scholarly journals Optimization of EDM Process Parameter for MRR and SR of 17- 4 PH Steel Using Response Surface Methodology

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
SHUBHRATA NAGPAL

In the present work, an attempt has been made for material removal rate and surface roughness by response surface optimization techniques in Electrical discharge machining. Electrical discharge machining, commonly known as EDM, is a process that is used to remove metal through the action of an electrical discharge of short duration and high current density between the work piece and too. This work presents the results of a mathematical investigation carried out to the effects of machining parameters such as current, pulse on time, pulse off time and lift time on material removal rate and surface roughness in electrical discharge machining of 17-4 PH steel by using copper electrode. Response surface methodology and ANOVA techniques are used for data analysis to solve the multi-response optimization. To validate the optimum levels of the parameter, confirmation run was performed by setting the parameters at optimum levels. Material Removal Rate during the process has been taken as productivity estimate with the objective to maximize it. With an intention of minimizing surface roughness is been considered as most important output parameter. It is found that the good agreement of that current is most significant parameter for material removal rate and less for surface roughness followed by pulse on time and lift time.

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Teepu Sultan ◽  
Anish Kumar ◽  
Rahul Dev Gupta

Electrical discharge machining is one of the earliest nontraditional machining, extensively used in industry for processing of parts having unusual profiles with reasonable precision. In the present work, an attempt has been made to model material removal rate, electrode wear rate, and surface roughness through response surface methodology in a die sinking EDM process. The optimization was performed in two steps using one factor at a time for preliminary evaluation and a Box-Behnken design involving three variables with three levels for determination of the critical experimental conditions. Pulse on time, pulse off time, and peak current were changed during the tests, while a copper electrode having tubular cross section was employed to machine through holes on EN 353 steel alloy workpiece. The results of analysis of variance indicated that the proposed mathematical models obtained can adequately describe the performances within the limits of factors being studied. The experimental and predicted values were in a good agreement. Surface topography is revealed with the help of scanning electron microscope micrographs.


Author(s):  
Rouhan Rafiq

Abstract: One of the important non-traditional machining processes is Wire Electrical Discharge Machining, used for machining difficult to machine materials like composites and inter-metallic materials. WEDM involves complex physical and chemical process including heating and cooling. Accompanying the development of mechanical industry, the demand for alloy materials having high hardness, toughness and impact resistance are increasing. The WEDM satisfy the present demands of the manufacturing industries such as better finish, low tolerance, higher production rate, miniaturization etc. The consistent quality of parts being machined in WEDM is difficult because the process parameters cannot be controlled effectively. The problem of arriving at the optimum levels of the operating parameters has attracted the attention of the researcher and practicing engineers for a very long time. The objective of the present study was to experimentally investigate the effects of various Wire Electrical Discharge Machining variables on Surface Roughness and Material Removal Rate of AISI 1045 using ANOVA method. Taguchi’s L18 Orthogonal Array was used to conduct experiments, which correspond to randomly chosen different combination of process parameters: wire type, pulse on time, pulse off time, peak current, servo voltage, wire feed rate, flushing pressure each to be varied in three different levels. The surface roughness and material removal rate were selected as output responses for the present investigation. The effect of all the input parameters on the output responses have been analyzed using analysis of variance (ANOVA). The effect of variation in input parameters has been studied on the output responses. Plots of S/N ratio have been used to determine the best relationship between the responses and the input parameters. In other words, the optimum set of input parameters for minimum surface roughness and maximum material removal rate were determined. It has been found that wire type, pulse on time are most significant factors for surface roughness and wire type, pulse on time, pulse off time, wire feed rate are most significant factors for material removal rate. Keywords: Input Parameters, Wire Electric Discharge Machining, ANOVA, Taguchi


2021 ◽  
Author(s):  
Muhammad Qaiser Saleem ◽  
Maham Naqvi ◽  
Sarmad Ali Khan ◽  
Nadeem Ahmad Mufti ◽  
Kashif Ishfaq

Abstract Review of the available literature on powder mixed electrical discharge machining (PMEDM) indicates, that most of the research has been done for “die sinking machining mode” whereas the “wire cut machining mode” has not received due attention despite being an important process variant. This work employs Silicon Carbide (SiC) powder mixed dielectric fluid for machining of AISI D2 in “wire cut” mode with re-circulating molybdenum wire (an economic and chemically stable proposition as tool). The effect of five process parameters (powder concentration, peak current, pulse on time, nozzle flushing pressure and stand-off distance) have been evaluated on surface roughness, kerf width, material removal rate and wire wear ratio using Taguchi’s approach. It is found that for surface roughness, higher current and low to moderate concentration levels (2 to 4g/l) deteriorate surface quality; higher values of pressure and stand-off distance are also seen to adversely affect it. For material removal rate, pulse on time as well as its interactions with powder concentration and current, are statistically significant. A higher pulse on with smaller and moderate powder concentrations (2g/l and 4g/l) reduces MRR. For wire wear ratio, current is the sole significant factor (PCR of ~ 65%). SEM analysis of the machined workpiece for the maximum MRR condition quantifies recast layer as ~ 19microns. An indirect comparison with the reported values for non-powdered EDM process indicates that for the similar wire (molybdenum), the use of SiC powder maintains the surface roughness and kerf values, for a much harder D2 material used in this work.


