The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
D. Chakradhar - One of the best experts on this subject based on the ideXlab platform.
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ANFIS modelling of mean Gap Voltage variation to predict wire breakages during wire EDM of Inconel 718
CIRP Journal of Manufacturing Science and Technology, 2020Co-Authors: P M Abhilash, D. ChakradharAbstract:Abstract The study aims to correlate the mean Gap Voltage variation and wire breakage occurrences during the wire EDM of Inconel 718. A novel approach to predict the wire breakage is introduced by considering the mean Gap Voltage variation (ΔVm) as an indicator of the instabilities in the spark Gap. Such instabilities are regarded as the primary reason for wire breakages and inferior part quality of wire electric discharge machined components. The parameter ΔVm is a process data obtained as the difference between servo Voltage and mean Gap Voltage (Vm). It was found experimentally that if the value of ΔVm crosses a threshold limit, the process interruptions through wire breakages were observed. In order to predict the wire breakage situations, the study models ΔVm using adaptive neuro fuzzy inference system (ANFIS). Based on central composite design (CCD) of response surface methodology (RSM), 31 experiments were conducted and ΔVm is recorded as the response. The input parameters considered were pulse on time, pulse off time, servo Voltage and wire feed rate. The ANFIS model was found very accurate in predicting ΔVm, based on which wire breakage alerts can be given. The capability of the model is further confirmed by verification experiments. EDS and microstructural analysis further revealed the effect of ΔVm on wire wear and part quality. Higher value of ΔVm resulted in greater wire wear and inferior part quality. The surface finish and flatness error of machined parts were measured to compare the part quality.
P M Abhilash - One of the best experts on this subject based on the ideXlab platform.
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ANFIS modelling of mean Gap Voltage variation to predict wire breakages during wire EDM of Inconel 718
CIRP Journal of Manufacturing Science and Technology, 2020Co-Authors: P M Abhilash, D. ChakradharAbstract:Abstract The study aims to correlate the mean Gap Voltage variation and wire breakage occurrences during the wire EDM of Inconel 718. A novel approach to predict the wire breakage is introduced by considering the mean Gap Voltage variation (ΔVm) as an indicator of the instabilities in the spark Gap. Such instabilities are regarded as the primary reason for wire breakages and inferior part quality of wire electric discharge machined components. The parameter ΔVm is a process data obtained as the difference between servo Voltage and mean Gap Voltage (Vm). It was found experimentally that if the value of ΔVm crosses a threshold limit, the process interruptions through wire breakages were observed. In order to predict the wire breakage situations, the study models ΔVm using adaptive neuro fuzzy inference system (ANFIS). Based on central composite design (CCD) of response surface methodology (RSM), 31 experiments were conducted and ΔVm is recorded as the response. The input parameters considered were pulse on time, pulse off time, servo Voltage and wire feed rate. The ANFIS model was found very accurate in predicting ΔVm, based on which wire breakage alerts can be given. The capability of the model is further confirmed by verification experiments. EDS and microstructural analysis further revealed the effect of ΔVm on wire wear and part quality. Higher value of ΔVm resulted in greater wire wear and inferior part quality. The surface finish and flatness error of machined parts were measured to compare the part quality.
David R. Jackson - One of the best experts on this subject based on the ideXlab platform.
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Time-Domain Pulse Propagation on a Microstrip Transmission Line Excited by a Gap Voltage Source
2006 IEEE MTT-S International Microwave Symposium Digest, 2006Co-Authors: William L. Langston, Jeffery T. Williams, David R. Jackson, Francisco MesaAbstract:Time-domain pulse propagation on microstrip transmission lines excited by a finite-Gap Voltage source is investigated with special attention given to the dispersive effects associated with the individual components of the transmission-line current. High-frequency effects due to leaky modes are of particular interest. The results show that dispersion can be quite different and more severe than that predicted by the bound mode alone.
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Effects of Dielectric and Conductor Losses on the Current Spectrum Excited by a Gap Voltage Source on a Printed-Circuit Line
2006 IEEE MTT-S International Microwave Symposium Digest, 2006Co-Authors: J. Bernal, Francisco Mesa, David R. JacksonAbstract:In the past, the high-frequency current excited on a lossless microstrip line by a Gap Voltage source has been examined. The present work studies some interesting effects that practical conductor and dielectric loss have on the current. These loss effects have been neglected in past analyses, although all practical microstrip lines have both conductor and dielectric loss. Our analysis and results reveal that the loss attenuates the bound mode of propagation in the expected manner (causing it to decay exponentially), while the continuous-spectrum current is hardly affected by the loss. The consequence of this is that the nature of the strip current far away from the source is dramatically affected by the presence of loss. The type of spurious effects that are observed due to the interference between the bound mode and the continuous-spectrum currents may also be significantly affected by the loss. In the lossy case, the spurious effects may actually increase with distance from the source.
