Optimizing the powder mixed EDM process of nickel based super alloy

Author(s):  
S Ramesh ◽  
MP Jenarthanan

Powder Mixed Electric Discharge Machining has been the main focus of many researchers for quite a long time. The performance of EDM process has been improved significantly by using powder mixed dielectric medium. Numerous researches were undertaken to study the influence of different process parameters involved in the powder mixed EDM by experimenting with different work materials and powder combination. The objective of this work is to conduct experimental study on the powder Mixed EDM of a Nickel based super alloy, Nimonic 75, using three different powders which are graphite, silicon and manganese. The other important process parameters considered are concentration of powder (Cp), peak current (Ip), duty factor (DC). The experiments were conducted based on the Response Surface Methodology (RSM) design. The important measures of performance of EDM process chosen in this study are Material Removal Rate (MRR), Electrode Wear ratio (EWR) and Surface Roughness (SR). Graphite powder yielded highest MRR and silicon powder produced good finish of the components. The influence of powder at higher concentration is not significantly high. Moreover, Higher duty cycle caused the decrease of MRR, EWR and increase of SR. This works also aims to optimize the process parameters using Grey Relational Analysis (GRA) combined with Fuzzy logic method. The optimum conditions identified based on GFRG was powder = Mn; concentration = 3 g/l; discharge current = 4 A and duty cycle = 0.9 It was also estimated that the error in predicting best output of the PMEDM process is below 6%.

Author(s):  
Shivraj Yeole ◽  
Nagabhushana Ramesh Nunna ◽  
Balu Naik Banoth

Electrical Discharge Micro Drilling (EDMD) is considered as one of the most effective method for machining difficult to cut and hard materials like titanium alloy. However, selection of process parameters for achieving superior surface finish, higher machining rate and accuracy is a challenging task in drilling micro-holes. In this paper, an attempt is made to optimize micro-EDM process parameters for drilling micro holes on titanium grade 19 alloy. In order to verify the optimal micro-EDM process parameters settings, material removal rate (MRR), electrode wear rate (EWR) and over cut (OC) were chosen as the responses to be observed. Pulse on time, pulse off time, electrode diameter and current were selected as the governing process parameters for evaluation by Taguchi method. Nine micro holes of 300 μm, 400 μm and 500 μm were drilled using L9 orthogonal array (OA) design. Optimal combination of machining parameters were obtained through Signal-to-Noise (S/N) ratio analysis. It is seen that machining performances like material removal rate and overcut are affected by the peak current whereas electrode wear is affected by peak current and electrode diameter. Morphology of the micro holes has been studied through SEM micrographs of machined micro-hole.


2015 ◽  
Vol 766-767 ◽  
pp. 674-680
Author(s):  
P. Karunakaran ◽  
J. Arun ◽  
V. Palanisamy ◽  
N.R.R. Anbusagar ◽  
P. Sengottuvel

Improving the Material Removal Rate (MRR), reduce Tool Wear Rate (TWR), achieve the good Surface Finish (SF) and Over Cut (OC) are very demanding in Electrical Discharging Machining (EDM). This paper focused on performance of Silicon powder mixed with kerosene servotherm dielectric medium in EDM of Monel 400. The optimum range of Silicon powder, Graphite powder 6g mixes with the dielectric medium of kerosene servotherm (75:25) were developed experimentally. It was reported slightly more MRR, very low TWR, better OC and good surface finish (SF) in Monel 400.


2021 ◽  
Vol 63 (2) ◽  
pp. 182-189
Author(s):  
Sivasamy Alagarsamy ◽  
Manickam Ravichandran

Abstract The present study was carried out to analyze the effect of process parameters during EDM machining of AA7075-10 wt.-% TiO2 aluminum matrix composite (AMC). The composite was produced through stir casting. The EDM process parameters such as the electrode material (Cu, Br, EN-8), pulse current (5, 10 and 15 A), pulse ON time (300, 600 and 900 μs) and pulse OFF time (30, 60 and 90 μs) were chosen to study the effects on material removal rate, surface roughness and the electrode wear ratio. The experiment was carried out as per L27 orthogonal array based on Taguchi’s design of experiments. Signal-to-noise ratio and analysis of variance were used to identify the contribution of each input parameters on the output responses of the EDM process. The experimental results shows that pulse ON time and pulse current are the most significant factors for the material removal rate; pulse ON time and electrode material are the most influencing parameters for surface roughness and the electrode wear ratio.


Author(s):  
Balbir Singh ◽  
Jatinder Kumar ◽  
Sudhir Kumar

This paper presents the experimental investigation on the electro-discharge machining of aluminum alloy 6061 reinforced with SiC particles using sintered Cu–W electrode. Experiments have been designed as per central composite rotatable design, using response surface methodology. Machining characteristics such as material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR) have been investigated under the influence of four electrical process parameters; namely peak current, pulse on time, pulse off time, and gap voltage. The process parameters have been optimized to obtain optimal combination of MRR, EWR, and SR. Further, the influence of sintered Cu–W electrode on surface characteristics has been analyzed with scanning electron microscopy, energy dispersive spectroscopy, and Vicker microhardness tests. The results revealed that all the process parameters significantly affect MRR, EWR, and SR. The machined surface properties are modified as a result of material transfer from the electrode. The recast layer thickness is increased at higher setting of electrical parameters. The hardness across the machined surface is also increased by the use of sintered Cu–W electrode.


