Performance and Analysis of Silicon Mixed Kerosene Servotherm in EDM of Monel 400

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.

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):  
Arnab Das ◽  
Deepak Kumar ◽  
Mohan Kumar ◽  
Vivek Bajpai

Abstract Ti6Al4V is a highly favorable material in biomedical, aerospace and many other industries. However, rapid tool wear during machining has made Ti6Al4V into a difficult-to-machine material. Electrochemical machining may be a solution to that challenge. Moreover, high chemical affinity and formation of oxide layer over the surface have limited the application electrochemical machining for Ti6Al4V. In this paper, an experimental approach of electrochemical micro turning of Ti6Al4V has been described. The electrolyte was 10% aqueous solution of NaOH and the tool was SS 310. For each and every experiment workpiece rotational speed and machining time were kept constant. Constant DC voltage was applied and the inter-electrode gap between tool and workpiece was kept constant for each experiment. Experiments were performed using two different levels of applied voltage, axial feed rate and inter-electrode gap. Their effects over MRR and surface roughness have been determined. Additionally, the optimum working condition was determined in order to maximize MRR and minimize surface roughness. For each experiment, acceptable material removal and good surface finish have been achieved. The maximum surface roughness (Ra) was found 1.128 μm in experiment 1. The utilization of NaOH solution has resulted in controlled electrolyzing current, controlled material removal and therefore, good surface finish.


2020 ◽  
Vol 38 (3A) ◽  
pp. 295-307
Author(s):  
Rasha R. Elias

In this paper, Artificial Neural Network was adopted to predict the effect of current, the concentration of aluminum oxide (Al2O3) and graphite Nanopowders in dielectric fluid for the machining of Carbon steel 304 using Electrical Discharge Machining (EDM). The process variables were utilized to find their effect on Material Removal Rate (MRR), Surface Roughness (SR), and Tool Wear Rate (TWR). It was revealed from the experimental work that the addition of aluminum oxide and graphite Nanopowders into dielectric fluid maximizing MRR, minimized the SR and TWR at various variables. Minitab software was used in the design of experiments. Analysis of the process outputs of EDM indicates that graphite powder concentration greatly influencing SR also the discharge current whereas the current and Nanopowders concentration has more percentage of influence on the TWR and MRR.


2005 ◽  
Vol 20 (2) ◽  
pp. 504-520 ◽  
Author(s):  
Honglin Zhu ◽  
Dale E. Niesz ◽  
Victor A. Greenhut ◽  
Robert Sabia

A series of abrasives with various hardness values including monocrystalline and polycrystalline diamond, α- and γ-alumina, zirconia, ceria, and silica were used to examine the concept of chemical-assisted polishing for finishing the (0001), c-plane (basal plane), of sapphire. Diaspore, a monohydrate of alumina, was also evaluated. Atomic force microscopy suggested that the hydrated layer of the c-plane surface was about 1 nm thick. Polishing experiments were designed to determine whether the chemically modified surface hydration layer forms on the basal plane in water. The results indicate that harder abrasives do not necessarily cause faster material removal and better surface finish for similar abrasive particle size. Abrasives with hardness equal to or less than sapphire such as α-Al2O3 and γ-Al2O3 achieved the best surface finish and greatest efficiency of material removal. It is proposed that the (0001) c-plane sapphire surface was modified by water to form a thin hydration layer with structure and hardness close to diaspore. This reaction layer can be removed by an abrasive that is softer than sapphire but harder than the reaction layer. α-Al2O3 was particularly effective. This result is attributed to adhesion between identical reaction layers on the basal planes of the alumina abrasive and the sapphire. This demonstrates that high removal rates and good surface finish can be achieved without costly diamond polishing.


