A Case Study on Quality and Productivity Optimization in Electric Discharge Machining (EDM)

2012 ◽  
Vol 445 ◽  
pp. 27-32 ◽  
Author(s):  
H. Dalai ◽  
S. Dewangan ◽  
Saurav Datta ◽  
S.K. Patel ◽  
S.S. Mahapatra
Keyword(s):  
Optimal Parameter ◽  
Removal Rate ◽  
Desirability Function ◽  
Global Market ◽  
Advanced Technology ◽  
Electric Discharge Machining ◽  
Machined Surface ◽  
Precise Control ◽  
Productivity Estimate

Quality and productivity are two important aspects have become great concerns in todays competitive global market. Every manufacturing/ production unit mainly focuses on these areas in relation to the process as well as product developed. Achieving high quality necessarily requires higher degree of skill, sophisticated machine/ tools, advanced technology, precise control, immense attention-inspection and considerable time. Improvement of quality results reduction in productivity and vice versa. Thus, optimality must be maintained between quality as well as productivity. The case study highlights EDM of stainless steel in which best process environment (optimal) has been determined to satisfy productivity and quality requirements simultaneously. Material Removal Rate (MRR) during the process has been considered as productivity estimate with the aim to maximize it; whereas surface roughness i.e. (Ra value) of the machined surface has been chosen as surface quality estimate with the requirement to minimize it. These two contradicting requirements have been simultaneously satisfied by selecting an optimal process environment (optimal parameter setting). Desirability Function (DF) approach coupled with Taguchi method has been used to solve the problem.

A Brief Review of Experimental Investigations and Analytical Development of Powder Mixed Electric Discharge Machining (PMEDM)

2021 ◽  
Vol 106 ◽  
pp. 31-38
Author(s):  
Sovan Bhowmick ◽  
Gautam Majumdar ◽  
Asish Bandyopadhyay
Keyword(s):  
Electric Discharge ◽  
Material Removal ◽  
Removal Rate ◽  
White Layer ◽  
Thermal Characteristics ◽  
Tool Wear Rate ◽  
Electric Discharge Machining ◽  
Machined Surface ◽  
Electrically Conductive ◽  
White Layer Thickness

Powder mixed electric discharge machining (PMEDM) is a newly developed technology in which EDM is performed by mixing electrically conductive micro or nanoparticles with dielectric fluid. The electrically conductive tiny particles when come at the gap of electrode and work piece, they will begin to create spark by the induction of electrode voltage which enhances the material removal and surface finish of the machined surface. In this paper a brief review has been done on different aspects of powder mixed electric discharge machining. It is observed that the researches are done in three main directions. Firstly, experimental studies are done to show the effect of several input process parameters on responses mainly material removal rate (MRR), surface roughness and tool wear rate. Secondly, the metallurgical characteristics of the machined surface are analyzed to measure the white layer thickness and amount of powder material inclusion onto the surface. The third one is the investigation of thermal characteristics of the tool and work pieces during the machining process. In these three sections of researches, the results of the investigations have been discussed in this review. Keywords: powder mixed electric discharge machining, metallurgical characteristics, nano particles, material removal rate, surface roughness, tool wear rate, white layer thickness, thermal characteristics

Ultrasonic Machining: A Review

2016 ◽  
Vol 1137 ◽  
pp. 61-78 ◽  
Author(s):  
Ravinder Kataria ◽  
Jatinder Kumar
Keyword(s):  
Surface Defects ◽  
Hybrid Methods ◽  
Removal Rate ◽  
Fundamental Principle ◽  
Ultrasonic Machining ◽  
Machining Processes ◽  
Electric Discharge Machining ◽  
Machined Surface ◽  
Laser Beam Machining ◽  
Manufacturing Method

Ultrasonic machining is a contemporary manufacturing method usually employed for processing materials with higher hardness/brittleness such as quartz, semiconductor materials, ceramics etc. The machined surface produced by ultrasonic machining is found to be free from any surface defects (heat affected zone, cracks, recast layer, etc.) in contrast to the thermal based machining processes like; electric discharge machining, laser beam machining etc. In this article, a review has been reported on the fundamental principle of ultrasonic machining, effect of operating parameters on material removal rate, tool wear rate, surface roughness and hole quality. It also presents a brief review on micro-USM, rotary USM and hybrid methods with other processes.