Manufacturing ◽  
2003 ◽  
Author(s):  
Scott F. Miller ◽  
Albert J. Shih

The development of new, advanced engineering materials and the needs for precise and flexible prototype and low-volume production have made wire electrical discharge machining (EDM) an important manufacturing process to meet such demand. This research investigates the effect of spark on-time duration and spark on-time ratio, two important EDM process parameters, on the material removal rate (MRR) and surface integrity of four types of advanced material: porous metal foams, metal bond diamond grinding wheels, sintered Nd-Fe-B magnets, and carbon-carbon bipolar plates. An experimental procedure was developed. During the wire EDM, five types of constraints on the MRR due to short circuit, wire breakage, machine slide speed limit, and spark on-time upper and lower limits have been identified. An envelope of feasible EDM process parameters is created and compared across different work-materials. Applications of such process envelope to select process parameters for maximum MRR and for machining of micro features are presented.


Author(s):  
Fred L. Amorim

The AISI P20 steel is applied by the tooling industry as material for injection molding tools. It is known that the EDM process parameters technology installed at the majority of CNC EDM machines do not cover some of the necessities of the tooling industry. So, the customers are required to develop their own process parameters. In order to provide useful technical information to the industry an experimental investigation on the EDM of the AISI P20 tool steel under finish machining has been carried out. The material removal rate Vw, volumetric relative wear v and workpiece surface texture Ra, which are representative of EDM performance aspects, were analyzed against the variation of some of the most important EDM electrical variables using copper tool electrodes under positive and negative polarity. The EDM machine generator was also programmed to actuate under isoenergetic mode and relaxation mode. The results are discussed and some appropriate parameters for EDM of AISI P20 are suggested.


2018 ◽  
Vol 5 (9) ◽  
pp. 18129-18134 ◽  
Author(s):  
Sanjay Kumar ◽  
Amit Kumar ◽  
Vinay Kumar ◽  
N.K. Singh

2013 ◽  
Vol 675 ◽  
pp. 365-369 ◽  
Author(s):  
Yan Cherng Lin ◽  
Han Ming Chow ◽  
Hai Ping Tsui ◽  
Yuan Feng Chen

The aim of this study is to investigate the machining characteristics of ultrasonic vibration assisted electrical discharge machining (EDM) process using gas media as the dielectric fluids. The process parameters were designed based on Taguchi method to conduct the experimental works. The main process parameters such as machining polarity, peak current, pulse duration, air pressure, working time, and servo reference voltage were chosen to determine their effects on machining performance in terms of material removal rate and surface roughness for SKD 61 tool steels. The experimental response values were transferred to signal-to-noise (S/N) ratios, and then the significant machining parameters associated with the machining performance were examined by analysis of variance (ANOVA). Therefore, the technique of ultrasonic vibration assisted EDM process in gas media was established with the concerning features related to environmentally friendly, high efficiency, and high machining quality to fit the demands of modern manufacturing applications.


Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 754 ◽  
Author(s):  
Asarudheen Abdudeen ◽  
Jaber E. Abu Qudeiri ◽  
Ansar Kareem ◽  
Thanveer Ahammed ◽  
Aiman Ziout

Electrical discharge machining (EDM) is an advanced machining method which removes metal by a series of recurring electrical discharges between an electrode and a conductive workpiece, submerged in a dielectric fluid. Even though EDM techniques are widely used to cut hard materials, low efficiency and high tool wear remain remarkable challenges in this process. Various studies, such as mixing different powders to dielectric fluids, are progressing to improve their efficiency. This paper reviews advances in the powder-mixed EDM process. Furthermore, studies about various powders used for the process and its comparison are carried out. This review looks at the objectives of achieving a more efficient metal removal rate, reduction in tool wear, and improved surface quality of the powder-mixed EDM process. Moreover, this paper helps researchers select suitable powders which are exhibiting better results and identifying different aspects of powder-mixed dielectric fluid of EDM.


2020 ◽  
Vol 66 (4) ◽  
pp. 243-253 ◽  
Author(s):  
Sanjay Sundriyal ◽  
Vipin ◽  
Ravinderjit Singh Walia

Near-dry electrical discharge machining (ND-EDM) is an eco-friendly process. In this study, an approach has been made to make the machining process more efficient than ND-EDM with the addition of metallic powder with the dielectric medium to machine EN-31 die steel. Powdermixed near-dry EDM (PMND-EDM) has several advantages over the ND-EDM or conventional electrical discharge machining (EDM) process, such as a higher material removal rate (MRR), fine surface finish (Ra), sharp cutting edge, lesser recast layer, and lower deposition of debris. The output response variables are MRR, Ra, residual stress (RS) and micro-hardness (MH) of the machined surfaces. Further study of the workpiece was performed, and a comparative study was conducted between ND-EDM and PMND-EDM. In this proposed method of machining, the MRR, Ra, and MH increased by 17.85 %, 16.36 %, and 62.69 % while RS was reduced by 56.09 %.


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