Author(s):  
Sagil James ◽  
Sharadkumar Kakadiya

Shape Memory Alloys are smart materials that tend to remember and return to its original shape when subjected to deformation. These materials find numerous applications in robotics, automotive and biomedical industries. Micromachining of SMAs is often a considerable challenge using conventional machining processes. Micro-Electrical Discharge Machining is a combination of thermal and electrical processes, which can machine any electrically conductive material at micron scale independent of its hardness. It employs dielectric medium such as hydrocarbon oils, deionized water, and kerosene. Using liquid dielectrics has adverse effects on the machined surface causing cracking, white layer deposition, and irregular surface finish. These limitations can be minimized by using a dry dielectric medium such as air or nitrogen gas. This research involves the experimental study of micromachining of Shape Memory Alloys using dry Micro-Electrical Discharge Machining process. The study considers the effect of critical process parameters including discharge voltage and discharge current on the material removal rate and the tool wear rate. A comparison study is performed between the Micro-Electrical Discharge Machining process with using the liquid as well as air as the dielectric medium. In this study, microcavities are successfully machined on shape memory alloys using dry Micro-Electrical Discharge Machining process. The study found that the dry Micro-Electrical Discharge Machining produces a comparatively better surface finish, has lower tool wear and lesser material removal rate compared to the process using the liquid as the dielectric medium. The results of this research could extend the industrial applications of Micro Electrical Discharge Machining processes.


2016 ◽  
Vol 40 (3) ◽  
pp. 331-349 ◽  
Author(s):  
S. Sivasankar ◽  
R. Jeyapaul

This research work concentrates on Electrical Discharge Machining (EDM) performance evaluation of ZrB2- SiC ceramic matrix composites with different tool materials at various machining parameters. Monolithic ZrB2 possesses lower relative density (98.72%) than composites. ZrB2 with 20 Vol.% of SiC possesses 99.74% of the relative density with improved hardness values. Bend strength and Young’s modulus increase with SiC addition until it reaches 20 Vol% and then decreasing. EDM performance on tool materials of tungsten, niobium, tantalum, graphite and titanium at various levels of pulse on time and pulse off time are analyzed. Graphite produces the best Material removal rate (MRR) for all the workpieces. Tool wear rate decreases with melting point and thermal conductivity of the tool material.


Author(s):  
Santosh Kumar Sahu ◽  
Saurav Datta

Inconel 718 is a nickel-based super alloy widely applied in aerospace, automotive, and defense industries. Low thermal conductivity, extreme high temperature strength, strong work-hardening tendency make the alloy difficult-to-cut. In contrast to traditional machining, nonconventional route like electro-discharge machining is relatively more advantageous to machine this alloy. However, low thermal conductivity of Inconel 718 restricts electro-discharge machining from performing well. In order to improve the electro-discharge machining performance of Inconel 718, powder-mixed electro-discharge machining was reported in this paper. It was carried out by adding graphite powder to the dielectric media in consideration with varied peak discharge current. The morphology and topographical features of the machined surface including surface roughness, crack density, white layer thickness, metallurgical aspects (phase transformation, crystallite size, microstrain, and dislocation density), material migration, residual stress, microindentation hardness, etc. were studied and compared with that of the conventional electro-discharge machining. Additionally, effects of peak discharge current were discussed on influencing different performance measures of powder-mixed electro-discharge machining. Material removal efficiency and tool wear rate were also examined. Use of graphite powder-mixed electro-discharge machining was found to be better in performance for improved material removal rate, superior surface finish, reduced tool wear rate, and reduced intensity as well as severity of surface cracking. Lesser extent of carbon migration onto the machined surface as observed in powder-mixed electro-discharge machining in turn reduced the formation of hard carbide layers. As compared to the conventional electro-discharge machining, graphite powder-mixed electro-discharge machining exhibited relatively less microhardness and residual stress at the machined surface.


Author(s):  
Arun Kumar Rouniyar ◽  
Pragya Shandilya

Magnetic field assisted powder mixed electrical discharge machining is a hybrid machining process with suitable modification in electrical discharge machining combining the use of magnetic field and fine powder in the dielectric fluid. Aluminum 6061 alloy has found highly significance for the advanced industries like automotive, aerospace, electrical, marine, food processing and chemical due to good corrosion resistance, high strength-to-weight ratio, ease of weldability. In this present work, magnetic field assisted powder mixed electrical discharge machining setup was fabricated and experiments were performed using one factor at a time approach for aluminum 6061 alloy. The individual effect of machining parameters namely, peak current, pulse on time, pulse off time, powder concentration and magnetic field on material removal rate and tool wear rate was investigated. The effect of peak current was found to be dominant on material removal rate and tool wear rate followed by pulse on time, powder concentration and magnetic field. Increase in material removal rate and tool wear rate was observed with increase in peak current, pulse on time and a decrease in pulse off time, whereas, for material removal rate increases and tool wear rate decreases up to the certain value and follow the reverse trend with an increase in powder concentration. Material removal rate was increased and tool wear rate was decreased with increase in magnetic field.


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