Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : MRR


Investigation the Effect of Negative Polarity of Surface Roughness and Metal Removal Rate During EDM Process

Shahd A. Taqi; Saad K. Shather

Engineering and Technology Journal, 2020, Volume 38, Issue 12, Pages 1852-1861
DOI: 10.30684/etj.v38i12A.1591

The Electro discharge machine that named (EDM) is used to remove the metal from the workpiece by spark erosion. The work of this machining depends on the multiple variables. One of the most influential variants of this machine is the polarity, the material of the electrode, the current and the time pulses. Essentially the polarity of the tool (electrode) positive and the work piece is negative, this polarity can be reversed in this paper was reversed the polarity that was made the tool (electrode) negative and the work piece was positive. The aim of this paper was focused on the influence of reversed the polarity (negative) with changing the electrode metal (copper and graphite) on the surface roughness and metal removal rate by using different parameters (current and pulses of time). Experiments show that: the copper electrode gives (best surface roughness 0.46 μm when the current 5 Am and Ton 5.5 μs) and (worst surface roughness 1.66 μm when the current is 8 A and Ton 25 μs). And give (best values of the MRR 0.00291 g/min when the current is 8 and Ton 25 μs) and (The lowest values of MRR (0.00054 g/min when current is 5 and Ton 5.5 μs). The graphite electrode gives (best surface roughness 2.07 μm when the current 5 Am and Ton 5.5 μs) and (worst surface roughness 4.17 μm when the current is 8 A and Ton 25 μs). And give (best values of the MRR 0.05823 g/min when the current is 8 and Ton 25 μs) and (The lowest values of MRR (0.00394 g/min when current is 5 and Ton 5.5 μs).

Effect of SiC-Cu Electrode on Material Removal Rate, Tool Wear and Surface Roughness in EDM Process

Yousif Q. Laibi; Saad K. Shather

Engineering and Technology Journal, 2020, Volume 38, Issue 9, Pages 1406-1413
DOI: 10.30684/etj.v38i9A.552

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.

Influence of Polarity of Electro Discharge Machine (EDM) on Surface Roughness (SR) and Metal Removal Rate (MRR) of Low Carbon Steel

Shahd Taqi; Saad K. Shather

Engineering and Technology Journal, 2020, Volume 38, Issue 7, Pages 975-983
DOI: 10.30684/etj.v38i7A.469

Electro discharge machining (EDM) is one of a thermal process that is used for remove of metal from the workpiece by spark erosion. The work of this machine depends on multiple variables. One of the more influential variants on this machine is the change of polarity and the use of this variable is not wide and the research depends on the polarity of the machinist. Essentially, the polarity of the tool (electrode) is positive and the workpiece is negative, this polarity can be reversed. This paper focuses on the influence of changing the polarity (positive and negative) on the surface roughness and metal removal rate by using different parameters (current, voltages, polarity and Ton). Experiments show that the positive electrode gives (best surface roughness = 1.56 μm when the current = 5 Am and Ton = 5.5 μs) and (best metal removal rate = 0.0180 g/min when the current = 8 Am and Ton = 25 μs). Negative electrode gives (best surface roughness = 0.46 μm when the current = 5 Am and Ton = 5.5 μs) and (best metal removal rate = 0.00291 g/min when the current = 8 Am and Ton = 25 μs).

Experimental Investigation on Electrochemical Grinding (ECG) for Stainless Steel 316

Abdullah J. Ghadban; Abbas F. Ibrahim

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 20-25
DOI: 10.30684/etj.v38i1A.176

This research focuses on material removal rate (MRR) and surface roughness during electrochemical grinding (ECG) for stainless steel 316. The effect of applied current, electrolyte concentration, gap size and spindle speed on machining performances has been studied. Where applied current used are (10, 20, 30, 40) A, electrolyte concentration used (100, 150, 200, 250) g/l, gap size used (0.2, 0.3, 0.4, 0.5) mm and spindle speed used (75, 150, 180, 280) rpm. Through the Taguchi design based experimental study the characteristic features of the ECG process are discussed. Where the maximum MRR can be obtained at 40 A of the current, 250 g/l of the concentration, 0.2 mm of the gap and 180 rpm of spindle speed. The best surface roughness can be obtained at 10 A of the current, 200 g/l of the concentration, 0.4 mm of the gap and 280 rpm of spindle speed..

Prediction of Surface Roughness and Material Removal Rate for 7024 AL-Alloy in EDM Process

Abbas Fadhil Ibrahim; Mostafa Adel Abdullah; Safaa Kadhim Ghazi

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2796-2804

This paper studies prediction the values of MRR and surface roughness in Electrical discharge operations. It is a operation in which the material removal rate is machined with elevation spark in the midst work piece and electrode sunken through dielectric solution.Through use Taguchi found that the accuracy of the measured and prediction values that have been is 93% and 99% for each of the MRR and surface roughness respectively. The effect of different Electrical discharge machining factors are (Gap, pulse off time and pulse on time) to predict the (material removal rate) and (roughness). Note that connected pole that was used is copper. From (ANOVA) found that the large parameter effect on MRR is pulse-on 65% and pulse-off 25% while large parameter effect for surface roughness is pulse-on 96% . The least influential parameter for metal removal rate is the gap and the least influential parameter for surface roughness is pulse-off and Gap.