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Crosstalk between two microstrip lines excited by a Gap Voltage source
IEEE Transactions on Microwave Theory and Techniques, 2004Co-Authors: J. Bernal, Francisco Mesa, David R. JacksonAbstract:The crosstalk between two microstrip lines is studied when one of the lines (the source line) is excited by a Gap Voltage source. In particular, the current induced on the passive line (the victim line) due to electromagnetic coupling to the source line is studied as a function of line separation and frequency for different permittivities. Results are also presented for the case of the source line excited by a vertical electric dipole to explore the effect of different source excitations on the crosstalk current. The current is calculated using a semianalytical method, which allows for an examination of the constituent current components on the lines (the bound-mode and continuous-spectrum currents) so that the physical mechanisms of coupling can be explored. The calculation is performed in an efficient manner using a mixed-potential integral-equation formulation with complex images.
Mohammad Yeakub Ali - One of the best experts on this subject based on the ideXlab platform.
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Analysis of Corner Radius in Dry Micro WEDM
International Journal of Mechanical Engineering and Robotics Research, 2020Co-Authors: Ahmed Ghalib Khan Chowdhury, Mohammad Yeakub Ali, Asfana BanuAbstract:Dry micro WEDM is a machining process where gas is used as the dielectric medium instead of liquid. This process favored for its environmental friendly nature and its ability in machining complex intricate shapes with great precision. Regardless of its high precision, the machining precision of cutting sharp corners cannot be satisfied. Therefore, the purpose of this paper is to analyze the process parameters; Gap Voltage, wire tension, and air dielectric pressure to find the optimal parameters to minimize the radius during the sharp corner cutting of stainless steel workpiece. Compressed air was used as the dielectric fluid, whereas the electrode was a 70 micrometer tungsten wire. The experiments were design using full factorial method while the data were analyzed using analysis of variance (ANOVA). Based on ANOVA, Gap Voltage and wire tension had a major influence on the corner radius. The optimum parameters for minimum corner radius were found to be 85 V Gap Voltage, 0.16 N wire tension, and 0 MPa dielectric pressure.
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dimensional accuracy in dry micro wire electrical discharge machining
Journal of Mechanical Engineering and Sciences, 2018Co-Authors: Mohammad Yeakub Ali, Muhammad Salehan, Asfana Banu, Erry Yulian Triblas Adesta, Muataz Hazza Faizi Al Hazza, Muhammad ShaffiqAbstract:Dimensional accuracy is important in fabricating miniaturized product in order to reduce the material waste and machining cost as well as to achieve a better quality product. This paper presents the analysis and modelling of dimensional accuracy in dry micro wire electrical discharge machining with control parameters of Gap Voltage and wire tension. The investigation was performed on stainless steel using integrated multi-process micro machine tools DT 110 with compressed air as the dielectric fluid and tungsten as the wire electrode. The dimensional accuracy was determined through kerf width differences of the machined slots. The kerf width was measured using scanning electron microscope. Full factorial was used to design the experiment while analysis of variance (ANOVA) was used to analyse the results as well as to evaluate the adequacy of the developed model. Based on ANOVA, both parameters; Gap Voltage and wire tension have high influence on kerf width differences. The optimum machining parameters for minimum kerf width differences were found to be 85 V Gap Voltage and 10 % wire tension. The developed model is adequate since the percentage error (2.13 %) is relatively small. It is recommended that different type of gases should be used for further investigation in order to determine the accuracy of the dry micro wire EDM.
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Micro wire electro discharge grinding: optimization of material removal rate and surface roughness
IOP Conference Series: Materials Science and Engineering, 2017Co-Authors: Mohammad Yeakub Ali, Mohamed Abd Rahman, Rosmarina NordinAbstract:This paper presents the analysis and modelling of material removal rate (MRR) and surface roughness (Ra) by micro wire electro discharge grinding (micro-WEDG) with control parameter of Gap Voltage, feed rate, and spindle speed. The data were analyzed and empirical models are developed. The optimized values of MRR and Ra are 0.051 mm3/min and 0.25 μm respectively with 110 V Gap Voltage, 38 μm/s feed rate, and 1315 rpm spindle speed. The analysis showed that Gap Voltage has significant effect on material removal rate while spindle speed has significant effect on surface roughness.
