Journal articles: 'Electro discharge machining-Sinking'

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Ali, Mohammad Yeakub, Md Abdul Maleque, Asfana Banu, Abdus Sabur, and Sujan Debnath. "Micro Electro Discharge Machining of Non-Conductive Ceramic." Materials Science Forum 911 (January 2018): 20–27. http://dx.doi.org/10.4028/www.scientific.net/msf.911.20.

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Electro discharge machining (EDM) as a die sinking process has taken off in 1943. Since then it was known as a non-conventional machining process and its application was limited for processing only electrically conductive materials. Later on, due to the widespread applications, this EDM process is considered conventional as usual. However, in the recent years EDM has gone through considerable changes especially with dielectric fluids, simple to complex geometry, meso to micro sized structures, nanometric surface finish, and so on. In addition, the application of EDM has also been extended for processing electrically semi-conductive and non-conductive materials like ceramics and composites. This paper discussed micro electro discharge machining of non-conductive ceramic materials. It includes detail process development, modelling of material removal rate and surface finish which include the effect of multi spark and random spalling conditions.

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Marashi, Houriyeh, Ahmed A. D. Sarhan, Ibrahem Maher, and Mohd Hamdi. "Performance of Electrical Discharge Milling and Sinking in Micro Graphite Powder Mixed Dielectric." Materials Science Forum 900 (July 2017): 127–30. http://dx.doi.org/10.4028/www.scientific.net/msf.900.127.

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Electrical discharge machining (EDM) is a non-conventional machining technique that is well-known for use in fabricating dies and molds owing to machinability of high hardness materials. Although the electro-thermal mechanism of EDM offers many advantages over other available machining methods, its sluggish nature limits the wide application of such machines for mass production. In this research, adding graphite powder to dielectric is proposed to improve EDM performance factors. Material removal rate (MRR) and average surface roughness (Ra) have been monitored and evaluated after addition of graphite powder to dielectric in electrical discharge milling and sinking. It is found that the presence of powder particles in dielectric fluid enhances the MRR steadily up to ~11 and ~17% for milling and sinking process, respectively. Moreover, the highest enhancement if Ra is ~31% at 1g/l graphite powder concentration for electrical discharge milling and up to ~11% for sinking process. Field emission scanning electron microscopy (FESEM) is used to inspect the machined surfaces. The surfaces machined with graphite powder mixed appear significantly unlike the surfaces machined in pure dielectric. Adding powder to dielectric is found to increase the machined surface hardness by ~26%, from 240 to 302 HV.

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Chandrasekaran, Vasudevan, D. Kanagarajan, and R. Karthikeyan. "Electro Discharge Machining of WC/Ni Mixed Ceramic." Applied Mechanics and Materials 813-814 (November 2015): 309–16. http://dx.doi.org/10.4028/www.scientific.net/amm.813-814.309.

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Proper selection of manufacturing conditions is one of the most important aspects in the die sinking Electrical Discharge Machining (EDM) process, as these conditions determine important characteristics such as Material Removal Rate and Surface Roughness.In this work, mathematical models have been developed for relating the Material Removal Rate (MRR) and Surface Roughness (Ra), to machining parameters like tool rotational speed (S), discharge current (C), pulse-on time (T) and flushing pressure (P). The experiment plan adopts the centered central composite design unblocked (CCD). The separable influence of individual machining parameters and the interaction between these parameters are also investigated by using analysis of variance (ANOVA). This study highlights that the proposed mathematical models have proven to fit and predict values of performance characteristics close to those readings recorded experimentally with a 95% confidence interval. Results show that are the two significant factors affecting MRR (discharge current and flushing pressure). The discharge current, flushing pressure and electrode rotation have statistical significance on the Ra.

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Diéguez, Jose L., G. Araújo, E. Ares, A. Pereira, J. A. Pérez, and G. Peláez. "Computer Aided Practical Teaching of the Electro Discharge Machining Process." Materials Science Forum 625 (August 2009): 29–34. http://dx.doi.org/10.4028/www.scientific.net/msf.625.29.

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With the necessity to improve the teaching techniques of the processing technologies, in the present paper is showed the development and implantation of a application software that will serve to aid the student of the electro discharge machining process in the decision making process planning this non-conventional manufacture method. This application software manages the totality of the electro discharge machining process, in the die sinking case, by means of the creation of a data base with the necessary parameters of machining. To do these specific tasks, this application makes the data acquisition in analytical form of the machining values that the student tries to reach and has also a graphical environment form to define the geometry of the wished cavity. Finally it exposes the results in a didactic form expressed in a sheet of manufacture operations..

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Iwai, Manabu, Shinichi Ninomiya, Tokiteru Ueda, and Kiyoshi Suzuki. "Electrical Discharge Truing of a Vitrified Bonded Superabrasive Wheel with Electrical Conductivity." Advanced Materials Research 591-593 (November 2012): 319–24. http://dx.doi.org/10.4028/www.scientific.net/amr.591-593.319.

