EFFECT OF THE TOOL SURFACE AREA AND WORKPIECE VIBRATION ON THE μEDM PERFORMANCE

2021 ◽  
pp. 2150083
Author(s):  
DEEPAK RAJENDRA UNUNE

This work investigates the influence of tool surface area (TSA) on the average surface roughness ([Formula: see text], tool wear rate (TWR) and material removal rate (MRR) in the micro-electrical discharge machining ([Formula: see text]EDM). The effects of three different TSAs were investigated at three different discharge energy settings. It was observed that the TSA had substantial influence on [Formula: see text]EDM performance owing to scaling effect. Therefore, the low-frequency workpiece vibration was applied to improve the [Formula: see text]EDM performance. The surface topography of machined surfaces was examined using scanning electron microscopy to disclose the effect of TSA as well as vibration frequency on [Formula: see text]EDMed surfaces.

Author(s):  
Gurpreet Singh ◽  
DR Prajapati ◽  
PS Satsangi

The micro-electrical discharge machining process is hindered by low material removal rate and low surface quality, which bound its capability. The assistance of ultrasonic vibration and magnetic pulling force in micro-electrical discharge machining helps to overcome this limitation and increase the stability of the machining process. In the present research, an attempt has been made on Taguchi based GRA optimization for µEDM assisted with ultrasonic vibration and magnetic pulling force while µEDM of SKD-5 die steel with the tubular copper electrode. The process parameters such as ultrasonic vibration, magnetic pulling force, tool rotation, energy and feed rate have been chosen as process variables. Material removal rate and taper of the feature have been selected as response measures. From the experimental study, it has been found that response output measures have been significantly improved by 18% as compared to non assisted µEDM. The best optimal combination of input parameters for improved performance measures were recorded as machining with ultrasonic vibration (U1), 0.25 kgf of magnetic pulling force (M1), 600 rpm of tool rotation (R2), 3.38 mJ of energy (E3) and 1.5 mm/min of Tool feed rate (F3). The confirmation trail was also carried out for the validation of the results attained by Grey Relational Analysis and confirmed that there is a substantial improvement with both assistance applied simultaneously.


Author(s):  
Sagil James ◽  
Sharadkumar Kakadiya

Shape Memory Alloys are smart materials that tend to remember and return to its original shape when subjected to deformation. These materials find numerous applications in robotics, automotive and biomedical industries. Micromachining of SMAs is often a considerable challenge using conventional machining processes. Micro-Electrical Discharge Machining is a combination of thermal and electrical processes, which can machine any electrically conductive material at micron scale independent of its hardness. It employs dielectric medium such as hydrocarbon oils, deionized water, and kerosene. Using liquid dielectrics has adverse effects on the machined surface causing cracking, white layer deposition, and irregular surface finish. These limitations can be minimized by using a dry dielectric medium such as air or nitrogen gas. This research involves the experimental study of micromachining of Shape Memory Alloys using dry Micro-Electrical Discharge Machining process. The study considers the effect of critical process parameters including discharge voltage and discharge current on the material removal rate and the tool wear rate. A comparison study is performed between the Micro-Electrical Discharge Machining process with using the liquid as well as air as the dielectric medium. In this study, microcavities are successfully machined on shape memory alloys using dry Micro-Electrical Discharge Machining process. The study found that the dry Micro-Electrical Discharge Machining produces a comparatively better surface finish, has lower tool wear and lesser material removal rate compared to the process using the liquid as the dielectric medium. The results of this research could extend the industrial applications of Micro Electrical Discharge Machining processes.


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.


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.


Author(s):  
Qingyu Liu ◽  
Qinhe Zhang ◽  
Min Zhang ◽  
Jianhua Zhang

The material removal process of micro electrical discharge machining is based on the instantaneous ultra-high temperature generated by a series of repetitive discharge pulses. Due to the size effects, the polycrystal cannot be considered as continuous and homogeneous material when machining is in micron scale, and the effects of material microstructure should not be neglected. In this article, the thermoelectric characteristics of grain and grain boundary are discussed, and the influence of grain size on the machining performances in micro electrical discharge machining is researched. Two kinds of austenitic stainless steels (AISI 304) which are different in grain size are chosen as the workpieces in experiments. It is verified by both theory models and experimental results that the smaller the grain size, the higher the material removal rate, under the same discharge conditions. Both thermal conductivity and melting point of the grain boundary are lower than those of the grain because of the grain boundary segregation. The effective thermal conductivity and local effective melting point of polycrystalline materials vary with their grain sizes since the grain boundary volume fractions change. As a consequence, the material removal rate of micro electrical discharge machining has direct relationship with grain size of the workpiece.


