Showing papers on "Electrical discharge machining published in 2012"
TL;DR: In this article, the authors compared a Dimensional Analysis (DA) model, an Artificial Neural Network (ANN) model and an experimental result for a low gap current of an Electrical Discharge Machining (EDM) process.
Abstract: This paper aims to compare the material removal rate, ν between a Dimensional Analysis (DA) model, an Artificial Neural Network (ANN) model and an experimental result for a low gap current of an Electrical Discharge Machining (EDM) process. The data analysis is based on a copper electrode and steel workpiece materials. The DA and ANN model that have been developed and reported earlier by authors are used to compare the material removal of EDM process. The result indicated that the ANN model provides better accuracy towards the experimental results.
612 citations
TL;DR: In this article, the authors investigated the response of three die steel materials to surface modification by electrical discharge machining (EDM) method with tungsten powder mixed in the dielectric medium.
165 citations
TL;DR: In this article, an analytical dependence was established between the discharge energy parameters and the heat source characteristics in electrical discharge machining, and their influence on material removal rate, gap distance, surface roughness and recast layer was established.
Abstract: The machining characteristics of electrical discharge machining (EDM) directly depend on the discharge energy which is transformed into thermal energy in the discharge zone. The generated heat leads to high temperature, resulting in local melting and evaporation of workpiece material. However, the high temperature also impacts various physical and chemical properties of the tool and workpiece. This is why extensive knowledge of development and transformation of electrical energy into heat is of key importance in EDM. Based on the previous investigations, analytical dependence was established between the discharge energy parameters and the heat source characteristics in this paper. In addition, the thermal properties of the discharged energy were experimentally investigated and their influence on material removal rate, gap distance, surface roughness and recast layer was established. The experiments were conducted using copper electrode while varying discharge current and pulse duration. Analysis and experimental research conducted in this paper allow efficient selection of relevant parameters of discharge energy for the selection of most favorable EDM machining conditions.
164 citations
TL;DR: In this paper, the feasibility of machining Ti6Al4V with a bundled electrode was studied and its effect on EDM performance was compared experimentally using a solid die-sinking electrode.
Abstract: The aim of this study is to investigate an efficient Ti6Al4V electrical discharge machining (EDM) process with a bundled die-sinking electrode. The feasibility of machining Ti6Al4V with a bundled electrode was studied and its effect on EDM performance was compared experimentally using a solid die-sinking electrode. The simulation results explain the high performance of the EDM process with a bundled electrode by through the use of multi-hole inner flushing to efficiently remove molten material from the inter-electrode gap and through the improved ability to apply a higher peak current. A 3-factor, 3-level experimental design was used to study the relationships between 2 machining performance parameters (material removal rate: MRR, tool wear ratio: TWR) and 3 machining parameters (fluid flow rate, peak current and pulse duration). The main effects and influences of the 2-factor interactions of these parameters on the performances of the EDM process with the bundled electrode are discussed.
137 citations
TL;DR: In this paper, three input machining parameters including pulse current, pulse on time and open circuit voltage were changed during EDM tests to investigate the output characteristics; material removal rate (MRR), tool wear ratio (TWR), and different aspects of surface integrity for Ti-6Al-4V samples such as topography of machined surface, crack formation, white layer (recast layer) thickness and microhardness were considered as performance criteria.
Abstract: Ti–6Al–4V is a kind of difficult-to-cut material with poor machinability by traditional machining methods, while electrical discharge machining (EDM) is suitable for machining titanium alloys. In this paper, three input machining parameters including pulse current, pulse on time and open circuit voltage were changed during EDM tests. To investigate the output characteristics; material removal rate (MRR), tool wear ratio (TWR) and different aspects of surface integrity for Ti–6Al–4V samples such as topography of machined surface, crack formation, white layer (recast layer) thickness and microhardness were considered as performance criteria. The variations of MRR and TWR versus input machining parameters were investigated by means of main and interaction effect plots and also verified by ANOVA results. The effect of pulse energy based on pulse on time and pulse current variations against recast layer thickness and microhardness was studied. The possibility of forming different chemical elements and compound...
