Effects of hybrid Al2O3- SiO2 nanoparticles in deionized water on the removal rate and surface roughness during electrical discharge machining of Ti-6Al-4V

Author(s):  
Saeed Oskueyan ◽  
Vahid Abedini ◽  
Alireza Hajialimohamadi

Nowadays, special attention is paid to the application of nanoparticles to improve the performance of Electrical Discharge Machining (EDM). In this paper, modeling and optimizing the process parameters of Nanopowder Mixed Electrical Discharge Machining (NPMEDM) is studied. In this study, the effect of aluminum oxide (Al2O3) and silicon oxide (SiO2) nanoparticles on the deionized water dielectric is investigated simultaneously in the process of electrical discharge machining of Ti-6Al-4V alloy. After analyzing the parameters, the discharge current, concentration, pulse on time, and relative composition are considered as input factors. Response Surface Methodology (RSM) using Design-Expert software is employed for the design of the experiments, analysis of the results, and optimization of the parameters. The results show that the best surface morphology is obtained by machining with the addition of nanoparticles in the relative composition of 50%. In this percentage of the composition, the surface of the workpiece has the least value of crack and recast layer. In addition, the maximum value of the material removal rate (MRR) and minimum value of tool wear rate (TWR) can be achieved in the discharge current of 12 A, pulse on-time of 100 μs, and relative composition of 75% Al2O3 – 25% SiO2.

2020 ◽  
Vol 62 (5) ◽  
pp. 481-491
Author(s):  
Engin Nas

Abstract This study investigated the electrical discharge machining (EDM) performance of Ramor 500 Armor steel, a material used in the defense industry for armor production. In addition, the surface quality and amount of material wear of the treated surfaces were determined using different electrical discharge processing parameters for a copper electrode including pulse on-time (99, 150, 225, 300, 351 μs), pulse off-time (10, 15, 23, 30, 35 μs), and discharge current (3, 4, 6, 8, 9 A), at a constant pressure of 1 mm depth of cut. As a result of the experiments, the values related to the material removal rate (MRR) and the surface roughness (Ra) were obtained and the findings analyzed via response surface methodology (RSM). The increase in amperage and pulse on time resulted in an increase in Ra and MRR values. The minimum and maximum Ra and MRR values emerged at currents of 3 and 9 A, respectively. In the experiments performed applying currents of between 3 and 9 A, the white layer widths were measured as 0.0474 mm and 0.0915 mm, respectively. The statistical test results showed that the most effective processing parameters for the MRR were the discharge current amperage (49.01 %) and the pulse off-time (16.51 %), whereas the most effective parameter for the Ra value was the discharge current amperage (79.07 %).


Author(s):  
P Srinivasa Rao and Prof. Eshwara Prasad Koorapati

This work focuses on the use of the Taguchi method in order to find out the optimized parameters of the process like discharge current, pulse on time and pulse off time on the machining features such as material removal rate(MRR), surface roughness(SR) & tool wear rate(TWR) on Stavax Steel by means of Electrical Discharge Machining(EDM). It is also intended to study the individual influence of parameters on the performance characteristics. The dielectric fluid circulating system is modified to conduct the experiments. The analysis of variance (ANOVA) is made to recognise the importance of parameters on the response. By using non-linear regression analysis the empirical models are developed in order to predict these performance characteristics and the confirmation test was conducted at the optimal parameters settings to check the optimum expected values of performance features. Detailed analysis by using ANOVA is done and came out with the findings as a pulse on time is the most significant process parameter, next is the discharge current and the insignificant parameter is the pulse off time. Machining surface morphology was studied and observed that crater size is large and deeper due to a large amount of metal is melted and vaporized at the optimum condition of MRR.


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.


2020 ◽  
Vol 17 (5) ◽  
pp. 687-695
Author(s):  
Ruben Phipon ◽  
Ishwer Shivakoti ◽  
Ashis Sharma