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With its high grit retention and easiness to true and dress, the vitrified bond is widely used as a bond material for cBN and diamond grinding wheels. By giving electrical conductivity to the vitrified bond, application of electrical discharge trueing/dressing and detection of a workpiece position by electrical contact sensing will become possible. And moreover, application of the vitrified bonded wheels to various types of electro-assisted grinding processes (electrochemical or electro discharge assisted methods) is expected. In this study, vitrified bonded diamond segments with electrical conductivity were manufactured experimentally by mixing the fine copper powders in the vitrified bond matrix. As a result of investigation into the electro discharge trueing performance in the die sinking and wire electro discharge machining, it was found that a vitrified bonded wheel could be formed by electro discharge machining only because the bond was electrically conductive. In addition, the electro discharge complex grinding utilizing electric discharge machining was applied to the PCD cutting tool materials using the electrically conductive vitrified bonded wheel, and confirmed that the grinding could be continued for a long time maintaining a stable grinding force.

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Mishra, Dileep Kumar, ▪. Rahul, Saurav Datta, Manoj Masanta, and Siba Sankar Mahapatra. "Through hole making by electro-discharge machining on Inconel 625 super alloy using hollow copper tool electrode." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 233, no. 2 (2018): 348–70. http://dx.doi.org/10.1177/0954408918784701.

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A case experimental research on through hole making process on Inconel 625 super alloy by using hollow (tubular) copper tool electrode in electro-discharge machining has been delineated herein. Based on three controllable process variables namely peak discharge current, pulse-on duration, and gap voltage, experiments on through hole making have been carried out following the electro-discharge machining route (die-sinking electro-discharge machining without flushing). In addition to surface morphology, topographical features of the electro-discharge machined work surface have been examined for both internal cylindrical surface of the hole produced and also the external peripheral surface of the removed cylindrical part. The influence of the process parameters have been analyzed on various process performance features like material removal rate, surface roughness, surface crack density, white layer thickness, circularity, radial overcut, and hole taper. An optimal parameter setting has been identified for sound hole making and thereby to improve electro-discharge machining performance. Additionally, energy-dispersive X-ray spectroscopic analysis has been carried out to investigate the extent of carbon enrichment onto the electro-discharge machined work surface of Inconel 625 as affected by the pyrolysis of the dielectric fluid whilst executing electro-discharge machining operation. X-ray diffraction tests have been carried out to compare metallurgy of the electro-discharge machined work surface (various phases/precipitates present in bulk of the matrix material, extent of grain refinement, crystallite size, strain, and dislocation density) with respect to that of “as received” Inconel 625. Results, thus obtained, have also been compared to that of the micro-hardness test data.

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Li, J.-B., K. Jiang, and G. J. Davies. "Novel die-sinking micro-electro discharge machining process using microelectromechanical systems technology." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 220, no. 9 (2006): 1481–87. http://dx.doi.org/10.1243/09544062jmes323ft.

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A novel die-sinking micro-electro discharge machining (EDM) process is presented for volume fabrication of metallic microcomponents. In the process, a high-precision silicon electrode is fabricated using deep reactive ion etching (DRIE) process of microelectromechanical systems (MEMS) technology and then coated with a thin layer of copper to increase the conductivity. The metalized Si electrode is used in the EDM process to manufacture metallic microcomponents by imprinting the electrode onto a flat metallic surface. The two main advantages of this process are that it enables the fabrication of metallic microdevices and reduces manufacturing cost and time. The development of the new EDM process is described. A silicon component was produced using the Surface Technology Systems plasma etcher and the DRIE process. Such components can be manufactured with a precision in nanometres. The minimum feature of the component is 50 μm. In the experiments, the Si component was coated with copper and then used as the electrode on an EDM machine of 1 μm resolution. In the manufacturing process, 130 V and 0.2 A currents were used for a period of 5 min. The SEM images of the resulting device show clear etched areas, and the electric discharge wave chart indicates a good fabrication condition. The experimental results have been analysed and the new micro-EDM process is found to be able to fabricate 25 μm features.

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Mascaraque-Ramírez, Carlos, and Patricio Franco. "Comparison between different methods for experimental analysis of surface integrity in die-sinking electro-discharge machining processes." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 234, no. 3 (2019): 479–88. http://dx.doi.org/10.1177/0954405419876471.

