Experimental Investigations into Traveling Wire Electrochemical Spark Machining (TW-ECSM) of Composites

1991 ◽  
Vol 113 (1) ◽  
pp. 75-84 ◽  
Author(s):  
V. K. Jain ◽  
P. Sreenivasa Rao ◽  
S. K. Choudhary ◽  
K. P. Rajurkar

Fiber reinforced composites, though relatively new, have already become important engineering materials. So far the main emphasis of research has been on the development of materials, but nowadays more attention is being paid to the industrial manufacture of products made of composites. Conventional machining methods and some unconventional machining methods like laser beam machining (LBM) and water jet machining (WJM) cannot be effectively applied for machining of composites due to the resulting problems of air borne dust, tool wear, and thermal damage. Recently electrochemical spark machining (ECSM) has been applied for the cutting and drilling of holes in composites. The success achieved in the application of ECSM for cutting of composites has stimulated interest in exploring the prospects of use of traveling wire electrochemical spark machining (TW-ECSM) process for cutting of composites. An apparatus for TW-ECSM is designed and fabricated in the laboratory. The results about the feasibility of the process and its performance during machining of composites are presented in this paper. Experiments are carried out on glass-epoxy and kevlar-epoxy composites, using sodium hydroxide (NaOH) as electrolyte. The wire and the workpiece were kept in physical contact with each other by the use of a gravity feed mechanism. The effects of voltage and concentration of the electrolyte on material removal rate, average diametral overcut, tool wear rate, and wire erosion ratio are reported. The theoretical analysis of the mechanism of the process identifies the thermo-mechanical phenomena as the main source of material removal in ECSM.

2011 ◽  
Vol 3 (5) ◽  
pp. 211-213
Author(s):  
Dr. G.Harinath Gowd ◽  
◽  
M. Gunasekhar Reddy ◽  
Bathina Sreenivasulu ◽  
Rayudu Peyyala

2020 ◽  
Vol 38 (9A) ◽  
pp. 1406-1413
Author(s):  
Yousif Q. Laibia ◽  
Saad K. Shather

Electrical discharge machining (EDM) is one of the most common non-traditional processes for the manufacture of high precision parts and complex shapes. The EDM process depends on the heat energy between the work material and the tool electrode. This study focused on the material removal rate (MRR), the surface roughness, and tool wear in a 304 stainless steel EDM. The composite electrode consisted of copper (Cu) and silicon carbide (SiC). The current effects imposed on the working material, as well as the pulses that change over time during the experiment. When the current used is (8, 5, 3, 2, 1.5) A, the pulse time used is (12, 25) μs and the size of the space used is (1) mm. Optimum surface roughness under a current of 1.5 A and the pulse time of 25 μs with a maximum MRR of 8 A and the pulse duration of 25 μs.


2020 ◽  
Vol 38 (10A) ◽  
pp. 1489-1503
Author(s):  
Marwa Q. Ibraheem

In this present work use a genetic algorithm for the selection of cutting conditions in milling operation such as cutting speed, feed and depth of cut to investigate the optimal value and the effects of it on the material removal rate and tool wear. The material selected for this work was Ti-6Al-4V Alloy using H13A carbide as a cutting tool. Two objective functions have been adopted gives minimum tool wear and maximum material removal rate that is simultaneously optimized. Finally, it does conclude from the results that the optimal value of cutting speed is (1992.601m/min), depth of cut is (1.55mm) and feed is (148.203mm/rev) for the present work.