Investigation of Material Removal Rate and Surface Roughness for AISI 1015 Steel Rack Gear in Wire EDM Process

Mostafa Adel Abdullah; Safaa Kadhim Ghazi; Mustafa Mohamed

Engineering and Technology Journal, 2016, Volume 34, Issue 12, Pages 2361-2370

In this work an investigation of the effects of various process parameters of Wire-EDM like Servo Feed (SF), pulse off-time (TOFF), pulse on-time (TON), as inputs impact on surface roughness (Ra) and metal removal rate (MRR) as outputs on steel (AISI 1015) utilizing nine specimens. With servo feed (500, 600 and 700)mm/min, pulse-of time (10,30,50) μsec, pulse on-time (20,25,30) μsec.The characteristics of cutting variables were determined by implementing Taguchi experimental design method. The importance level of the cutting variables for metal removal rate and surface roughnessis determined by implementing the analysis of variance (ANOVA).

Effect of Powder Concentration in PMEDM on Machining Performance for Different Die steel Types

Maan Aabid Tawfiq; Azzam Sabah Hameed

Engineering and Technology Journal, 2015, Volume 33, Issue 9, Pages 2174-2186

Electric discharge machining(EDM) is one of the nonconventional machining process which has been used in manufacturing complex shapes on hard material that are difficult to cut by conventional processes, especially, die casting, parts of aircraft, medical equipment, automobile industries. Powder mixed electric discharge machining(PMEDM), has emerged as one of the advanced techniques in the direction of the enhancement of the capabilities of EDM. The objective of the present research is to study the influence of process parameters such as peak current, pulse on time, manganese,aluminum, and aluminum-manganese mixing powder concentration on machining performance of different types of die steel (AISID3,AISID6,H13)with round copper electrode(20 mm diameter) on machining performance. Experiments have been designed using Taguchi method. Taguchi L27 orthogonal array has been selected for five factors 3 levels design. The machining performance has evaluated in terms of metal removal rate (MRR).It is found that manganese powder concentration mixed in dielectric fluid significantly affect the machining performance, maximum (MRR) is obtained at a high peak current(12 A), pulse on(200µs), and (4g/L) concentration of manganese powder,the optimum MRR is 17.56mm3/min with percent of error about 5.61% compared with the Experimental value.

Study the Effect of Electrical Current on Average Surface Roughness of Borosilicate Glass at EDM Machining and Comparison Using Matlab Program

Shukry H. Aghdeab; Ahmed A. Abulwahhab

Engineering and Technology Journal, 2011, Volume 29, Issue 6, Pages 1157-1165

Machining of electrically non-conducting materials like glass is still a major
problem. The principle of electric arc was used to generate high electrical
discharge (spark) at high currents to machine non-conducting materials at any
hardness.
EDM system was build for machining of non-conducting cutting materials
such as glass including the use of powder (graphite) mixed for dielectric solution
(tap water) by supplied DC current values (200, 250, 300, 350 and 400A). Voltage
of (70V) was used to cut 3mm thickness of borosilicate glass (BSG) to obtain the
average surface roughness (Ra) of about (0.003-0.012μm).
Matlab program has been used to investigate the process control for EDM that
could the Ra experimental and theoretical with accuracies of 94.236, 94.034,
96.628 and 92.875% respectively.
From the reading of the magnitude of the roughness it was found that differences
between the theoretical and experimental values for 3mm thickness of BSG was
never exceed (8%).

Effect of Current on Average Surface Roughness of Borosilicate Glass at EDM Machining and Comparison with Numerical Programs

Wathik I. Mahdi; Maan A. Tawfiq; Shukry H. Aghdeab

Engineering and Technology Journal, 2009, Volume 27, Issue 6, Pages 1026-1038

Machining of electrically non-conducting materials like glass is still a major problem. The principle of electric arc was used to generate high electrical discharge (spark) at high currents to machine non-conducting materials at any hardness, which is a new approach.
EDM system was build for machining of non-conducting cutting materials such as glass with new technology including the use of powder (graphite) mixed for dielectric solution (tap water) by supplied AC current values (200, 250, 300, 350 and 400A). Voltage of (70V) was used to cut 3mm thickness of borosilicate glass (BSG) to obtain the average surface roughness (Ra) of about (0.003-0.012μm) but the Ra before the machining was (0.005-0.006μm).
Numerical program called "Simulent" has been used to investigate the process control for EDM by using GN, BPN, PN and VQN that could predict the Ra with accuracies of 94.236, 94.034, 96.628 and 92.875% respectively from training data sets.
The differences on the Ra at different network models for 3mm thickness of BSG never exceed (8%) from testing data sets while the comparison of numerical results with experimental results of Ra among the measured values and prediction various network models, shows a differences between (1-8%).
The best predication accuracy is by the use of PN than other network models.