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Advanced manufacturing techniques such as die-sinking electro-discharge machining have been introduced in different industries such as the naval, automotive and product manufacturing. The surface finish of the parts subjected to these processes is influenced by diverse factors related to geometrical parameters, electric circuit, lubrication system and materials. For that reason, this work is focused on the analysis of the surface morphology of machined part that can be achieved by electro-discharge machining, as a function of some of the main process parameters such as the current intensity and penetration depth. In this work, three different methods for experimental analysis of surface quality, based on the measuring of surface roughness, material profile ratio and crater diameter, were applied and compared. The experimental phase included tests with copper tools on AISI 316 stainless steel workpieces. The surface roughness and accumulated material profile were recorded using measurements made with a profilometer, and for the purpose of measuring the diameter of the craters, scanning electron microscopy technology was used. According to the results, crater diameter can be adopted as a better indicator to characterize the surface quality in electro-discharge machining, because it exhibits a clearer tendency as a function of current intensity and penetration depth.

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Asmelash, Mebrahitom, and Muhamad Azhari. "Examination of Machining Parameters on the Surface Roughness of Stavax ESR Material Using Electro Discharge Machining." Advanced Materials Research 1133 (January 2016): 339–43. http://dx.doi.org/10.4028/www.scientific.net/amr.1133.339.

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An experimental study was conducted to investigate the effect of EDM die sinking machining parameters on surface roughness of Stavax material for mould insert. The spark gap, peak current and servo voltage were manipulated to find the best combination of EDM machining parameters. The surface roughness of the machined surface of each specimen was measured using Perthometer and the image of texture was observed by using optical microscope. It was observed that the surface roughness was highly affected by the spark gap and peak current whereas the servo voltage had little effect.

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Rajeswari, R., and M. S. Shunmugam. "Comparison of Conventional, Powder Mixed, and Ultrasonic Assisted EDM by Phenomenological Reasoning." International Journal of Materials Forming and Machining Processes 5, no. 2 (2018): 32–44. http://dx.doi.org/10.4018/ijmfmp.2018070103.

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Electro-discharge machining (EDM) is widely used in industries for machining complex shapes and difficult-to-machine materials that are conductive. In the present work, performance of conventional die-sinking EDM process is compared with powder mixed and ultrasonic assisted processes in machining of D3 steel. Using different sets of parameters for rough and finish ED machining, material removal rate and surface roughness are obtained experimentally. The influences of the parameters on material removal rate and surface roughness are presented on the basis of phenomenological reasoning. The results are discussed and suitable recommendations for the practitioners are included.

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Sabyrov, Nurbol, M. Jahan, Azat Bilal, and Asma Perveen. "Ultrasonic Vibration Assisted Electro-Discharge Machining (EDM)—An Overview." Materials 12, no. 3 (2019): 522. http://dx.doi.org/10.3390/ma12030522.

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Many of the industrial processes, including material removal operation for shape generation on the surface of material, exploit the assistance of ultrasonic vibrations. This trend of using ultrasonic vibration in order to improve the process performance is becoming more and more prominent recently. One of the significant applications of this ultrasonic vibration is in the industrial processes such as Electro-discharge machining (EDM), where ultrasonic vibration (UV) is inserted as a medium for enhancing the process performance. Mostly ultrasonic vibration is applied along with the EDM process to increase the efficiency of the process through debris cleansing from the sparking gap. There have been significant changes in ultrasonic assisted technology during the past years. Due to its inherent advantages, ultrasonic assistance infiltrated in different areas of EDM, such as wire cut EDM, micro EDM and die sinking EDM. This article presents an overview of ultrasonic vibration applications in electric discharge machining. This review provides information about modes of UV application, impacts on parameters of performance, optimization and process designing on difficult-to-cut materials. On the bases of available research works on ultrasonic vibration assisted EDM, current challenges and future research direction to improve the process capabilities are identified. Literature suggested improved material removal rate (MRR), increased surface roughness (SR) and tool wear ratio (TWR) due to the application of ultrasonic vibration assisted EDM. However, tool wear and surface roughness can be lessened with the addition of carbon nanofiber along with ultrasonic vibration. Moreover, the application of ultrasonic vibration to both tool and workpiece results in higher MRR compared to its application to single electrode.

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ZHANG, Yanzhen. "Research on the Rheology of Water-in-oil Emulsion Used in Sinking Electro-discharge Machining." Journal of Mechanical Engineering 47, no. 05 (2011): 188. http://dx.doi.org/10.3901/jme.2011.05.188.

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Kruth, J. P., L. Stevens, L. Froyen, and B. Lauwers. "Study of the White Layer of a Surface Machined by Die-Sinking Electro-Discharge Machining." CIRP Annals 44, no. 1 (1995): 169–72. http://dx.doi.org/10.1016/s0007-8506(07)62299-9.

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Gatzen, H. H., Fritz Klocke, Susanne Kamenzky, and Ornwasa Traisigkhachol. "Electroplated Cu Micro Electrode for the Application in Micro Sinking Electro Discharge Machining (Micro-SEDM)." ECS Transactions 16, no. 45 (2019): 255–68. http://dx.doi.org/10.1149/1.3140027.