Author(s):  
Mayank Srivastava ◽  
Pulak M Pandey

The present experimental investigation attempts to understand and address the effect of ultrasonic vibrations on material removal in the polishing of silicon wafers (1 0 0). The requisite finishing experimentations were performed on an indigenously developed experimental arrangement of double-disc chemical assisted magnetorheological finishing (DDCAMRF) process with longitudinal vibrations. The MR fluid used in the experiments consists of a water-based suspension prepared by mixing suitable amounts of carbonyl iron particles (CIPs), abrasive particles, and additives or stabilizers. The prepared MR fluid uses both mechanics and chemistry to finish the silicon surface. Mechanics is mainly responsible for micro-scratching of silicon surface, which gets “softened” by hydration utilizing DI water in the MR fluid. In this study, the ‘response surface methodology (RSM)’ was chosen for designing the experiments to evaluate the significance of different process factors, namely polishing speed, abrasive concentration, and ultrasonic power on the material removal rate (MRR) in DDCAMRF process. The material removed from the wafer surface was measured using the precision digital weighing balance. It was observed that the MRR was found to increase with the increase in various process factors used. Further, analysis of variance (i.e., ANOVA) technique with a 95% confidence interval was performed to analyze the significant contribution of different process factors on MRR. The validation of developed model was done by performing experiments on random and optimized set of process factors. From, the statistical investigation it was discovered that ultrasonic power has highest contribution of 57.9% on MRR, followed by the polishing speed (13.3%), and abrasive concentration (12.5%). Furthermore, a genetic algorithm optimization tool was utilized to obtain optimum set of process parameters to maximize MRR.


Author(s):  
D. S. Sai Ravi Kiran ◽  
Alavilli Sai Apparao ◽  
Vempala GowriSankar ◽  
Shaik Faheem ◽  
Sheik Abdul Mateen ◽  
...  

This paper investigates the machinability characteristics of end milling operation to yield minimum tool wear with the maximum material removal rate using RSM. Twenty-seven experimental runs based on Box-Behnken Design of Response Surface Methodology (RSM) were performed by varying the parameters of spindle speed, feed and depth of cut in different weight percentage of reinforcements such as Silicon Carbide (SiC-5%, 10%,15%) and Alumina (Al2O3-5%) in alluminium 7075 metal matrix. Grey relational analysis was used to solve the multi-response optimization problem by changing the weightages for different responses as per the process requirements of quality or productivity. Optimal parameter settings obtained were verified through confirmatory experiments. Analysis of variance was performed to obtain the contribution of each parameter on the machinability characteristics. The result shows that spindle speed and weight percentage of SiC are the most significant factors which affect the machinability characteristics of hybrid composites. An appropriate selection of the input parameters such as spindle speed of 1000 rpm, feed of 0.02 mm/rev, depth of cut of 1 mm and 5% of SiC produce best tool wear outcome and a spindle speed of 1838 rpm, feed of 0.04 mm/rev, depth of cut of 1.81 mm and 6.81 % of SiC for material removal rate.


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.


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):  
Jun-chen Li ◽  
Wen-hu Wang ◽  
Rui-song Jiang ◽  
Xiao-fen Liu ◽  
Huang Bo ◽  
...  

Abstract The IC10 superalloy material is one of the most important materials for aero-engine turbine blade due to its excellent performances. However, it is difficult to be machined because of its special properties such as terrible tool wear and low machined efficiency. The creep feed grinding is widely used in machining IC10 superalloy due to the advance in reducing tool wear, improving material removal rate and surface quality. The creep feed grinding is a promising machining process with the advantages of high material removal rate due to large cutting depth, long cutting arc and very slow workpiece, and its predominant features might have significant influence on the grinding force and surface quality for the workpiece. Hence, it is of great importance to study the grinding force and surface integrity in creep feed grinding IC10 superalloy. In this paper, a series of orthogonal experiments have been carried out and the effects of grinding parameters on the grinding force and the surface roughness are analyzed. The topographies and defects of the machined surface were observed and analyzed using SEM. The results of the experiments show that the tangential force is decreased with the workpiece speed increasing. However, there is no significant change in tangential force with the increasing of grinding depth and wheel speed. The normal force is decreased with the workpiece speed increasing when the workpiece speed is less than 150 mm/min, but when the workpiece speed is more than 150 mm/min the normal force is increased tardily. Moreover, the normal force is increased sharply with the increase of grinding depth and is increased slowly with the increase of wheel speed. In general, the surface roughness is increased with workpiece speed and grinding depth increasing, while the trend of increase corresponding that of workpiece speed is more evident. The value of the surface roughness is decreased with wheel speed increasing. And it is found out that the main defect is burning of the IC10 superalloy material in creep feed grinding by energy spectrum analysis of some typical topography in this study.


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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