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1. International INTERNATIONAL Journal of Mechanical JOURNAL Engineering OF and MECHANICAL Technology (IJMET), ISSN ENGINEERING 0976 6340(Print), ISSN 0976 6359(Online), Volume 5, Issue 7, July (2014), pp. 80-100 IAEME AND TECHNOLOGY (IJMET) ISSN 0976 6340 (Print) ISSN 0976 6359 (Online) Volume 5, Issue 7, July (2014), pp. 80-100 IAEME: www.iaeme.com/IJMET.asp Journal Impact Factor (2014): 7.5377 (Calculated by GISI) www.jifactor.com 80 IJMET I A E M E EFFECT OF VIBRATION ON MICRO-ELECTRO-DISCHARGE MACHINING Amol S. Todkar1, Dr. M.S. Sohani2, Prashant R. Patil3, P. N. Deshmukh4 1, 3, 4(Department of Mechanical Engineering, TKIET, Warananagar, Kolhapur, India) 2(Professor, Department of Mechanical Engineering, AITM, Belgaum, India) ABSTRACT The Principal objective of the research work is decided to carryout Response Surface Methodology (RSM) based investigations into the effect of Voltage, Capacitance and work piece vibration Frequency, amplitude on different materials. The RSM based mathematical models of Material Removal Rate (MRR) and Tool Wear Rate (TWR) have been developed using the data obtained through Central Composite Design (CCD). The Analysis of Variance (ANOVA) was performed along with Fishers statistical test (F-test) to verify the lack-of-fit and adequacy of the developed mathematical models for the desired confidence interval. The ANOVA table includes sum of squares (SS), degrees of freedom (DF) and mean square (MS). In ANOVA, the contributions for SS is from the first order terms (linear), the second order terms (square), the interaction terms, lack of fit and the residual error. The lack of fit component is the deviation of the response from fitted surface, whereas the residual error is obtained from the replicated points at the center. The MS are obtained by dividing the SS of each of the sources of variation by the respective DF. The p-value is the smallest level of significance at which the data are significant. The Fishers variation ratio (F-ratio) is the ratio of the MS of the lack of fit to the MS of the pure experimental error. As per the ANOVA technique, the model developed is adequate within the confidence interval if calculated value of F-ratio of lack of fit to pure error does not exceed the standard tabulated value of F-ratio and the F-values of model should be more than the F-critical for a confidence interval. Further, conformation test was performed to ascertain the accuracy of the developed models. The entire research work is experiment oriented and the conclusions are drawn based on graphical analysis of experimental results. The research work carried out reveals that the findings are encouraging in establishing the effect of Voltage, Capacitance and work piece vibration Frequency, amplitude on different materials EDM drilling process performance characteristics. The results of this investigations can be adopted in deciding the optimal values of input process parameters EDM drilling process.

2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 6340(Print), ISSN 0976 6359(Online), Volume 5, Issue 7, July (2014), pp. 80-100 IAEME Keywords: Electrical Discharge Machining (EDM), Central Composite Design (CCD), Material Removal Rate (MRR), Tool Wear Rate (TWR), Response Surface Methodology (RSM). Analysis of Variance (ANOVA). 81 Abbreviations I Discharge current ton Pulse on time toff Pulse of time A Tool area MRR Material removal rate TWR Tool wear rate WRW Workpiece removal weight TWW Tool wear weight Density T Machining time R.No Run number F Fisher ratio R2 Coefficient of determination INTRODUCTION The basis of controlling the micro electro-discharge machining (EDM) process mostly relies on empirical methods largely due to the stochastic nature of the sparking phenomenon involving both electrical and nonelectrical processes parameters. Thus the performance of micro electro-discharge machining (EDM) process is commonly evaluated in the terms of Material Removal Rate (MRR) and Tool Wear Rate (TWR); and to compute MRR and TWR mathematical models are developed. Modeling and analysis of Material Removal Rate (MRR) and Tool Wear Rate(TWR) with the effect of processes parameters like Voltage, Capacitance & Amplitude, Frequency of Vibration on different workpiece thickness is described in this investigation. Conventional Statistical Regression analyses based mathematical models have been developed to establish the input out put relationships. Material Removal Rate (MRR) and Tool Wear Rate(TWR) mathematical models have been developed using the data obtained through Central Composite Design(CCD) The lack-of-fit and adequacy of the developed mode was verified by applying Analysis of Variance (ANOVA).Further the conformation tests were performed to ascertain the accuracy of the developed models.[1] EXPERIMENTAL DETAILS Experimental set-up In the present investigation, the experiments were performed in Electronica machine tool EDM Drill (Rapid drill -II) machine. Fig. 2 shows a photograph of EDM machine. The specifications of micro EDM machine are shown in the Table 1.1 The electrolytic copper is used as a tool material because of its higher MRR and less TWR, it also yields a better surface finish. The electrolytic copper tools with different size used to erode water quenched steel k 340 workpiece. The impulse flushing of tap water (dielectric fluid) was employed throughout the experimental investigations. The other quantitative and qualitative micro EDM processes parameters were kept constant for given set of trials.

3. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 6340(Print), ISSN 0976 6359(Online), Volume 5, Issue 7, July (2014), pp. 80-100 IAEME 82 Fig. 1: Schematic diagram of the developed vibration unit Vibration Unit A simple vibration device has been designed and developed. In order to create a low frequency oscillation on the work piece (Fig.4). An electromagnet is used as the actuator. The electric power is supplied periodically to the electromagnet with the help of a power transistor switch. The on-off sequence of the power transistor is controlled by a frequency controllable pulse generator. When the switch is kept on, the electricity flowing through the circuit causes the electromagnet to be energized, which triggers a pull action on the vibration pad. The flexure beams are bent at that time. Again, the electromagnet is de-energized when the transistor switch is turned off, causing the flexure beams to release and push the vibration pad in upward direction. In this way, a low frequency vibration is induced on the work piece during micro-EDM. Fig.2: Photograph of electronica machine tool EDM drill (rapid drill -ii)

4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 6340(Print), ISSN 0976 6359(Online), Volume 5, Issue 7, July (2014), pp. 80-100 IAEME 83 Table 1.1: Electronica machine tool edm drill (rapid drill) Technical Specifications Machine Tool Rapid drill II Work table 450 x 300 mm (Granite) X & Y axes travel 350, 250 mm Z axis travel 350 + 300 mm Max. Electrode length 400 mm Size of electrode dia. 0.3-3.0 mm Max. drill depth 300 mm Max. coolant pressure 6 MPA Max. weight of the workpiece 350 kg Connected load 3 kVA Work tank 800 x 450 mm Input power supply 3 phase, AC 415 V*, 50Hz Net Weight 750 kg Machine foot print 950 x 850 x 1980 mm Max. machining current 30 A TECHNOLOGY Job material Steel/Brass/Aluminium/Carbide/other conducting materials Dielectric Tap water/ Coolant soap Max. drilling speed 20-60mm/min (dia0.5 mm) Materials used for the experiments Work piece material 1) Work piece material used for the experiment was K340 steel with the density of 7.77g/cm and After quenching of 1040 C and 520 ~ 530 C high temperature tempering, the hardness of HRC up to 62 to 63. Table 4.2 depicts the chemical composition of K340 steel. Table 1.2: Chemical Composition Of K340 Steel By Weight Percentage C Si Mn Mo V Cr P 1.00 0.91 0.32 2.00 0.28 8.00 0.007 2) Iron sinter is the thermally agglomerated substance formed by heating a variable mixture of iron ores, finely divided coke, limestone, blast furnace dust, steelmaking dust, mill scale and other miscellaneous iron bearing materials in the temperature range 1315 to 1480C. The product iron sinter is used exclusively as a burden material in the production of iron in the blast furnace. The

5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 6340(Print), ISSN 0976 6359(Online), Volume 5, Issue 7, July (2014), pp. 80-100 IAEME identity of iron sinter is summarized in Table 1.The typical [sameness] specification for Iron Sinter is given in Table 2. 84 Table 1.3: Identity Of Iron Sinter Chemical name Iron, sinter IUPAC name Other names (usual name, trade name, Iron sinter abbreviation) EINECS No. 265-9979 CAS name and CAS No. 65996-669 Other identity code: Related CAS No. Hematite (Fe2O3) 1317-608 Molecular formula Fe2O3 Structural information (Crystal lattice) Minerals of identical or similar composition Hematite MW (g/mole) MW (g/mole) 159.69 Table 1.4: Sameness Specification For Iron Sinter Constituent Typical range, % m/m Fe2O3 >55 FeO

30120140507009 2

Technology

central composite design

tool wear rate

material removal rate

material removal rate

work piece

international journal

confidence interval

iron sinter