scholarly journals Optimisation of Current and Pulse Duration in Electric Discharge Drilling of D2 Steel Using Graphite Electrode

2018 ◽  
Vol 15 (4) ◽  
pp. 5914-5926
Author(s):  
D. Deepak ◽  
Patil Shrinivas ◽  
Ganti Hemant ◽  
Ralisa Iasy
Keyword(s):  
Electric Discharge ◽  
Material Removal ◽  
Morphological Analysis ◽  
Graphite Electrode ◽  
Removal Rate ◽  
Electric Discharge Machining ◽  
Machined Surface ◽  
Spark Erosion ◽  
D2 Steel ◽  
Selection Of

Electric discharge machining (EDM) is one of the viable techniques for machining of D2 steel, in which the material removal occurs by spark erosion. The poor selection of EDM parameters affect the machining quality and productivity. Considering this, the present work investigates the effect of current, charging and discharging time on the material removal rate (MRR) and the surface roughness (Ra) while machining of D2 steel using graphite electrode. The results were analysed using statistical methods to identify the effect of control parameters and to optimise the settings. The study shows that MRR and Ra was significantly influenced by current. At optimum settings, the MRR and the Ra obtained was 38.16 mg/min and 3.39 µm respectively. Morphological analysis of the machined surface show that the size of the globules formed decreased with increase in current.

scholarly journals Modeling of Interelectrode Gap in Electric Discharge Machining and Minimum Variance Self-Tuning Control of Interelectrode Gap

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Bin Xin ◽  
Ming Gao ◽  
Shujuan Li ◽  
Bin Feng
Keyword(s):  
Electric Discharge ◽  
Removal Rate ◽  
Short Circuit ◽  
Minimum Variance ◽  
Machining Process ◽  
Electric Discharge Machining ◽  
Precise Control ◽  
Interelectrode Gap ◽  
Machining System ◽  
P Type

In the electric discharge machining system, the determination of the gap between the anode and the cathode is a difficult point of this kind of machining approach. An accurate mathematical model of interelectrode gap is obtained, and the precise control of the gap is achieved on this basis. In this paper, based on the example of discharge machining of P-type single crystal Si, the theoretical analysis proved that the discharge channel can be equivalent to pure resistance, and the physical model of the interelectrode gap and voltage and current was established. The order and parameters of the EDM system model were determined by adopting the system identification theory. We designed the minimum variance self-correcting controller to accurately control the interelectrode gap in combination with the actual machining process. Experimental results show that the interelectrode gap model can correctly reflect the interelectrode gap in the actual machining process; the minimum variance self-correcting controller eliminates the short circuit phenomenon during processing and can stably track different desired gaps; the material removal rate and the surface roughness decrease with the increase of the interelectrode gap.

Machining performance of cryogenically treated Ti–5Al–2.5Sn titanium alloy in electric discharge machining: A comparative study

2016 ◽  
Vol 231 (11) ◽  
pp. 2017-2024 ◽  
Author(s):  
Sanjeev Kumar ◽  
Ajay Batish ◽  
Rupinder Singh ◽  
TP Singh
Keyword(s):  
Titanium Alloy ◽  
Material Removal Rate ◽  
Electric Discharge ◽  
Material Removal ◽  
Removal Rate ◽  
Cryogenic Treatment ◽  
Machining Performance ◽  
Electric Discharge Machining ◽  
Machined Surface ◽  
Pulse On Time

In the present study, the effect of cryogenic treatment on the machining performance of Ti–5Al–2.5Sn alpha titanium alloy was investigated during electric discharge machining. Untreated, shallow cryogenically treated (−110 ℃), and deep cryogenically treated (−184 ℃) titanium alloys were machined by varying current and pulse-on-time. The machining performance was measured in terms of higher material removal rate and microhardness and low tool wear rate and surface roughness. The results showed a significant improvement in the machining performance with deep cryogenically treated alloy when compared with shallow and untreated alloy. Current and pulse-on-time also affected the machinability of titanium alloy. Higher material removal rate and microhardness were observed when titanium alloy was machined at high current and pulse-on-time. During machining, carbon was deposited on the machined surface due to the breakdown of hydrocarbon dielectric at high temperature thereby, affecting its properties.

