EXPERIMENTAL INVESTIGATION OF MICRO-EDM OPERATION IN INCONEL 718

2021 ◽  
pp. 2150102
Author(s):  
MAYANK CHOUBEY ◽  
K. P. MAITY

The increasing trends towards miniaturized and lightweight components for various engineering and aerospace applications by unconventional machining the demand for micro-electrical discharge machining (EDM) have become increasingly wide. Micro-EDM is one of the most promising unconventional machining processes as compared to other unconventional machining due to its lower cost, ease of operation, and accuracy. This research explores the experimental investigation of micro-EDM operation on hard and difficult to machine material Inconel 718. The micro-holes were fabricated on an Inconel 718 workpiece with a copper electrode. The influence of input process parameters on material removal rate (MRR), machining time, and quality of the fabricated micro-holes were studied. Overcut and taperness of the fabricated micro-sized through holes were measured to address the accuracy of the fabricated micro-holes in micro-EDM operation. Experimental results reveal that the increase in current and voltage increases the MRR, and reduced machining time but at the cost of dimensional accuracy of the fabricated holes. The high value of current and voltage resulted in poor surface quality. The optimum machining condition that gives higher MRR with higher machining precision was obtained by experimenting while machining Inconel 718.

Author(s):  
Deepak Rajendra Unune ◽  
Amit Aherwar

Inconel 718 superalloy finds wide range of applications in various industries due to its superior mechanical properties including high strength, high hardness, resistance to corrosion, etc. Though poor machinability especially in micro-domain by conventional machining processes makes it one of the “difficult-to-cut” material. The micro-electrical discharge machining (µ-EDM) is appropriate process for machining any conductive material, although selection of machining parameters for higher machining rate and accuracy is difficult task. The present study attempts to optimize parameters in micro-electrical discharge drilling (µ-EDD) of Inconel 718. The material removal rate, electrode wear ratio, overcut, and taper angle have been selected as performance measures while gap voltage, capacitance, electrode rotational speed, and feed rate have been selected as process parameters. The optimum setting of process parameters has been obtained using Genetic Algorithm based multi-objective optimization and verified experimentally.


Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 594 ◽  
Author(s):  
Izidor Sabotin ◽  
Gianluca Tristo ◽  
Joško Valentinčič

In this paper, development of a technical model of micro Electrical Discharge Machining in milling configuration (EDM milling) is presented. The input to the model is a parametrically presented feature geometry and the output is a feature machining time. To model key factors influencing feature machining time, an experimental campaign by machining various microgrooves into corrosive resistant steel was executed. The following parameters were investigated: electrode dressing time, material removal rate, electrode wear, electrode wear control time and machining strategy. The technology data and knowledge base were constructed using data obtained experimentally. The model is applicable for groove-like features, commonly applied in bottom grooved micromixers (BGMs), with widths from 40 to 120 µm and depths up to 100 µm. The optimization of a BGM geometry is presented as a case study of the model usage. The mixing performances of various micromixer designs, compliant with micro EDM milling technology, were evaluated using computational fluid dynamics modelling. The results show that slanted groove micromixer is a favourable design to be implemented when micro EDM milling technology is applied. The presented technical model provides an efficient design optimization tool and, thus, aims to be used by a microfluidic design engineer.


2014 ◽  
Vol 984-985 ◽  
pp. 73-82 ◽  
Author(s):  
A. Kadirvel ◽  
P. Hariharan ◽  
M. Mudhukrishnan

Micro-EDM is an extensively used machining process for the fabrication of micro-holes with various advantages resulting from its characteristics of non-contact and thermal process. In this micro-fabrication technique, processing parameters greatly affect processing efficiency and stability. An experimental investigation on die-sinking Micro-EDM of EN-24 die steel using various electrodes such as tungsten, copper, copper tungsten and silver tungsten has been carried out. The present study aims to assess the quality and accuracy of the produced micro-holes, machining stability, material removal rate (MRR), tool wear ratio (TWR), surface roughness (Ra), Heat affected zone (HAZ) and overcut (OC). In addition, the influence of gap voltage, capacitance and discharge energy on the performance of the process has also been investigated. Experimental results proved that the overall performance of the copper electrode is found to be optimum with high MRR, thin HAZ though copper shows higher TWR, surface roughness and overcut.