Author(s):  
S. Nallusamy

Electrical Discharge Machining is a machining method primarily used for hard metals or those that are impossible to be machined with traditional techniques. The experimental investigation of material removal rate and tool wear rate during machining of oil hardened non-shrinking steel with brass and copper electrodes using EDM machine was carried out in this paper. This investigation presents the analysis and evaluation of heat affected zones and surface finish of the work piece using different tool electrodes and varying the machine parameters. The commercial grade kerosene oil has been used as dielectric fluid. The effect of various important EDM parameters such as discharge current (Ip) 2 to12A, pulse duration (Ton and Toff) and sparking voltage (V) of 80±5% have been used to yield the response in terms of Material Removal Rate (MRR) and Tool Wear Rate (TWR). Further a detailed analysis of the heat affected regions was also been carried out by using scanning electron microscopy.


2019 ◽  
Vol 1 (2) ◽  
pp. 105-112
Author(s):  
Nafsan Upara ◽  
Dimas Anugrah Destianto

Electrical Discharge Machining (EDM) merupakan pemesinan nonkonvensional yang memanfaatkan proses konversi listrik dan panas, dimana energi listrik digunakan untuk memunculkan loncatan bunga api dan proses pelepassan bahan terjadi akibat energi panas yang ditimbulkan dari bunga api tersebut.Keausan elektroda pada proses EDM die sinking merupakan peristiwa yang tidak dapat di hindari, namun dengan mengatur parameter pemotongan yang sesuai, diharapkan keausan yang terjadi pada elektroda se-minim mungkin dan pemakanan benda kerja semaksimal mungkin sehingga didapati tingkat akurasi ukuran pada benda kerja. Pada penelitian ini menggunakan metode Taguchi  dengan L8 orthogonal array memakai elektroda bahan tembaga dan benda kerja material SKS 3. S/N ratio dan ANOVA menentukan performa parameter proses EDM dengan respon yang di teliti adalah Material Removal Rate (MRR) dan Tool Wear Rate (TWR). Hasil dari eksperimen tersebut menghasilkan parameter optimum Aruslevel 2= 6 A; Ponlevel 1=100 µs dan Pofflevel 1=50µs.


2011 ◽  
Vol 264-265 ◽  
pp. 1450-1455 ◽  
Author(s):  
Gunawan Setia Prihandana ◽  
Tutik Sriani ◽  
Kei Prihandana ◽  
Yuta Prihandana ◽  
Muslim Mahardika ◽  
...  

The application of powder mixed dielectric to improve the efficiency of electrical discharge machining (EDM) has been acknowledged extensively. However, the study of micro-size powder suspension in micro-EDM field is still limited. In this research, nano and micro size powder of MoS2 were used as catalyst agent. Powder suspension in different size was able to provide significant improvement in material removal rate and surface quality to increase the efficiency in μ- EDM processes.


2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040145
Author(s):  
Quang Dung Le ◽  
Huu Phan Nguyen ◽  
Tien Long Banh ◽  
Duc Toan Nguyen

This study deals about the influence of vibrations incorporated into a workpiece during powder-mixed electrical discharge machining (PMEDM) on quality measures such as material removal rate (MRR), surface roughness [Formula: see text] and microhardness. It has been found that the low-frequency vibration incorporated into the workpiece positively affects the processing efficiency of electrical discharge machining (EDM) and PMEDM. However, the effect of low-frequency vibration in PMEDM has been better than EDM. The higher vibration frequency significantly improves the MRR and [Formula: see text] in PMEDM. The MRR has been improved by 95.89% and with lower [Formula: see text] of 63.2% in PMEDM. The hardness of the machined surface after PMEDM using titanium powder mixed in dielectric liquid was increased approximately two times as compared with conventional EDM.


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