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Assarzadeh, Saeed, and Majid Ghoreishi. "Electro-thermal-based finite element simulation and experimental validation of material removal in static gap single-spark die-sinking electro-discharge machining process." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 231, no. 1 (2016): 28–47. http://dx.doi.org/10.1177/0954405415572661.

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Existing single spark models are subjected to too simplistic assumptions such as uniform or point heat source, constant plasma radius, invariable materials properties and constant surface temperature during discharge making them far from reality. In this study, more realistic assumptions including Gaussian type distribution of spark heat flux, temperature dependent materials properties, latent heat of melting and expanding plasma channel with pulse current and time have been made to establish a comprehensive modeling platform. The ABAQUS FEM software has been used to simulate the mechanism of crater formation due to a single discharge. The non-uniform thermal flux was programmed through the DFLUX subroutine. The simulation results show that the temperature of work piece decreases as the discharge time increases while the volume of melted and evaporated material increases. A specially designed single spark experimental set-up was developed in laboratory to carry out a few single spark tests for verification purposes. The obtained craters morphologies were examined by optical microscopy and scanning profilometer. It has been shown that the present approach outperforms other previously developed thermal models with respect to cavity outline and size possessing the maximum confirmation errors of 18.1% and 14.1% in predicting crater radius and depth, respectively. Parametric analysis reveals that the melting boundary moves onward by increasing discharge current, whereas it moves back prolonging discharge time. Finally, a closer proximity to experimental material removal rates than those predicted by analytical approach has been recognized which confirms its more precise generalization capabilities towards the real state EDM process.

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Ojha, Nirdesh, Claas Müller та Holger Reinecke. "Parametric Analysis of μ-Electric Discharge Machining of Non-Conductive Si₃N₄". Applied Mechanics and Materials 564 (червень 2014): 560–65. http://dx.doi.org/10.4028/www.scientific.net/amm.564.560.

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Electric discharge machining (EDM) is an electro-thermal non-traditional machining process used to machine conductive materials. EDM process can be used to machine non-conductive ceramics by applying an assisting electrode (AE) on top of the insulating ceramics. The initial discharges occur between the tool electrode and the assisting electrode. During the spark erosion process an intrinsic conductive layer is continuously produced on the insulating ceramic. This transitional conductive layer ensures that the electric contact is sustained. However, result of parametric analysis of the EDM of non-conductive ceramics is not available. This paper presents a parametric study to evaluate the influence of five major EDM process parameters (peak current, open-circuit voltage, servo, pulse width and gap voltage) on two response variables (material removal rate and the tool ware rate) when structuring non-conductive Si3N4ceramics using the die-sinking μ-EDM process with the help of the AE. A set of experimental trials planned with fractional factorial design with a resolution of V was performed to evaluate the primary, two-factor and quadratic effects.

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Raj, Sumit, and Kaushik Kumar. "Optimization and Prediction of Material Removing Rate in Die Sinking Electro Discharge Machining of EN45 Steel Tool." Materials Today: Proceedings 2, no. 4-5 (2015): 2346–52. http://dx.doi.org/10.1016/j.matpr.2015.07.296.

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Chen, Xiang, Zhenlong Wang, Yukui Wang, and Guanxin Chi. "Micro sinking electro-discharge machining of complex 3D micro-cavity using in-situ milled graphite microform electrode." Journal of Materials Processing Technology 270 (August 2019): 206–15. http://dx.doi.org/10.1016/j.jmatprotec.2019.02.028.

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Porwal, Rajesh Kumar, Vinod Yadava, and J. Ramkumar. "Neural Network Based Modelling and GRA Coupled PCA Optimization of Hole Sinking Electro Discharge Micromachining." International Journal of Manufacturing, Materials, and Mechanical Engineering 4, no. 1 (2014): 1–21. http://dx.doi.org/10.4018/ijmmme.2014010101.

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Determination of material removal rate (MRR), tool wear rate (TWR) and hole taper (Ta) is a challenging task for manufacturing engineers from the productivity and accuracy point of view of the symmetrical and nonsymmetrical holes due to hole sinking electro discharge micro machining (HS-EDMM) process. Thus, mathematical models for quick prediction of these aspects are needed because experimental determinations of process performances are always tedious and time consuming. Not only prediction but determination of optimum parameter for optimization of process performance is also required. This paper attempts to apply a hybrid mathematical approach comprising of Back Propagation Neural Network (BPNN) for prediction and Grey Relational Analysis (GRA) coupled with Principal Component Analysis (PCA) for optimization with multiple responses of HS-EDMM of Invar-36. Experiments were conducted to generate dataset for training and testing of the network where input parameters consist of gap voltage, capacitance of capacitor and the resulting performance parameters MRR, TWR and Ta. The results indicate that the hybrid approach is capable to predict process output and optimize process performance with reasonable accuracy under varied operating conditions of HS-EDMM. The proposed approach would be extendable to other configurations of EDMM processes for different material.