123 citations
TL;DR: In this paper, the performance of the electrical discharge machining (EDM) process is evaluated in terms of material removal rate, relative wear ratio and surface roughness of the work piece.
116 citations
01 Aug 2012
TL;DR: An attempt is made to apply six most popular population-based non-traditional optimization algorithms, i.e. genetic algorithm, particle swarm optimization, sheep flock algorithm, ant colony optimization, artificial bee colony and biogeography-based optimization for single and multi-objective optimization of two WEDM processes.
Abstract: Selection of the optimal values of different process parameters, such as pulse duration, pulse frequency, duty factor, peak current, dielectric flow rate, wire speed, wire tension, effective wire offset of wire electrical discharge machining (WEDM) process is of utmost importance for enhanced process performance The major performance measures of WEDM process generally include material removal rate, cutting width (kerf), surface roughness and dimensional shift Although different mathematical techniques, like artificial neural network, gray relational analysis, simulated annealing, desirability function, Pareto optimality approach, etc have already been applied for searching out the optimal parametric combinations of WEDM processes, but in most of the cases, sub-optimal or near-optimal solutions have been arrived at In this paper, an attempt is made to apply six most popular population-based non-traditional optimization algorithms, ie genetic algorithm, particle swarm optimization, sheep flock algorithm, ant colony optimization, artificial bee colony and biogeography-based optimization for single and multi-objective optimization of two WEDM processes The performance of these algorithms is also compared and it is observed that biogeography-based optimization algorithm outperforms the others
103 citations
TL;DR: In this paper, a study has been made to optimize the process parameters during machining of SiCp/6061 Al metal matrix composite (MMC) by wire electrical discharge machining (WEDM) using response surface methodology (RSM).
100 citations
TL;DR: Investigation of the properties of Ti-6Al-4V alloy after surface treatment by the electric discharge machining (EDM) process revealed that the samples modified by EDM provided better substrates for the adhesion, growth and viability of MG 63 cells than the TiO2 coated surface.
Abstract: This study investigated the properties of Ti–6Al–4V alloy after surface treatment by the electric discharge machining (EDM) process The EDM process with high peak currents proved to induce surface macro-roughness and to cause chemical changes to the surface Evaluations were made of the mechanical properties by means of tensile tests, and of surface roughness for different peak currents of the EDM process The EDM process with peak current of 29 A was found to induce sufficient surface roughness, and to have a low adverse effect on tensile properties The chemical changes were studied by scanning electron microscopy equipped with an energy dispersive X-ray analyser (EDX) The surface of the benchmark samples was obtained by plasma-spraying a titanium dioxide coating An investigation of the biocompatibility of the surface-treated Ti–6Al–4V samples in cultures of human osteoblast-like MG 63 cells revealed that the samples modified by EDM provided better substrates for the adhesion, growth and viability of MG 63 cells than the TiO 2 coated surface Thus, EDM treatment can be considered as a promising surface modification to orthopaedic implants, in which good integration with the surrounding bone tissue is required
99 citations
TL;DR: In this paper, the cooling effect on copper electrode while electrical discharge machining (EDM) M2 grade high speed steel workpiece was evaluated to evaluate the machinability, electrode wear ratio (EWR) and surface roughness (SR) were the two responses observed.
Abstract: This article describes a study on the cooling effect on copper electrode while electrical discharge machining (EDM) M2 grade high speed steel workpiece. To evaluate the machinability, electrode wear ratio (EWR) and surface roughness (SR) were the two responses observed. Discharge current, pulse on time, duty cycle, and gap voltage were the controllable process parameters. It was found that EWR reduced up to 20% by cryogenic cooling of electrode. With electrode cooling, SR was also found to have been reduced after machining. The effect of process parameters on EWR and SR were also analyzed. It was found that for EWR, discharge current, pulse on time, and duty cycle has the most significant effect, while pulse on time and discharge current have the most significant effect on SR. EWR and SR were found to be lower in cryogenic assisted EDM as compared to conventional EDM for the same set of process parameters. The shape of the electrode has also been measured, and it was found that the shape retention was bet...
