Powder Mixed Micro Electro Discharge Milling of Titanium Alloy: Investigation of Material Removal Rate

2011 ◽  
Vol 383-390 ◽  
pp. 1759-1763 ◽  
Author(s):  
Mohammad Yeakub Ali ◽  
Nur Atiqah Binti Abdul Rahman ◽  
Erniyati Binti Mohamad Aris

This paper presents effects of silicon carbide (SiC) powder in dielectric fluid of micro EDM on material removal rate (MRR). The aim is to identify the optimum level of SiC powder concentration and other micro EDM parameter for higher MRR. The work material was titanium alloy (Ti-6Al-4V) machined with tungsten carbide (WC) electrode by varying two machining parameters SiC powder concentrations and discharge energy. By using two factor four level factorial design of experiment, sixteen experiments were conducted. Data were analyzed by Design Expert® software. In this experimental investigation, maximum MRR of 7.3 µg/min was obtained for 24.75 g/l SiC powder concentration and 56.77 µJ discharge energy. The analysis of variance revealed that the SiC powder concentration in dielectric fluid on micro EDM has significant influence on MRR Ti-6Al-4V titanium alloy.

Author(s):  
Vikas Gohil ◽  
Yogesh M Puri

Electrical discharge turning is a unique form of electrical discharge machining process, which is being especially developed to generate cylindrical forms and helical profiles on the difficult-to-machine materials at both macro and micro levels. A precise submerged rotating spindle as a work holding system was designed and added to a conventional electrical discharge machine to rotate the workpiece. A conductive preshaped strip of copper as a forming tool is fed (reciprocate) continuously against the rotating workpiece; thus, mirror image of the tool is formed on the circumference of the workpiece. The machining performance of electrical discharge turning process is defined and influenced by its machining parameters, which directly affects the quality of the machined component. This study presents an investigation on the effects of the machining parameters, namely, pulse-on time, peak current, gap voltage, spindle speed and flushing pressure, on the material removal rate (MRR) and surface roughness (Ra) in electrical discharge turning of titanium alloy Ti-6Al-4V. This has been done by means of Taguchi’s design of experiment technique. Analysis of variance as well as regression analysis is performed on the experimental data. The signal-to-noise ratio analysis is employed to find the optimal condition. The experimental results indicate that peak current, gap voltage and pulse-on time are the most significant influencing parameters that contribute more than 90% to material removal rate. In the context of Ra, peak current and pulse-on time come up with more than 82% of contribution. Finally, the obtained predicted optimal results were verified experimentally. It was shown that the error values are all less than 6%, confirming the feasibility and effectiveness of the adopted approach.


2012 ◽  
Vol 159 ◽  
pp. 99-103
Author(s):  
Pei Pei Zhang ◽  
Zi Dong Yin ◽  
Xue Yan

Titanium alloy (TC18) is new style alloy (α+β). It possesses better performances than common titanium alloy. However, Titanium alloy (TC18) is still classified as difficult-to-machine materials for their poor machinability, which is attributed to relatively low modulus of elasticity, strong alloying tendency or chemical reactivity with cutting materials at higher temperatures and low conductivity of heat generated by the cutting action. Due to the poor machinability of the alloys, selecting of insert style is crucial for tool life and material removal rate. In this work, milling tests, using three kinds of inserts (KC522M, YD201 and SANDVIK 4240), were carried out on this kind of titanium alloy (TC18). The results of tests show that the material removal rate of insert KC522M is the highest, but its tool life is shorter compared with insert SANDVIK 4240. The material removal rate and tool life of insert YD201 do not draw the attention because both of them are relatively low. The abrasion speed of insert SANDVIK 4240 is slow and the efficiency is high, so it is ideal for machining titanium alloy (TC18). In addition, the optimal machining parameters of insert SANDVIK 4240 for milling titanium alloy (TC18) were also given in this paper.