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Alamro, Turki, Mohammed Yunus, Rami Alfattani, and Ibrahim A. Alnaser. "Effect of a Rapid Tooling Technique in a 3D Printed Part for Developing an EDM Electrode." International Journal of Polymer Science 2021 (March 29, 2021): 1–12. http://dx.doi.org/10.1155/2021/6616652.

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The role of rapid tooling (RT) in additive manufacturing (AM) seems essential in improving and spreading out the vista of manufacturing proficiency. In this article, attempts were made to discover the feasibility and the accomplishments of the RT electrode in the field of electro-discharge machining (EDM). Fused deposition modeling (FDM) is one of the AM processes adopted to fabricate the EDM electrode prototype by coating with copper. The copper is deposited on FDM-built ABS plastic component for about 1 mm through thick electroplating. The copper-coated FDM (CCF) and solid copper (SC) electrodes are used to conduct experiments on a die-sinking EDM machine using tool alloy steel as a workpiece. The CCF polymer electrode can be efficiently used in EDM operations as the build time of any complex shape was substantially reduced. However, the material removal rate (MRR) is far less than that of the SC electrode. It is recommended that the CCF electrode is used for semifinishing and finishing operations in which MRR happens to be less. However, CCF can get spoiled as high temperatures are generated on the machining tool, and the plastic core hardly sustains such high temperatures.

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Shather, Saad K., Sami A. Hammood, Noor Al-Huda A. Hussain, and Noor H. Hasson. "surface roughness,metal removal Effect of Wire Diameter, Feeding Rate, Pulse (on/off) Time on Surface Roughness and Metal Removal Rate for Cr-Mo Steel (SCM425H) During Wire Electrical Discharge Machine (WEDM) Cutting Operation." Engineering and Technology Journal 38, no. 6A (2020): 854–60. http://dx.doi.org/10.30684/etj.v38i6a.524.

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Increase the demand to produce complex shapes with high quality and dimensional accuracy such as production aerospace, cars, die sinking has been leading to increase the demand to use the non- traditional cutting operations such as wire electro-discharge machine (WEDM) rather than using the traditional operations. An idea to understand the effect of wire diameter, wire feed, pulsing (on/off) time on surface roughness, and metal removal rate of Cr-Mo steel during wire electrical discharge machining was investigated. Two Steel alloy samples with dimensions of (60 x50 x 20)mm were cut into four rectangular spaces with (5x10x20)mm at one side of each sample using wire cut (EDM) machine with a wire diameter of 0.25 mm and feeding rate 2 m/min for sample 1 and a 0.3 mm diameter and 3 m/min feeding rate for sample 2. Pulse (on, off) time was (110, 50), (112, 52), (115, 55), (116, 57) corresponds to space 1, space 2, space 3, and space 4 in both steel block. Surface roughness and metal removal rate measurements were estimated. The results showed that wire diameter, feeding rate, and pulse (on, off) time is proportional with metal removal rate, while reversed with surface roughness. The wire diameter of 0.3 mm and a feeding rate of 3m/min enhanced better surface quality and productivity. Pulse (on, off) time is the most effective parameter. Best duration time was recorded at the values (116, 57).

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Kumar, S., R. Singh, T. P. Singh, and B. L. Sethi. "Comparison of material transfer in electrical discharge machining of AISI H13 die steel." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 223, no. 7 (2009): 1733–40. http://dx.doi.org/10.1243/09544062jmes1227.

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The electrical discharge machining (EDM) process is extensively used in the tool and die making industry for accurate machining of internal profiles in hardened materials. Although it is essentially a material removal process, efforts have been made in the recent past to use it as surface treatment method. This article investigates and compares the effect of material transfer from electrode bodies (copper, copper—chromium, and copper—tungsten) and tungsten powder suspended in the dielectric medium during die-sinking EDM of AISI H13 die steel. Results show a 76 per cent increase in micro-hardness by machining with a copper—tungsten electrode and a 111 per cent increase by machining with tungsten powder mixed in the dielectric. The copper—chromium electrode gives the best surface roughness (Ra) value of 2.67 μ m. Scanning electron microscopy and X-ray diffraction analysis of the machined surfaces show alloying of parent material with tungsten and tungsten carbide. Chemical composition of the machined surfaces was further checked on an optical emission spectrometer to verify the results. Besides a significant presence of tungsten, an increase in the percentage of carbon is also observed.

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Pradana, Yanuar Rohmat Aji, Aldi Ferara, Aminnudin Aminnudin, Wahono Wahono, and Jason Shian-Ching Jang. "The Effect of Discharge Current and Pulse-On Time on Biocompatible Zr-based BMG Sinking-EDM." Open Engineering 10, no. 1 (2020): 401–7. http://dx.doi.org/10.1515/eng-2020-0049.