97 citations
TL;DR: In this article, a hybrid method including response surface methodology (RSM) and back-propagation neural network (BPNN) integrated simulated annealing algorithm (SAA) were proposed to determine an optimal parameter setting.
Abstract: This study analyzes variations in metal removal rate (MRR) and quality performance of roughness average (Ra) and corner deviation (CD) depending on parameters of wire electrical discharge machining (WEDM) process in relation to the cutting of pure tungsten profiles. A hybrid method including response surface methodology (RSM) and back-propagation neural network (BPNN) integrated simulated annealing algorithm (SAA) were proposed to determine an optimal parameter setting. The results of 18 experimental runs via a Taguchi orthogonal table were utilized to train the BPNN to predict the MRR, Ra, and CD properties. Simultaneously, RSM and SAA approaches were individually applied to search for an optimal setting. In addition, analysis of variance was implemented to identify significant factors for the processing parameters. Furthermore, the field-emission scanning electron microscope images show that a lot of built-edge layers were presented on the finishing surface after the WEDM process. Finally, the optimized result of BPNN with integrated SAA was compared with that obtained by an RSM approach. Comparisons of the results of the algorithms and confirmation experiments show that both RSM and BPNN/SAA methods are effective tools for the optimization of parameters in WEDM process.
TL;DR: In this paper, two alternative technologies for roughing operations in blisk manufacture, namely, Electro Discharge Machining (EDM) and Electrochemical Machining, are presented.
TL;DR: A dual-scale structure was spontaneously formed by the nature of exfoliation characteristic of Al 7075 alloy surface during WEDM process, and it was found that Cassie state is likely to present on the secondary roughness in all fabricated surfaces.
Abstract: We present a direct one-step method to fabricate dual-scale superhydrophobic metallic surfaces using wire electrical discharge machining (WEDM). A dual-scale structure was spontaneously formed by the nature of exfoliation characteristic of Al 7075 alloy surface during WEDM process. A primary microscale sinusoidal pattern was formed via a programmed WEDM process, with the wavelength in the range of 200 to 500 μm. Notably, a secondary roughness in the form of microcraters (average roughness, Ra: 4.16 to 0.41 μm) was generated during the exfoliation process without additional chemical treatment. The low surface energy of Al 7075 alloy (γ = 30.65 mJ/m2) together with the presence of dual-scale structures appears to contribute to the observed superhydrophobicity with a static contact angle of 156° and a hysteresis less than 3°. To explain the wetting characteristics on dual-scale structures, we used a simple theoretical model. It was found that Cassie state is likely to present on the secondary roughness in al...
TL;DR: In this article, the effect of seven different process variables along with some of their interactions was evaluated using a dummy-treated experimental design and analysis of variance, and the parameter settings for rough and finish machined surface for EN31, H11, and high carbon high chromium (HCHCr) die steel materials in a powder-mixed electric discharge machining process.
Abstract: The present study was undertaken to identify the appropriate parameter settings for rough and finish machined surface for EN31, H11, and high carbon high chromium (HCHCr) die steel materials in a powder-mixed electric discharge machining process. The effect of seven different process variables along with some of their interactions was evaluated using a dummy-treated experimental design and analysis of variance. Material removal rate (MRR), tool wear rate, and surface finish were measured after each trial and analyzed. The parameter settings for rough and finished machining operations were obtained. EN31 exhibited maximum MRR as compared to the other two materials at similar process settings. Copper (Cu) electrode with aluminum suspended in the dielectric maximized the MRR. Suspending powder in the dielectric resulted in surface modification. Graphite powder showed a lower MRR but improved the surface finish. HCHCr require higher current and pulse on settings for initiating a machining cut and works best in combination with tungsten–Cu electrode and graphite powder for improved finish. The MRR for H11 is lower than EN31 but significantly higher than HCHCr under same process conditions.
TL;DR: Artificial neural network with back propagation algorithm with controlled elitist non-dominated sorting genetic algorithm has been employed in the trained network and a set of pareto-optimal solutions is obtained.