2021 ◽  
Vol 23 (12) ◽  
pp. 224-235
Author(s):  
N. Ethiraj ◽  
◽  
T. Sivabalan ◽  
Saibal Chatterjee ◽  
Seeramsetti Mahesh ◽  
...  

One of the non-conventional techniques of metal removal manufacturing processes is electrical discharge machining (EDM). The objective of this paper is to prepare a composite material consisting of a matrix of Aluminium AA 6061 alloy and Boron carbide (B4C) as reinforcement and investigate the output responses, the material removal rate, the quality of the surface formed and overcut during EDM process. The process parameters discharge current, Pulse on time and Duty cycle along with the weight % of B4C are considered for investigation to investigate the output responses such as material removal rate, surface roughness and overcut. From the experimental results, it is observed that the weight % of reinforcement has more influence on the material removal rate. The parameters discharge current and pulse-on-time plays an important role in reducing the surface roughness and overcut. Microstructural study helps in understanding the effect of process parameters on the output responses.


Author(s):  
G. Ramanan ◽  
R. Elangovan

In aerospace and automobile industries manufacturing complex structures using un-conventional machining is increased due to their precision and accuracy. This research investigates the influence of input parameters such as discharge current, pulse on time, pulse off time and servo speed rate of wire cut electrical discharge machining (WEDM) on material removal rate and surface roughness using Box Behnken design supported with response surface methodology. Aluminium alloy 7075 reinforced with 9 % wt. of activated carbon composite is used to carry out the machining process. Most influencing parameters are subjected as the conductive and non-conductive parameters in WEDM process. To find out the significant influence of each factor, analysis of variance was performed. The mathematical model is established using desirability technique and then the optimal machining parameters are determined. The best achieved WEDM performances - material removal rate and surface roughness are 10.46 mm3/min and 3.32μm respectively, by using optimum machining conditions - discharge current 2000mA, pulse on time 8.9µs, pulse off time 25µs and servo speed rate 150rpm at 0.8597 desirability value.


2020 ◽  
Vol 10 (1) ◽  
pp. 401-407
Author(s):  
Yanuar Rohmat Aji Pradana ◽  
Aldi Ferara ◽  
Aminnudin Aminnudin ◽  
Wahono Wahono ◽  
Jason Shian-Ching Jang

AbstractThe machinability information of Zr-based bulk metallic glasses (BMGs) are recently limited but essential to provide technological recommendation for the fabrication of the medical devices due to the material’s metastable nature. This study aims to investigate the material removal rate (MRR) and surface roughness under different current and pulse-on time of newly developed Ni- and Cu-free Zr-based BMG using sinking-electrical discharge machining (EDM). By using weightloss calculation, surface roughness test and scanning electron microscopy (SEM) observation on the workpiece after machining, both MRR and surface roughness were obtained to be increased up to 0.594 mm3/min and 5.50 μm, respectively, when the higher current was applied. On the other hand, the longer pulse-on time shifted the Ra into the higher value but lower the MRR value to only 0.183 mm3/min at 150 μs. Contrary, the surface hardness value was enhanced by both higher current and pulse-on time applied during machining indicating different level of structural change after high-temperature spark exposure on the BMG surface. These phenomena are strongly related to the surface evaporation which characterize the formation of crater and recast layer in various thicknesses and morphologies as well as the crystallization under the different discharge energy and exposure time.


Author(s):  
TS Senthilkumar ◽  
R Muralikannan ◽  
T Ramkumar ◽  
S Senthil Kumar

A substantially developed machining process, namely wire electrical discharge machining (WEDM), is used to machine complex shapes with high accuracy. This existent work investigates the optimization of the process parameters of wire electrical discharge machining, such as pulse on time ( Ton), peak current ( I), and gap voltage ( V), to analyze the output performance, such as kerf width and surface roughness, of AA 4032–TiC metal matrix composite using response surface methodology. The metal matrix composite was developed by handling the stir casting system. Response surface methodology is implemented through the Box–Behnken design to reduce experiments and design a mathematical model for the responses. The Box–Behnken design was conducted at a confident level of 99.5%, and a mathematical model was established for the responses, especially kerf width and surface roughness. Analysis of variance table was demarcated to check the cogency of the established model and determine the significant process. Surface roughness attains a maximum value at a high peak current value because high thermal energy was released, leading to poor surface finish. A validation test was directed between the predicted value and the actual value; however, the deviation is insignificant. Moreover, a confirmation test was handled for predicted and experimental values, and a minimal error was 2.3% and 2.12% for kerf width and surface roughness, respectively. Furthermore, the size of the crater, globules, microvoids, and microcracks were increased by amplifying the pulse on time.


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.


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