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AbstractThe machinability information of Zr-based bulk metallic glasses (BMGs) are recently limited but essential to provide technological recommendation for the fabrication of the medical devices due to the material’s metastable nature. This study aims to investigate the material removal rate (MRR) and surface roughness under different current and pulse-on time of newly developed Ni- and Cu-free Zr-based BMG using sinking-electrical discharge machining (EDM). By using weightloss calculation, surface roughness test and scanning electron microscopy (SEM) observation on the workpiece after machining, both MRR and surface roughness were obtained to be increased up to 0.594 mm3/min and 5.50 μm, respectively, when the higher current was applied. On the other hand, the longer pulse-on time shifted the Ra into the higher value but lower the MRR value to only 0.183 mm3/min at 150 μs. Contrary, the surface hardness value was enhanced by both higher current and pulse-on time applied during machining indicating different level of structural change after high-temperature spark exposure on the BMG surface. These phenomena are strongly related to the surface evaporation which characterize the formation of crater and recast layer in various thicknesses and morphologies as well as the crystallization under the different discharge energy and exposure time.

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Singh, Param, Vinod Yadava, and Audhesh Narayan. "Machining Performance Characteristics of Inconel 718 Superalloy Due to Hole-Sinking Ultrasonic Assisted Micro-EDM." Journal of Advanced Manufacturing Systems 17, no. 01 (2018): 89–105. http://dx.doi.org/10.1142/s0219686718500063.

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Inconel 718 superalloy is widely used in aerospace industries for fabrication of the various components for aircraft engine because of its high strength at elevated temperature. It is an extremely difficult-to-machine material due to its work hardening nature and poor thermal conductivity. Creating micro-holes of high precision in this material is beyond the capability of conventional twist drill due to its low thermal conductivity. Micro-electrical discharge machining (micro-EDM) is a well-established process for the machining of any electrically conductive hard and brittle material, but due to very small feature size and narrow discharge gap, removal of debris becomes difficult, causes arcing and short-circuiting. In order to solve this problem, authors indigenously developed an innovative ultrasonic-assisted micro-EDM setup for workpiece vibration. The machining performance characteristics of Inconel 718 superalloy was studied using the developed setup in sinking configuration in terms of material removal rate (MRR), tool wear rate (TWR) and hole taper ([Formula: see text]) considering the effect of ultrasonic power, gap current, pulse on time and pulse off time. It was observed that higher ultrasonic power was more suitable for higher MRR, lower TWR and [Formula: see text]. It was also found from the results that 3 A gap current at 6[Formula: see text][Formula: see text]s pulse on time was appropriate for better MRR and 12[Formula: see text][Formula: see text]s pulse on time was more appropriate for low TWR and [Formula: see text]. The scanning electron microscope (SEM) analysis of created micro-holes was also performed with and without ultrasonic vibration to ensure the quality as well as accuracy.

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PONAPPA, K., K. S. K. SASIKUMAR, M. SAMBATHKUMAR, and M. UDHAYAKUMAR. "MULTI-OBJECTIVE OPTIMIZATION OF EDM PROCESS PARAMETERS FOR MACHINING OF HYBRID ALUMINUM METAL MATRIX COMPOSITES (Al7075/TiC/B4C) USING GENETIC ALGORITHM." Surface Review and Letters 26, no. 10 (2019): 1950071. http://dx.doi.org/10.1142/s0218625x19500719.

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This study deals with the investigation on the effect of Electrical Discharge Machining (EDM) parameters during machining of hybrid composite (Al 7075/TiC/B4C). The optimum process parameters of die sinking EDM like pulse current, pulse duration and gap voltage on metal removal rate, tool wear rate and surface finish were investigated. Full factorial experimental design was selected for experiments. Analysis of variance was employed to study the influence of process parameters and their interactions on response variables. Among the process parameters considered, it was observed that the pulse current was found to be more influential in affecting MRR, TWR and SR. The other parameters have little effect on the response variable. Multi-objective optimization study was also performed using genetic algorithm to find the optimum parameter setting for controversial objective function combination such as high MRR and low SR and High MRR and low TWR. Scanning electron microscope study was performed to study the surface characteristics.

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Jahan, Muhammad Pervej, Mustafizur Rahman, and Yoke San Wong. "Migration of Materials during Finishing Micro-EDM of Tungsten Carbide." Key Engineering Materials 443 (June 2010): 681–86. http://dx.doi.org/10.4028/www.scientific.net/kem.443.681.