Abstract: Parametric optimization of electric discharge machining (EDM) process is a multi-objective optimization task. In general, no single combination of input parameters can provide the best cutting speed and the best surface finish simultaneously. Genetic algorithm has been proven as one of the most popular multi-objective optimization techniques for the parametric optimization of EDM process. In this work, controlled elitist non-dominated sorting genetic algorithm has been used to optimize the process. Experiments have been carried out on die-sinking EDM by taking Inconel 718 as work piece and copper as tool electrode. Artificial neural network (ANN) with back propagation algorithm has been used to model EDM process. ANN has been trained with the experimental data set. Controlled elitist non-dominated sorting genetic algorithm has been employed in the trained network and a set of pareto-optimal solutions is obtained.
TL;DR: In this article, the optimal setting of the process parameters on rotary EDM was determined through experiments planned, conducted, and analyzed using the Taguchi method, which indicated that the model has an acceptable performance to optimize the rotaryEDM process.
Abstract: Electrical discharge machining (EDM) is one of the advanced methods of machining. Most publications on the EDM process are directed towards non-rotational tools. But rotation of the tool provides a good flushing in the machining zone. In this study, the optimal setting of the process parameters on rotary EDM was determined. A total of three variables of peak current, pulse on time, and rotational speed of the tool with three types of electrode were considered as machining parameters. Then some experiments have been performed by using Taguchi's method to evaluate the effects of input parameters on material removal rate, electrode wear rate, surface roughness, and overcut. Moreover, the optimal setting of the parameters was determined through experiments planned, conducted, and analyzed using the Taguchi method. Results indicate that the model has an acceptable performance to optimize the rotary EDM process.
TL;DR: In this article, an attempt has been made to optimize the machining conditions for maximum material removal rate and maximum surface finish based on multi-objective genetic algorithm, where experiments based on Taguchi's parameter design were carried out to study the effect of various parameters, viz. pulse peak current, pulse on time, pulse off time, wire feed, wire tension and flushing pressure, on the material removal ratio and surface finish.
Abstract: The selection of optimum machining conditions, during wire electric discharge machining process, is of great concern in manufacturing industries these days. The increasing quality demands, at higher productivity levels, require the wire electric discharge machining process to be executed more efficiently. Specifically, the material removal rate needs to be maximized while controlling the surface quality. Despite extensive research on wire electric discharge machining process, determining the desirable operating conditions in industrial setting still relies on the skill of the operators and trial-and-error methods. In the present work, an attempt has been made to optimize the machining conditions for maximum material removal rate and maximum surface finish based on multi-objective genetic algorithm. Experiments, based on Taguchi’s parameter design, were carried out to study the effect of various parameters, viz. pulse peak current, pulse-on time, pulse-off time, wire feed, wire tension and flushing pressure, on the material removal rate and surface finish. It has been observed that a combination of factors for optimization of each performance measure is different. So, mathematical models were developed between machining parameters and responses like metal removal rate and surface finish by using nonlinear regression analysis. These mathematical models were then optimized by using multi-objective optimisation technique based on Non-dominated Sorting Genetic Algorithm-II to obtain a Pareto-optimal solution set.
TL;DR: In this paper, three approaches of enhancing mass transport, electrolyte flushing along the wire, wire traveling in one direction and micro-vibration of cathode wire have been studied theoretically and experimentally.
TL;DR: In this article, a bunched-electrode EDM with multi-hole inner flushing was proposed to achieve a higher material removal rate and lower tool wear ratio, while maintaining a lower level of tool wear.
Abstract: The existing applications of electrical discharge machining (EDM) for bulk material removal are restricted by their comparatively low material removal rates. The bunched-electrode EDM proposed in this study, using the powerful multi-hole inner flushing, is an effective way of being released from this restriction. This paper investigates the mechanism by which flushing (flushing modes and flushing parameters) influences machining performance indices, i.e., material removal rate and tool wear rate, using experiments and simulations. Based on an investigation conducted, compared with traditional solid electrode with mono-hole inner flushing, a bunched electrode with multi-hole inner flushing endures higher peak current and results in larger material removal rate and higher relative tool wear ratio because of a more effective flushing process. By properly choosing inlet velocity and electrode effective-area ratio, a higher material removal rate is achieved and relative tool wear ratio is kept at a lower level.
