scholarly journals ANALYSIS OF TOOL MATERIAL ON METAL REMOVAL RATE IN ELECTRICAL DISCHARGE MACHINING

2017 ◽  
Vol 20 (2) ◽  
pp. 21-24
Author(s):  
Himanshu Payal ◽  
2021 ◽  
Author(s):  
Dragan Rodic ◽  
Marin Gostimirovic ◽  
Milenko Sekulic ◽  
Borislav Savkovic ◽  
Branko Strbac

Abstract It is well known that electrical discharge machining can be used in the processing of nonconductive materials. In order to improve the efficiency of machining modern engineering materials, existing electrical discharge machines are constantly being researched and improved or developed. The current machining of non-conductive materials is limited due to the relatively low material removal rate and high surface roughness. A possible technological improvement of electrical discharge machining can be achieved by innovations of existing processes. In this paper, a new approach for machining zirconium oxide is presented. It combines electrical discharge machining with assisting electrode and powder-mixed dielectric. The assisting electrode is used to enable electrical discharge machining of nonconductive material, while the powder-mixed dielectric is used to increase the material removal rate, reduce surface roughness, and decrease relative tool wear. The response surface method was used to generate classical mathematical models, analyzing the output performances of surface roughness, material removal rate and relative tool wear. Verification of the obtained models was performed based on a set of new experimental data. By combining these latest techniques, positive effects on machining performances are obtained. It was found that the surface roughness was reduced by 18%, the metal removal rate was increased by about 12% and the relative tool wear was reduced by up to 6% compared to electrical discharge machining with supported electrode without powder.


Author(s):  
Ashwin Polishetty ◽  
Guy Littlefair

Titanium is known for its poor machinability characteristics due to its low thermal conductivity and high chemical reactivity. This article explores the machinability characteristics of selective laser melting (SLM) titanium alloy Ti-6Al-4V using wire cut electrical discharge machining (WEDM). For titanium alloys, exploring non-traditional machining operation such as WEDM is critical for a material failure or success in a design application. The research is to study the effect of parameters such as servo voltage, pulse on/off, and machining speed with respect to wire tension and wire feed rate on machinability. The outputs under consideration for evaluating machinability are metal removal rate (MRR) and surface finish under minimal interruption due to wire snaps. The article concludes by identifying the optimal factors responsible to produce an efficient and accurate cut with a minimum downtime.


2020 ◽  
Vol 38 (6A) ◽  
pp. 854-860
Author(s):  
Saad K. Shather ◽  
Sami A. Hammood ◽  
Noor Al-Huda A. Hussain ◽  
Noor H. Hasson

Increase the demand to produce complex shapes with high quality and dimensional accuracy such as production aerospace, cars, die sinking has been leading to increase the demand to use the non- traditional cutting operations such as wire electro-discharge machine (WEDM) rather than using the traditional operations. An idea to understand the effect of wire diameter, wire feed, pulsing (on/off) time on surface roughness, and metal removal rate of Cr-Mo steel during wire electrical discharge machining was investigated. Two Steel alloy samples with dimensions of (60 x50 x 20)mm were cut into four rectangular spaces with (5x10x20)mm at one side of each sample using wire cut (EDM) machine with a wire diameter of 0.25 mm and feeding rate 2 m/min for sample 1 and a 0.3 mm diameter and 3 m/min feeding rate for sample 2. Pulse (on, off) time was (110, 50), (112, 52), (115, 55), (116, 57) corresponds to space 1, space 2, space 3, and space 4 in both steel block. Surface roughness and metal removal rate measurements were estimated. The results showed that wire diameter, feeding rate, and pulse (on, off) time is proportional with metal removal rate, while reversed with surface roughness. The wire diameter of 0.3 mm and a feeding rate of 3m/min enhanced better surface quality and productivity. Pulse (on, off) time is the most effective parameter. Best duration time was recorded at the values (116, 57).


2019 ◽  
Vol 973 ◽  
pp. 157-160
Author(s):  
Stanislav A. Mozgov ◽  
Yuriy A. Morgunov ◽  
Boris P. Saushkin

This study investigates the possibility of electrochemical removal of the defective layer formed on the surface of the product after its electrical discharge machining. A set of experiments was conducted in different electrolytes based on aqueous and aqueous-organic solvents. The experiments were to trace the influence of such settings of electrochemical machining as current density, electrolyte pumping speed, electrolyte temperature, and an electrode gap upon both the dynamics of metal removal and surface quality. Morphology of the obtained surface was examined by an Olympus BX-51Microscope. The dynamics of removing material (stock) from the work piece was inspected. Appropriate adjustments were made to the machining parameters during the machining of 65G steels, and a preferred composition was selected for the working medium. A sufficient design for production tools was proposed. Pitting corrosion was discovered on the surface of the samples in all studied modes of electrolysis. It was observed that switching from aqueous electrolyte to aqueous-organic electrolyte gave lower material removal rate and longer machining time accordingly. At the same time, a reduction in surface roughness was visualized, together with smaller pits and lower density of their distribution. The obtained results may be applied in operation design for electrochemical machining of steels with relatively high carbon contents.