Purpose This paper aims to present the performance of deionized water in electrical discharge machining (EDM) during machining of Inconel 718, copper tool electrode and deionized water as dielectric. Three parameters, namely, pulse-on-time, pulse-off-time and discharge current were taken as control parameters with individual parameter having three levels. Influence of these control parameters on response such as tool wear rate (TWR), material removal rate (MRR) and surface roughness (Ra) is evaluated at various combinations of parametric levels. The results reveal deionized water can be effectively used as a sustainable dielectric and may substitute the hydrocarbon-based dielectric in electrical discharge machining. Also, the control parameters considered show significant impact on the process criteria. Super ranking method was adopted to achieve optimal integration of EDM control factors for obtaining higher MRR, lower TWR and Ra. Further, by applying analysis of variance test, discharge current is established as the dominant parameter during the machining process. Design/methodology/approach The experimentation was performed on Inconel 718 in SPARKONIX MOS, 35 A, ZNC EDM using deionized water as dielectric and copper tool as electrode. The dielectric circulatory system was developed without disturbing the existing dielectric circulation system. Figure 1 shows the EDM with newly developed dielectric system. The existing system consists of hydrocarbon-based dielectric, which has a number of drawbacks during the machining such as carbide deposition on the work material, which reduces removal of material from work material; carbon particle adhesion on tool, which results in inefficient discharge between the electrode; and the work material and production of CO and CH4 during machining, which makes the machining environment toxic. To overcome these drawbacks, a sustainable dielectric was adopted in present work. Trial experiments were conducted to select the ranges of parameters, namely, discharge current, pulse-on-time and pulse-off-time. The process characteristics were evaluated at different parametric combinations and the experimentation was designed as per Taguchi L9 orthogonal array. Table 1 shows the properties of Inconel 718. Table 2 shows the parameters considered with its ranges. Table 3 shows the experimental values. The difference of weight of work piece before and after was taken and divided by the machining time used for calculating the MWR. Similarly, the difference of weight of tool material before and after was taken and divided by machining time and is used for calculating TWR. Measurement of surface roughness was done using Talysurf surface roughness meter. Findings The experimentation was conducted at different parametric combination on Inconel 718 taking copper as electrode and deionized water as dielectric. The performance criteria was evaluated at considered parametric combination. The result shows that the EDM parameters have significant contribution on the performance criteria and deionized water can be effectively used as dielectric medium in EDM. The use of deionized water as dielectric will improve the process and sustainable green machining can be performed. Super ranking method has been implemented to achieve the best combination of control factors and it is obtained that the combination A1B1C3 (i.e. discharge current = 3 A, pulse-on-time = 1 µs and pulse-off-time = 3 µs) is best combination for obtaining the higher MRR and lower TWR and Ra. The contributing factor in the proposed research work is discharge current. Further, ANOVA was implemented to check the adequacy of these result. It was established that discharge current is the most influential factor followed by pulse-on-time and the least contributing factor as pulse-off-time. The findings of this paper may open the guidelines for researcher for performing research in the field of sustainable machining of difficult to cut materials such as Inconel 718 with sustainable dielectrics in engineering applications. Originality/value The paper is original in nature. The findings of this paper may open the guidelines for researcher for performing research in the field of sustainable machining.


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.


2012 ◽  
Vol 488-489 ◽  
pp. 871-875
Author(s):  
V. Anandakrishnan ◽  
V. Senthilkumar

Copper based metal matrix composite reinforced with Boron Carbide is a newly developed Electrical Discharge Machining (EDM) electrode showing better performance than the conventional copper based electrode. Right selection of machining parameters such as current, pulse on time and pulse off time is one of the most important aspects in EDM. In this paper an attempt has been made to develop mathematical models for relating the Material Removal Rate (MRR), Tool Removal Rate (TRR) and Surface roughness (Ra) to machining parameters (current, pulse-on time and pulse-off time). Furthermore, a study was carried out to analyze thSubscript texte effects of machining parameters on various performance parameters such as, MRR, TRR and Ra. The results of Analysis of Variance (ANOVA) indicate that the proposed mathematical models, can adequately describe the performance within the limits of the factors being studied. Response surface modeling is used to develop surface and contour graphs to analyze the effects of EDM input parameters on outer parameters.


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.


2015 ◽  
Vol 656-657 ◽  
pp. 335-340 ◽  
Author(s):  
Fang Pin Chuang ◽  
Yan Cherng Lin ◽  
Hsin Min Lee ◽  
Han Ming Chow ◽  
A. Cheng Wang

The environment issue and green machining technique have been induced intensive attention in recent years. It is urgently need to develop a new kind dielectric to meet the requirements for industrial applications. The aim of this study is to develop a novel dielectric using gas media immersed in deionized water for electrical discharge machining (EDM). The developed machining medium for EDM can fulfill the environmentally friendly issue and satisfy the demand of high machining performance. The experiments were conducted by this developed medium to investigate the effects of machining parameters on machining characteristics in terms of material removal rate (MRR) and surface roughness. The developed EDM medium revealed the potential to obtain a stabilizing progress with excellent machining performance and environmentally friendly feature.


The growing demand for the use of high strength to weight alloys in industries for manufacturing complex structures challenges the machinability of such advanced materials. In the present investigation, the machinability of SiC particle reinforced Al 2124 composite was studied on Wire electrical discharge machining (WEDM). The process parameters namely pulse on-time (Ton), pulse off time (Toff), peak current (IP), and servo voltage (SV) were optimized by utilizing the central composite design layout. The output responses such as kerf and material removal rate (MRR) were studied in detail. The single and multi-objective optimization was studied for a combination effect using Derringer’s desirability approach and Genetic Algorithm (GA). The experimental and predicted values for each response were validated at the optimized condition. The experimental results were found in line with the predicted values. Multi objective optimization of kerf and MRR by GA showing better result compared to RSM.


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