TL;DR: In this article, the impact of process parameters on tool wear and tool geometry have been analyzed with the help of scanning electron microscope (SEM) micrographs using response surface methodology (RSM).
Abstract: Inconel 718 is a nickel-based alloy designed for high yield, tensile, and creep-rupture properties. This alloy has been widely used in jet engines and high-speed airframe parts in aeronautic application. In this study, electric discharge machining (EDM) process was used for machining commercially available Inconel 718. A copper electrode with 99.9% purity having tubular cross section was employed to machine holes of 20 mm height and 12 mm diameter on Inconel 718 workpieces. Experiments were planned using response surface methodology (RSM). Effects of five major process parameters—pulse current, duty factor, sensitivity control, gap control, and flushing pressure on the process responses—material removal rate (MRR) and surface roughness (SR) have been discussed. Mathematical models for MRR and SR have been developed using analysis of variance. Influences of process parameters on tool wear and tool geometry have been presented with the help of scanning electron microscope (SEM) micrographs. Analysis shows significant interaction effect of pulse current and duty factor on MRR yielding a wide range from 14.4 to 22.6 mm3/min, while pulse current remains the most contributing factor with approximate changes in the MRR and SR of 48 and 37%, respectively, corresponding to the extreme values considered. Interactions of duty factor and flushing pressure yield a minimum surface roughness of 6.2 μm. The thickness of the sputtered layer and the crack length were found to be functions of pulse current. The hollow tool gets worn out on both the outer and the inner edges owing to spark erosion as well as abrasion due to flow of debris.
01 Jan 2012
TL;DR: In this article, the influence of three different machine rates (2, 4, 4 and 6) with constant current (6A) with WEDM of Titanium Ti-6Al-4V.
Abstract: Wire electrical discharge machining (WEDM) technology is extensively used in the field of medical, mould making, aerospace and automobile industries. Improper electrical parameters settings can affect the processing efficiency and surface roughness due to arcing phenomenon that lead by discharge point of focus. Objective of the paper is to uncover the influence of three different machine rates which are 2 mm/min, 4 mm/min and 6 mm/min with constant current (6A) with WEDM of Titanium Ti-6Al-4 V. The effects of different process parameters on the kerf width, material removal rate, surface roughness and surface topography are also discussed. The best combination of machining parameter viz. machine feed rate (4 mm/min), wire speed (8 m/min), wire tension (1.4 kg) and voltage (60 V) were identified. The paper highlights the importance of process parameters and different machining conditions on kerf width, MRR, surface roughness (Ra) and surface topography.
TL;DR: In this paper, the authors presented a numerical model and experimental validation of the anode crater formation in electrical discharge machining (EDM) process, based on the theory that the material removal process in EDM is composed of two consecutive phases: the plasma heating phase in which intensive thermal energy density is applied locally to melt the work-material and the bubble collapsing phase, in which the fluidic impact expels the molten material.
Abstract: This research presents a numerical model and the experimental validation of the anode crater formation in electrical discharge machining (EDM) process. The modeling is based on the theory that the material removal process in EDM is composed of two consecutive phases: the plasma heating phase in which intensive thermal energy density is applied locally to melt the work-material and the bubble collapsing phase in which the fluidic impact expels the molten material. A mathematical heat source model with Gaussian distributed heat flux and time variant heating area is applied in the plasma heating phase. Standard modules of a commercial computational fluid dynamics software, FLUENT, are adapted to model the crater formation in EDM. The material melting is simulated using transient heat transfer analysis and an enthalpy balance method. The volume of fraction (VOF) method is used to tackle the multiphase interactions in the processes of bubble compression and collapsing and molten material splashing and resolidification. Crater and debris geometries are attained from the model simulation and validation experiments are conducted to compare the crater morphology. The simulation and experiment results at different discharge conditions show good agreement on crater diameter suggest that the model is able to describe the mechanism of EDM crater formation. [DOI: 10.1115/1.4005303]
TL;DR: In this article, the effect of independent variables on the machining performance was analyzed in terms of material removal rate (MRR) and surface roughness (SR) on a powder mixed electro-discharge machining (EDM) process.
