects imposed on the working material, as well as the pulses that change over time during the experiment. When the current used is (8, 5, 3, 2, 1.5) A, the pulse time used is (12, 25) μs and the size of the space used is (1) mm. Optimum surface roughness under a current of 1.5 A and the pulse time of 25 μs with a maximum MRR of 8 A and the pulse duration of 25 μs.


Author(s):  
Balbir Singh ◽  
Jatinder Kumar ◽  
Sudhir Kumar

This paper presents the experimental investigation on the electro-discharge machining of aluminum alloy 6061 reinforced with SiC particles using sintered Cu–W electrode. Experiments have been designed as per central composite rotatable design, using response surface methodology. Machining characteristics such as material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR) have been investigated under the influence of four electrical process parameters; namely peak current, pulse on time, pulse off time, and gap voltage. The process parameters have been optimized to obtain optimal combination of MRR, EWR, and SR. Further, the influence of sintered Cu–W electrode on surface characteristics has been analyzed with scanning electron microscopy, energy dispersive spectroscopy, and Vicker microhardness tests. The results revealed that all the process parameters significantly affect MRR, EWR, and SR. The machined surface properties are modified as a result of material transfer from the electrode. The recast layer thickness is increased at higher setting of electrical parameters. The hardness across the machined surface is also increased by the use of sintered Cu–W electrode.


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