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Material Removal Rate of Zirconia in Electro Discharge Micromachining
Advanced Materials Research, 2015Co-Authors: Banu Asfana, Abdul Rahman Mohamed, Mohammad Yeakub Ali, Wayne N.p. HungAbstract:This paper investigates the material removal rate (MRR) in electro discharge micromachining (micro-EDM) of zirconia. Experimental investigation is carried out with 800 μm diameter tungsten electrode with two varying parameters rotational speed and Gap Voltage. The MRR data are analyzed and an empirical model is developed using Design Expert software. The optimum parameters for maximum MRR are found to be 375 rpm rotational speed and 80 V Gap Voltage.
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Influence of Energy Parameters of Micro WEDM on Kerf
Advanced Materials Research, 2012Co-Authors: Mohammad Yeakub Ali, Willey Yun Hsien Liew, S.a. Gure, Banu AsfanaAbstract:This paper presents the estimation of kerf width in micro wire electrical discharge machining (micro WEDM) in terms of machining parameters of capacitance and Gap Voltage. An empirical model is developed by the analysis of variance (ANOVA) of experimental data. Using a wire electrode of 70 µm diameter, a minimum kerf width is found to be 92 µm for the micro WEDM parameters of 0.01 µF capacitance and 90.25 V Gap Voltage. Around 30% increament of the kerf is found to be high. The analysis also revealed that the capacitance is more influential parameter than Gap Voltage on kerf width produced by micro WEDM. As the Gap Voltage determines the breakdown distance and affects the wire vibration, the wire vibration factor is to be considered in the analysis and in formulation of model in future study.
Banu Asfana - One of the best experts on this subject based on the ideXlab platform.
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Material Removal Rate of Zirconia in Electro Discharge Micromachining
Advanced Materials Research, 2015Co-Authors: Banu Asfana, Abdul Rahman Mohamed, Mohammad Yeakub Ali, Wayne N.p. HungAbstract:This paper investigates the material removal rate (MRR) in electro discharge micromachining (micro-EDM) of zirconia. Experimental investigation is carried out with 800 μm diameter tungsten electrode with two varying parameters rotational speed and Gap Voltage. The MRR data are analyzed and an empirical model is developed using Design Expert software. The optimum parameters for maximum MRR are found to be 375 rpm rotational speed and 80 V Gap Voltage.
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investigation of recast layer of non conductive ceramic due to micro edm
Advanced Materials Research, 2013Co-Authors: Abdul Rahman Mohamed, Banu AsfanaAbstract:This paper presents the investigation of minimum recast layer of zirconium oxide (ZrO2) due to micro-EDM using EDM-3 synthetic oil as dielectric fluid and tungsten as the tool electrode with control parameters of rotational speed and Gap Voltage. The investigation was performed using multi-process micro machine tools DT 110. The recast layer thickness was observed using scanning electron microscope and its hardness was measured using micro-Vickers hardness tester. The hardness data were analyzed and an empirical model was developed. The optimum value for minimum recast layer hardness was 873.46 Hv with rotational speed of 395 rpm and Gap Voltage of 110 V.
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Influence of Energy Parameters of Micro WEDM on Kerf
Advanced Materials Research, 2012Co-Authors: Mohammad Yeakub Ali, Willey Yun Hsien Liew, S.a. Gure, Banu AsfanaAbstract:This paper presents the estimation of kerf width in micro wire electrical discharge machining (micro WEDM) in terms of machining parameters of capacitance and Gap Voltage. An empirical model is developed by the analysis of variance (ANOVA) of experimental data. Using a wire electrode of 70 µm diameter, a minimum kerf width is found to be 92 µm for the micro WEDM parameters of 0.01 µF capacitance and 90.25 V Gap Voltage. Around 30% increament of the kerf is found to be high. The analysis also revealed that the capacitance is more influential parameter than Gap Voltage on kerf width produced by micro WEDM. As the Gap Voltage determines the breakdown distance and affects the wire vibration, the wire vibration factor is to be considered in the analysis and in formulation of model in future study.