Abstract: Powder mixed electro-discharge machining (EDM) is being widely used in modern metal working industry for producing complex cavities in dies and moulds which are otherwise difficult to create by conventional machining route. It has been experimentally demonstrated that the presence of suspended particle in dielectric fluid significantly increases the surface finish and machining efficiency of EDM process. Concentration of powder (silicon) in the dielectric fluid, pulse on time, duty cycle, and peak current are taken as independent variables on which the machining performance was analysed in terms of material removal rate (MRR) and surface roughness (SR). Experiments have been conducted on an EZNC fuzzy logic Die Sinking EDM machine manufactured by Electronica Machine Tools Ltd. India. A copper electrode having diameter of 25 mm is used to cut EN 31 steel for one hour in each trial. Response surface methodology (RSM) is adopted to study the effect of independent variables on responses and develop predictive models. It is desired to obtain optimal parameter setting that aims at decreasing surface roughness along with larger material removal rate. Since the responses are conflicting in nature, it is difficult to obtain a single combination of cutting parameters satisfying both the objectives in any one solution. Therefore, it is essential to explore the optimization landscape to generate the set of dominant solutions. Non-sorted genetic algorithm (NSGA) has been adopted to optimize the responses such that a set of mutually dominant solutions are found over a wide range of machining parameters.
TL;DR: In this article, the effect of adding CNT powders to the dielectric on the surface integrity and the machining efficiency of the workpiece were investigated. And the average surface roughness of 0.09 μm was achieved within 1.2 h, and the material defects of the recast layer and micro-cracks were considerably reduced.
Abstract: Carbon nanotubes (CNTs) have a small specific gravity and a straight-pin shape, which allow them to continuously float and to uniformly disperse throughout the entire dielectric-filled cavity with little agglomeration during electrical discharge machining (EDM). In the past, powder mixtures of silicon, aluminum, and chrome have been used in the EDM process. However, there are concerns about flushing the controlled gap between the electrode and the workpiece because of their heavy specific gravity and their associated non-uniform dispersion in the dielectric. In this study, the effect of adding CNT powders to the dielectric on the surface integrity and the machining efficiency of the workpiece were investigated. CNTs can avoid the agglomeration problem. The CNTs were fabricated by chemical vapor deposition and added to the dielectric at a concentration of 0.4 g/l. The average surface roughness of 0.09 μm was achieved within 1.2 h, and the material defects of the recast layer and the micro-cracks were considerably reduced. The adopted processing parameters were a negative electrode polarity, a discharge current of 1 A, a pulse duration of 2 μs, an open-circuit voltage of 280 V, and gap voltage of 70 V. This technology improved the surface finish by 70% and the machining time by 66%. The achievement is attributed to the nanoscale characteristics of the CNTs in the dielectrics. The surface force became large and was able to balance the gravity body force of the CNTs. Consequently, the electric arcs were well dispersed and more uniform across the electrode gap, thus significantly enhancing the performance of the electrical discharge. It is expected that carbon nanotubes will be used in many EDM applications.
TL;DR: Abrasive powder-mixed electrical discharge machining (APM-EDM), a hybrid manufacturing process involving the use of a dielectric fluid mixed with abrasive powder, combines the benefits of mechanical and thermal interactions.
Abstract: Abrasive powder-mixed electrical discharge machining (APM-EDM), a hybrid manufacturing process involving the use of a dielectric fluid mixed with abrasive powder, combines the benefits of mechanical and thermal interactions. The aim of this article is to use a new approach of performance evaluation, gray relational analysis (GRA), to evaluate the effectiveness of optimizing multiple performance characteristics of APM-EDM of 6061Al/Al2O3p/20p aluminum matrix composites (AMCs). The considered process parameter includes the seven control factors namely pulse current (A), pulse ON time (μs), duty cycle (%), gap voltage (V), time interval of tool lift (s), abrasive powder concentration (g/L), abrasive particle size (μm), and a noise factor, aspect ratio (shape of tool electrode). The combination of L18 (21 × 37) orthogonal array design of experiment with GRA enables to determine the optimal parameters for multiple responses. GRA is used to obtain a single performance index, gray relational grade through gray relational coefficient to optimize the APM-EDM process with lower tool wear rate, surface roughness, and higher material removal rate. In addition, analysis of variance (ANOVA) for the GRC is also utilized.