2009 ◽  
Vol 83-86 ◽  
pp. 756-763 ◽  
Author(s):  
P.S. Satsangi ◽  
K.D. Chattopadhyay

The use of thermo-electric source of energy, as in electrical discharge machining (EDM), has greatly helped in machining all types of electrically conductive materials being used in different industrial applications. The present work investigates the different machining characteristics during electrical discharge machining on EN-8 steel with a rotary copper electrode. The effects of three independent machining parameters viz. peak current, pulse on time and rotational speed of tool electrode are chosen as variables for evaluating the output parameters such as metal removal rate, surface finish of work piece. The research focuses on developing empirical models for prediction of metal removal rate and surface finish during rotary electrical discharge machining process with the help of input parameters. The models are developed using linear regression analysis by applying logarithmic data transformation of non-linear equation. Analysis of results using partial and multiple correlation analysis reveals that electrical parameters have more significant effect than the non-electrical parameters on the machining characteristics during electrical discharge machining by a rotary electrode. Furthermore, when high MRR is criterion, high peak current and low RPM with low pulse duration produces better output; whereas, and when smooth surface finish is criterion, low peak current and low RPM with high pulse duration produces better output. In addition, the predictions based on the above developed models are verified with extra experiments and are found to be in good agreement with the experimental verifications.


2012 ◽  
Vol 445 ◽  
pp. 994-999 ◽  
Author(s):  
Mohammad Reza Shabgard ◽  
Mirsadegh Seyedzavvar

This paper details the correlation between the input parameters with the tool material on the machining response in comparison of two different combinations of toolworkpiece material, namely copper-H13 and graphite-H13. The considered machining input parameters included pulse current and pulse on-time, and the investigated characteristics of the machining response were the material removal rate, tool wear, and surface roughness of the workpiece. Furthermore, differences in pulse shapes and process stability between the copper-H13 and graphite-H13 combinations were investigated.


Author(s):  
D Kondayya ◽  
A Gopala Krishna

This paper presents an application of an integrated evolutionary approach for modelling and optimization of a wire electrical discharge machining (WEDM) process. The proposed methodology consists of two parts. In the first part, a novel application of genetic programming (GP) is proposed. GP is an evolutionary modelling algorithm which uses principles similar to genetic algorithms to model highly non-linear and complex processes, resulting in accurate and reliable models. Two important aspects of machining performance of WEDM, namely metal removal rate and surface roughness, are modelled based on experimental data using GP in terms of four prominent input variables. The effect of machining parameters on the performance measures is also reported. In the second part, as the chosen machining performances are opposite in nature, the problem under consideration is formulated as a multi-objective optimization problem and solved using an efficient evolutionary optimization algorithm, non-dominated sorting genetic algorithm-II (NSGA-II). The outcome of Pareto optimal solutions is presented. The work presents a fully fledged evolutionary approach for optimization of the process.


2020 ◽  
Vol 38 (10A) ◽  
pp. 1504-1510
Author(s):  
Safaa K. Ghazi

The experimental work of this paper leads to electrical discharge machining (EDM). A system for machining in this process has been developed. Many parameters are studied such as current, pulse on-time, pulse off time of the machine. The main aim of this work is to calculate the metal removal rate (MRR) and electrode wear rate (EWR) using copper, electrodes when machining tool steel H13 specimens of a thickness (4mm). Different current rates are used ranging from (30, 42, and 54) Amp, pulse on-time ranging from (75, 100, and 125) and pulse off time ranging from (25, 50, and 75)   found that high current gives large electrode wear and metal removal rate and. The experiment design was by Taguchi Method. From an analysis of variance (ANOVA) the more active influence of input factors on the outputs is currently for metal removal rate (MRR) (58%) and electrode wear rate (EWR) (57).


Author(s):  
Fereydoon Rajabinasab ◽  
Vahid Abedini ◽  
Mohammadjafar Hadad ◽  
Ramezanali Hajighorbani

This research conducts in three sections. The first section studies the effect of tool materials and gases on rotary workpiece electrical discharge machining. During the experiments, the effects of three kinds of tool materials (Cu, Cu-Cr, and Cu-Sn) and three types of industrial gases (air, argon, and CO2) on the material removal rate, tool wear rate, and workpiece surface roughness are investigated. The second is a comparison between rotary workpiece, rotary tool, and the fixed workpiece by choosing the appropriate tool material and gas in order to observe the effect of workpieces rotation on the process. Finally, another comparison has been done between wet electrical discharge machining and near dry electrical discharge machining of the fixed workpiece in order to study the effect of the dielectric. The results show the copper tool has the best performance compared with other tools. Scanning electron microscopy output shows the Cu-Sn tool creates shallow micro-cracks on the surface. Air and CO2 gases have the higher material removal rate in low current, but argon has better function than other gases in high current. In addition, a rotational speed causes an increase in material removal rate and tool wear rate and surface roughness decrease in near dry electrical discharge machining. The level of tool wear rate has decreased by 14% in the rotary workpiece compared with the rotary tool.


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