2013 ◽  
Vol 465-466 ◽  
pp. 1329-1333 ◽  
Author(s):  
Abdus Sabur ◽  
Abdul Moudood ◽  
Mohammad Yeakub Ali ◽  
Mohammad Abdul Maleque

Micro-electro discharge machining (micro-EDM) technique, an advanced noncontact machining process, is used for structuring of nonconductive ZrO2 ceramic. In this study copper foil as a conductive layer is adhered on the workpiece surface to initiate the sparks and kerosene is used as dielectric for creation of continuous conductive pyrolytic carbon layer on the machined surface. Voltage (V) and capacitance (C) are considered as the parameters to investigate the process capability of machining parameters in continuous micro-EDM of ZrO2. Different voltage pulses are studied to examine the causes of lower material removal rate (MRR) in micro-EDM of nonconductive ceramics. The results showed that in micro-EDM of ZrO2 MRR increases with the increase of voltage and capacitance initially, but decreases at higher values and no significant materials are removed at capacitances higher than 1nF.


2017 ◽  
Vol 740 ◽  
pp. 125-132 ◽  
Author(s):  
Nagwa Mejid Elsiti ◽  
M.Y. Noordin

Cobalt-base alloys are normally applied to materials that require wear, corrosion, and heat resistance. Today, the alloy of cobalt–chromium–molybdenum (Co–Cr–Mo) is employed in aerospace and medical fields. Through the thermal erosion process of Electrical Discharge Machining (EDM), an electrically-produced spark vaporizes materials that are electrically conductive. This paper examines the viability of improvement of material removal rate in the micro-electric discharge machining of cobalt chromium molybdenum (Co-Cr-Mo) using Fe2O3 nanopowder-mixed dielectric fluid. For the purpose of this research, a copper electrode with 300μm diameter and positive polarity was utilized. The performance measures of the machining process were investigated regarding the material removal rate (MRR). For analysis of EDM of the CoCrMo, response surface methodology (RSM) was employed. Two concentrations of nanopowder were added to dielectric (2g/land 4g/l). Findings showed that if Iron oxide nanopowders (Fe2O3) exists in the dielectric, MRRcan be significantly improved. Amongst the two concentrations of powder-mixed micro-EDM, 2 g/l of nanopowder provided higher MRR in comparison with 4g/l and without powder cases.


1995 ◽  
Vol 117 (2) ◽  
pp. 142-151 ◽  
Author(s):  
Z. J. Pei ◽  
D. Prabhakar ◽  
P. M. Ferreira ◽  
M. Haselkorn

An approach to modeling the material removal rate (MRR) during rotary ultrasonic machining (RUM) of ceramics is proposed and applied to predicting the MRR for the case of magnesia stabilized zirconia. The model, a first attempt at predicting the MRR in RUM, is based on the assumption that brittle fracture is the primary mechanism of material removal. To justify this assumption, a model parameter (which models the ratio of the fractured volume to the indented volume of a single diamond particle) is shown to be invariant for most machining conditions. The model is mechanistic in the sense that this parameter can be observed experimentally from a few experiments for a particular material and then used in prediction of MRR over a wide range of process parameters. This is demonstrated for magnesia stabilized zirconia, where very good predictions are obtained using an estimate of this single parameter. On the basis of this model, relations between the material removal rate and the controllable machining parameters are deduced. These relationships agree well with the trends observed by experimental observations made by other investigators.


2014 ◽  
Vol 592-594 ◽  
pp. 516-520 ◽  
Author(s):  
Basil Kuriachen ◽  
Jose Mathew

Micro EDM milling process is accruing a lot of importance in micro fabrication of difficult to machine materials. Any complex shape can be generated with the help of the controlled cylindrical tool in the pre determined path. Due to the complex material removal mechanism on the tool and the work piece, a detailed parametric study is required. In this study, the influence of various process parameters on material removal mechanism is investigated. Experiments were planned as per Response Surface Methodology (RSM) – Box Behnken design and performed under different cutting conditions of gap voltage, capacitance, electrode rotation speed and feed rate. Analysis of variance (ANOVA) was employed to identify the level of importance of machining parameters on the material removal rate. Maximum material removal rate was obtained at Voltage (115V), Capacitance (0.4μF), Electrode rotational Speed (1000rpm), and Feed rate (18mm/min). In addition, a mathematical model is created to predict the material removal


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