TL;DR: In this paper, grey relational analysis (GRA) coupled with entropy measurement method has been employed to optimize the four machining characteristics simultaneously, grey relational grade has been computed as a performance index for predicting the optimal parameters setting for multi-machining characteristics.
Abstract: Wire electrical discharge machining (WEDM) is a well known process for generating intricate and complex geometries in hard metal alloys and metal matrix composites with high precision. In present work, intricate machining of WC-5.3%Co composite on WEDM has been reported. Taguchi’s design of experiment has been utilised to investigate the process parameters for four machining characteristics namely material removal rate, surface roughness, angular error and radial overcut. In order to optimize the four machining characteristics simultaneously, grey relational analysis (GRA) coupled with entropy measurement method has been employed. Through GRA, grey relational grade has been computed as a performance index for predicting the optimal parameters setting for multi machining characteristics. Using Analysis of Variance (ANOVA) on grey relational grade, significant parameters affecting the multi-machining characteristics has been determined. Confirmatory results prove the potential of present approach.
TL;DR: In this article, the effects of tool rotation and various intensities of external magnetic field on electrical discharge machining (EDM) performance have been studied and two mathematical models were developed to predict the material removal rate (MRR) and surface roughness (SR).
TL;DR: In this article, the effect of input parameters viz. polarity, type of electrode, peak current, pulse on time, duty cycle, gap voltage, retract distance, and concentration of fine graphite powder on machining efficiency is evaluated in terms of tool wear rate and wear ratio.
Abstract: The present experimental investigations have been carried to evaluate machining efficiency with additive powder mixed in dielectric fluid of electrical discharge machining on Inconel 718 with copper and cryogenically treated copper electrodes. Experiments have been conducted to study the effect of input parameters viz. polarity, type of electrode, peak current, pulse on time, duty cycle, gap voltage, retract distance, and concentration of fine graphite powder on machining efficiency. Machining efficiency is evaluated in terms of tool wear rate (TWR) and wear ratio (WR). The optimum factor/level combination of process parameters has been determined by Taguchi's approach treating performance measure as single objective response. Analysis of variance (ANOVA) is employed to indicate the level of significance of machining parameters for TWR and WR. The recommended optimal process input conditions have been verified by conducting confirmation experiments and significant improvement in TWR and WR is observed.
TL;DR: In this paper, application of techniques for order preference by similarity to ideal solution (TOPSIS) method is applied for solving multiple criteria (objective) optimization problem in wire electrical discharge machining (WEDM) process.
Abstract: In this paper, application of techniques for order preference by similarity to ideal solution (TOPSIS) method is applied for solving multiple criteria (objective) optimization problem in wire electrical discharge machining (WEDM) process. Three examples are included to illustrate the approach. In all the cases, it is found that, the results obtained using the TOPSIS method almost match with those derived by the past researchers which prove the applicability of this method while solving various complex decision-making problems in present day manufacturing environment.
TL;DR: In this article, the effect of process parameters and mechanism of material deposition in powder mixed electric discharge machining (PMEDM) on surface properties of EN31, H11, and High Carbon High Chromium (HCHCr) die steel materials was investigated.
Abstract: The present article investigates the effect of process parameters and mechanism of material deposition in powder mixed electric discharge machining (PMEDM) on surface properties of EN31, H11, and High Carbon High Chromium (HCHCr) die steel materials. Current, powder, and interaction between workpiece and electrode affected the microhardness significantly. Copper electrode was found best for EN31 and H11 die steel, whereas tungsten-copper electrode was better suited for HCHCr steel to achieve higher microhardness. Graphite powder was found to be more suitable compared to aluminum in improving the microhardness of all three materials. Selected samples were analyzed for X-ray diffraction (XRD) followed by microstructure analysis using a scanning electron microscope (SEM). The results showed significant material transfer from the electrode as well as powder, either in free form and/or in compound form. For maximizing the microhardness of the machined surface, optimum parametric settings were identified for th...