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Present study aims to investigate the migration of materials onto the surface of workpiece and electrode during fine-finish die-sinking and milling micro-EDM of tungsten carbide using pure tungsten electrode. The effect of materials transfer on the machined surface characteristics is also presented. The machined surfaces have been examined under scanning electron microscope (SEM) and energy dispersive X-ray (EDX) in order to investigate the changes in chemical composition due to the migration of materials. It has been observed that materials from both workpiece and electrode transfer to each other depending on machining conditions and discharge energy. A significant amount of carbon migrates to both electrode and workpiece surface due to the decomposition of dielectric hydrocarbon during breakdown. The migration occurs more frequently at lower gap voltages during finish die-sinking micro-EDM due to low spark gap and stationary tool electrode. Milling micro-EDM suffers from lower amount of carbon migration and fewer surface defects which improve the overall surface finish and reduce surface roughness significantly.

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Rodriguez, Gloria P., Jorge Simao, and Gemma Herranz. "Surface Alloying of AISI H13 Steel during Electrical Discharge Machining (EDM)." Defect and Diffusion Forum 289-292 (April 2009): 119–26. http://dx.doi.org/10.4028/www.scientific.net/ddf.289-292.119.

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Electrical discharge machining (EDM) is one of the most widely used non-conventional machining processes for the production of moulds/dies, cutting tools and aero-engine parts, such as turbine/compressor blades. The paper details experimental research on the surface alloying/modification of chromium martensitic hot-work tool steel components (AISI H13, 55HRC) during EDM die-sinking operations using powder metallurgy (PM) tool electrodes, as a means of achieving enhanced workpiece wear resistance without resorting to a subsequent coating operation. Tool electrode performance of partially sintered WC/Co electrodes operating in a common hydrocarbon oil dielectric was assessed and subsequently compared with that of conventional electrode materials, such as Cu and Graphite. Surface/subsurface observations by optical and scanning electron microscopy (SEM) showed a recast solidified layer of ~ 8 µm when using WC/Co electrodes. Performed XRD and SEM-EDX analysis indicated that WC and Co contained in the PM tool electrodes, together with C decomposed from the hydrocarbon oil during sparking, were transferred and alloyed to the steel substrate surfaces. EDM surface alloyed layers were hardened over 1200 HK0.025. This hardening is related both to the formation of tungsten carbides with different stoichiometries and to the non-equilibrium microstructure evolution. Thickness of the hardened zone was shown to be dependent on EDM operating parameters, in particular peak-current (A) and pulse on-time (s).

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Mouralova, Katerina, Libor Benes, Josef Bednar, Radim Zahradnicek, Tomas Prokes, and Jiří Fries. "Analysis of Machinability and Crack Occurrence of Steels 1.2363 and 1.2343ESR Machined by Die-Sinking EDM." Coatings 10, no. 4 (2020): 406. http://dx.doi.org/10.3390/coatings10040406.

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Die-sinking electric discharge machining (EDM) is an indispensable technological operation, especially in the production of molds and all internal and external shapes and cavities. For this reason, the effect of machine parameter settings (open-voltage, pulse current, pulse on time, and pulse off time) on the machining of two types of steels, 1.2363 and 1.2343ESR, was carefully investigated using graphite or copper electrodes in 10 mm × 10 mm or 100 mm × 100 mm shapes. For this purpose, a two-level half factor experiment was performed with one replication at the corner points and two replications at the central points, with a total of 80 rounds. The subject of the evaluation was the topography and morphology of machined surfaces including a detailed analysis of surface and subsurface defects in the form of cracks including the creation of regression equations describing the probability of crack occurrence. Furthermore, a study of the local hardness change in the subsurface area was performed, and lamellas were also made and studied by transmission electron microscopy. It has been found that by using die-sinking EDM, it is possible to effectively predict the probability of cracking on machined surfaces and also on machine 1.2363 and 1.2343ESR steels with a very good surface quality of Ra 1.9 and 2.1 µm using graphite electrodes. These findings will ensure the production of parts with the required surface quality without cracks, which is a crucial aspect for maintaining the required functionality and service life of the parts.

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Sultan, Teepu, Anish Kumar, and Rahul Dev Gupta. "Material Removal Rate, Electrode Wear Rate, and Surface Roughness Evaluation in Die Sinking EDM with Hollow Tool through Response Surface Methodology." International Journal of Manufacturing Engineering 2014 (September 23, 2014): 1–16. http://dx.doi.org/10.1155/2014/259129.

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Electrical discharge machining is one of the earliest nontraditional machining, extensively used in industry for processing of parts having unusual profiles with reasonable precision. In the present work, an attempt has been made to model material removal rate, electrode wear rate, and surface roughness through response surface methodology in a die sinking EDM process. The optimization was performed in two steps using one factor at a time for preliminary evaluation and a Box-Behnken design involving three variables with three levels for determination of the critical experimental conditions. Pulse on time, pulse off time, and peak current were changed during the tests, while a copper electrode having tubular cross section was employed to machine through holes on EN 353 steel alloy workpiece. The results of analysis of variance indicated that the proposed mathematical models obtained can adequately describe the performances within the limits of factors being studied. The experimental and predicted values were in a good agreement. Surface topography is revealed with the help of scanning electron microscope micrographs.