Author(s):  
Deepak Rajendra Unune ◽  
Amit Aherwar

Inconel 718 superalloy finds wide range of applications in various industries due to its superior mechanical properties including high strength, high hardness, resistance to corrosion, etc. Though poor machinability especially in micro-domain by conventional machining processes makes it one of the “difficult-to-cut” material. The micro-electrical discharge machining (µ-EDM) is appropriate process for machining any conductive material, although selection of machining parameters for higher machining rate and accuracy is difficult task. The present study attempts to optimize parameters in micro-electrical discharge drilling (µ-EDD) of Inconel 718. The material removal rate, electrode wear ratio, overcut, and taper angle have been selected as performance measures while gap voltage, capacitance, electrode rotational speed, and feed rate have been selected as process parameters. The optimum setting of process parameters has been obtained using Genetic Algorithm based multi-objective optimization and verified experimentally.


2011 ◽  
Vol 264-265 ◽  
pp. 1056-1061 ◽  
Author(s):  
Muhammad Pervej Jahan ◽  
T. Saleh ◽  
Mustafizur Rahman ◽  
Yoke San Wong

Present study introduces low-frequency workpiece vibration during micro-EDM drilling of difficult-to-cut tungsten carbide with an objective to overcome the difficulty in flushing of debris and machining instability in deep-hole machining. The effects of vibration frequency, amplitude and electrical parameters on the machining performance, as well as surface quality and accuracy of the micro-holes have been investigated. It is found that the overall machining performance improves significantly with significant reduction of machining time, increase in material removal rate (MRR), and decrease in electrode wear ratio (EWR). The surface quality improves and the overcut and taper angle of the micro-holes reduces after applying the workpiece vibration in micro-EDM. The frequency and amplitude of 750 Hz and 1.5 μm were found to provide optimum performance.


2019 ◽  
Vol 26 (05) ◽  
pp. 1830008 ◽  
Author(s):  
K. P. MAITY ◽  
M. CHOUBEY

Electrical discharge machining (EDM) is an unconventional machining process used for machining of hard-to-cut materials. Both EDM and micro-EDM processes are extensively used for producing dies and molds, complex cavities, and 3D structures. In recent years, researchers have intensively focused on improving the performance of both micro-EDM and EDM processes. This paper reviews the research work carried out by the researchers on vibration-assisted EDM, micro-EDM, and wire EDM. The consolidated review of this research work enables better understanding of the vibration-assisted EDM process. This study also discusses the influence of vibration parameters such as vibration frequency and amplitude on the material removal rate (MRR), electrode wear rate (EWR), and surface roughness (SR). The important issues and research gaps in the respective area of research are also presented in this paper.


2011 ◽  
Vol 130-134 ◽  
pp. 927-930
Author(s):  
Jian Zhong Li ◽  
Fei Hu Shen ◽  
Mei Gang Guo

In conventional electrical discharge machining (EDM), the workpiece material is considered as homogenous material. When a micro feature is machined in alloy by micro EDM, microstructure of alloy may be of the same order as the micro feature. This may lead to the variation of machining performance of micro EDM. This paper demonstrates the influence of material microstructure on the machining performance by drilling micro holes within the crystal grain and on the boundary of TA0-1. Experimental results indicate that the average values of material removal rate, tool wear ratios and the discharge gaps on different locations are different because their material properties are different.


2016 ◽  
Vol 16 (1) ◽  
pp. 41-49
Author(s):  
V. Krishnaraj

AbstractTitanium alloys are categorized as light weight materials posse greater strength and toughness and are usually known to create major challenges during conventional and non-conventional machining. In general, these alloys are referred as difficult to machine materials. Titanium alloy (Ti-6Al-4V) suffers poor machinability for most cutting processes, especially the generation of micro-holes using traditional machining methods. Electrical Discharge Machining (EDM) is suitable for machining titanium alloys, although selection of machining parameters for higher machining rate and accuracy is a challenging task in machining micro-holes. Discharge current, pulse ON time and Flushing pressure were considered as the major influencing machining parameters and Material Removal Rate (MRR), Tool Wear Rate (TWR) and Hole Taper were considered as the performance criteria. It is observed that machining performances are affected mostly by the peak current and pulse-on time during micro-electro discharge machining of titanium alloy. Mathematical models have been developed using multiple regression analysis, to establish the relationship between various significant process parameters and micro-EDM performance criteria. Also, studies have been made to examine the influence of various process parameters on the quality of the machined micro-hole.


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.


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