Root Cause Analysis for Pin Leakage

2016 ◽  
Author(s):  
Zhigang Song ◽  
Jochonia Nxumalo ◽  
Manuel Villalobos ◽  
Sweta Pendyala
Keyword(s):  
Failure Analysis ◽  
Root Cause Analysis ◽  
Advanced Technology ◽  
Process Step ◽  
Cause Analysis ◽  
Hard Mask ◽  
Technology Node ◽  
Root Cause ◽  
Tools And Techniques

Abstract Pin leakage continues to be on the list of top yield detractors for microelectronics devices. It is simply manifested as elevated current with one pin or several pins during pin continuity test. Although many techniques are capable to globally localize the fault of pin leakage, root cause analysis and identification for it are still very challenging with today’s advanced failure analysis tools and techniques. It is because pin leakage can be caused by any type of defect, at any layer in the device and at any process step. This paper presents a case study to demonstrate how to combine multiple techniques to accurately identify the root cause of a pin leakage issue for a device manufactured using advanced technology node. The root cause was identified as under-etch issue during P+ implantation hard mask opening for ESD protection diode, causing P+ implantation missing, which was responsible for the nearly ohmic type pin leakage.

EDM with USM Combination Process of Sintered NdFeB Permanent Magnet

2010 ◽  
Vol 44-47 ◽  
pp. 1066-1069
Author(s):  
Li Li ◽  
Li Ling Qi ◽  
Zong Wei Niu
Keyword(s):  
Permanent Magnet ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Characteristics ◽  
Dielectric Fluid ◽  
Machined Surface ◽  
Combination Process ◽  
Electro Discharge Machining ◽  
Ndfeb Permanent Magnet ◽  
Machining Characteristics

This paper presents an experimental investigation of the machining characteristics of sintered NdFeB permanent magnet using a combination process of electro-discharge machining (EDM) with ultrasonic machining (USM). Concentration of abrasive in the dielectric fluid is changed to explore its effect on the material removal rate (MRR). MRR of EDM /USM, conventional EDM are compared, machined surface characteristics are also compared between them. It is concluded that the combination EDM/USM process can increase the MRR and decrease the thickness of the recast layer. In the combination process, an appropriate abrasive concentration can improve its machining efficiency.

Microbial contamination in groundwater supply in a cold climate and coarse soil: case study of norovirus outbreak at Lake Mývatn, Iceland

2013 ◽  
Vol 44 (6) ◽  
pp. 1114-1128 ◽  
Author(s):  
M. J. Gunnarsdottir ◽  
S. M. Gardarsson ◽  
H. O. Andradottir
Keyword(s):  
Rural Areas ◽  
Microbial Contamination ◽  
Removal Rate ◽  
Late Summer ◽  
Cold Climate ◽  
Systematic Evaluation ◽  
Septic Systems ◽  
Groundwater Velocity ◽  
Groundwater Supply

This paper explores the fate and transport of microbial contamination in a cold climate and coarse aquifers. A confirmed norovirus outbreak in a small rural water supply in the late summer of 2004, which is estimated to have infected over 100 people, is used as a case study. A septic system, 80 m upstream of the water intake, is considered to have contaminated drinking water. Water samples tested were negative for coliform and strongly positive for norovirus. Modelling predicts that a 4.8-log10 removal was possible in the 8 m thick vadose zone, while only a 0.7-log10 and 2.7-log10 removal in the aquifer for viruses and Escherichia coli, respectively. The model results support that the 80 m setback distance was inadequate and roughly 900 m aquifer transport distance was needed to achieve 9-log10 viral removal. Sensitivity analysis showed that the most influential parameters on model transport removal rate are grain size diameter and groundwater velocity, temperature and acidity. The results demonstrate a need for systematic evaluation of septic systems in rural areas in lesser studied coarse strata at low temperatures, thereby strengthening data used for regulatory requirements for more confident determination on safe setback distances.

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