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Modica, Francesco, Vito Basile, Valeria Marrocco, and Irene Fassi. "A New Process Combining Micro-Electro-Discharge-Machining Milling and Sinking for Fast Fabrication of Microchannels With Draft Angle." Journal of Micro and Nano-Manufacturing 4, no. 2 (2016). http://dx.doi.org/10.1115/1.4032324.

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A comparison of the machining performance of micro-electro-discharge machining (EDM) milling and sinking is proposed considering the fabrication of microchannels with controlled sloped walls realized in a hardened steel workpiece. Adopting the fine-finishing machining regime for both micro-EDM techniques, the experimental results show that micro-EDM sinking is about ten times faster than milling in the worst case, though a lack of accuracy in the final microfeatures in the former case is detected due to not compensated tool wear. On the contrary, micro-EDM milling provides a better control of the microchannel dimensions. Finally, a microfilter mold for medical applications is machined in order to show the potential of the combination of both technologies.

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Jeykrishnan, J., B. Vijaya Ramnath, G. Sureshrajan, M. Siva Bharath, X. Hervin Savariraj, and S. Akilesh. "Effects of Die-Sinking Electro-Discharge Machining Parameters on Surface Roughness in Inconel 825 Alloy." Indian Journal of Science and Technology 9, no. 41 (2016). http://dx.doi.org/10.17485/ijst/2016/v9i41/103303.

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Petersen, Timm, Ugur Küpper, Tim Herrig, Andreas Klink, and Thomas Bergs. "Fracture Toughness and Tribological Properties of Cemented Carbides Machined by Sinking Electrical Discharge Machining." ESAFORM 2021, April 5, 2021. http://dx.doi.org/10.25518/esaform21.1518.

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The quality of a forming process highly depends on the pressure applied to the workpiece. Consequently, the demand for higher workpiece qualities results in a demand for tools that can withstand high compressive stresses. Moreover, the tendency of using materials like high-strength steels as workpiece material, urges the need for tool materials that can withstand high compressive stresses and are resistant to wear. A class of materials that offer a combination of hardness or wear resistance and ductility are cemented carbides. However, these properties hamper their machining with conventional cutting technologies. Due to its electro-thermal working principle, Electrical Discharge Machining (EDM) is able to machine materials independently from their mechanical properties. On the other hand, the removal process is accompanied by thermal stresses, which can cause residual stresses and micro cracks near the machined surface. Due to their pre-existing stresses from the sintering process, cemented carbides are especially susceptible for these kind of damages. It is therefore necessary to identify the impact of EDM on the material. Different machining strategies are tested with two different types of cemented carbides and examined regarding their fracture toughness. The crack surfaces resulting from the three point bending test are microscopically inspected regarding failure initiation. Additionally pin-on-disc tests are conducted to determine the influence of the EDM strategies on the tribological properties of the machined cemented carbides.

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Surleraux, Anthony, Romain Lepert, Jean-Philippe Pernot, Pierre Kerfriden, and Samuel Bigot. "Machine Learning-Based Reverse Modeling Approach for Rapid Tool Shape Optimization in Die-Sinking Micro Electro Discharge Machining." Journal of Computing and Information Science in Engineering 20, no. 3 (2020). http://dx.doi.org/10.1115/1.4045956.

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Abstract This paper focuses on efficient computational optimization algorithms for the generation of micro electro discharge machining (µEDM) tool shapes. In a previous paper, the authors presented a reliable reverse modeling approach to perform such tasks based on a crater-by-crater simulation model and an outer optimization loop. Two-dimensional results were obtained but 3D tool shapes proved difficult to generate due to the high numerical cost of the simulation strategy. In this paper, a new reduced modeling optimization framework is proposed, whereby the computational optimizer is replaced by an inexpensive surrogate that is trained by examples. More precisely, an artificial neural network (ANN) is trained using a small number of full reverse simulations and subsequently used to directly generate optimal tool shapes, given the geometry of the desired workpiece cavity. In order to train the ANN efficiently, a method of data augmentation is developed, whereby multiple features from fully simulated EDM cavities are used as separate instances. The performances of two ANN are evaluated, one trained without modification of process parameters (gap size and crater shape) and the second trained with a range of process parameter instances. It is shown that in both cases, the ANN can produce unseen tool shape geometries with less than 6% deviation compared to the full computational optimization process and at virtually no cost. Our results demonstrate that optimized tool shapes can be generated almost instantaneously, opening the door to the rapid virtual design and manufacturability assessment of µEDM die-sinking operations.

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Journal articles on the topic 'Electro discharge machining-Sinking'

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