Showing papers on "Electrical discharge machining published in 2019"
TL;DR: The proposed technology allows modification of the mechanical properties and surface characteristics according to an orthopedic implant’s requirements and reveals a higher adhesion strength, which permits to enhance the wear resistance of the Ti-64 alloy.
Abstract: In the present research, a composite layer of TiO2-TiC-NbO-NbC was coated on the Ti-64 alloy using two different methods (i.e., the electric discharge coating (EDC) and electric discharge machining processes) while the Nb powder were mixed in dielectric fluid. The effect produced on the machined surfaces by both processes was reported. The influence of Nb-concentration along with the EDC key parameters (Ip and Ton) on the coated surface integrity such as surface topography, micro-cracks, coating layer thickness, coating deposition, micro-hardness has been evaluated as well. It has been noticed that in the EDC process the high peak current and high Nb-powder concentration allow improvement in the material migration, and a crack-free thick layer (215 μm) on the workpiece surface is deposited. The presence of various oxides and carbides on the coated surface further enhanced the mechanical properties, especially, the wear resistance, corrosion resistance and bioactivity. The surface hardness of the coated layer is increased from 365 HV to 1465 HV. Furthermore, the coated layer reveals a higher adhesion strength (~118 N), which permits to enhance the wear resistance of the Ti-64 alloy. This proposed technology allows modification of the mechanical properties and surface characteristics according to an orthopedic implant’s requirements.
106 citations
TL;DR: The objective of this review is to benefit the researchers to understand the PMEDM concept precisely and study the process parameters furthermore in particulars to get enhancements in the process to achieve better quality levels.
77 citations
TL;DR: In this paper, the influence of modified tool (tool with texturing) on the process of orthogonal turning of Ti-6Al-4V work material was investigated.
Abstract: Importance of this present investigation is to identify the influence of modified tool (tool with texturing) on the process of orthogonal turning of Ti–6Al–4V work material. To achieve the enhanced...
76 citations
TL;DR: A comprehensive literature review of the conventional machining processes along with optimization methods used in metal matrix composites (MMCs) such as turning, milling, drilling, and grinding machining is presented in this article.
Abstract: This paper offers a comprehensive literature review of the conventional machining processes along with optimization methods used in metal matrix composites (MMCs), such as turning, milling, drilling, and grinding machining processes. The tool wear mechanism and machinability of MMCs along with surface quality are discussed in the number of different manufacturing processes and examined thoroughly. Additionally, the manufacturing of MMC products through nonconventional machining processes such as electrical discharge machining (EDM), wire electrical discharge machining (WEDM), laser machining, electrochemical machining, ultra- sonic machining (USM), and high-speed machining are investigated and considered, in connection with MMC processing are discussed, as alternatives to the aforementioned processes. Moreover, this review focuses on the modeling of the machining process, finite element modeling, and simulation and optimization of soft computing methods in MMCs. The study will emphasize on the most generally used methods, namely, response surface methodology, artificial neural network, Taguchi method, and fuzzy logic as soft computing optimization methods. Finally, the comprehensive open issues and conclusions have drawn on the machining and optimization of particle-reinforced MMCs.
76 citations
TL;DR: Nimonic C-263 superalloy offers a wide range of outstanding properties, namely, high-temperature resistance, high specific strength, high thermal fatigue, and hot corrosion resistance as discussed by the authors.
Abstract: Nimonic C-263 superalloy offers a wide range of outstanding properties, namely, high-temperature resistance, high specific strength, high thermal fatigue, and hot corrosion resistance. The concern ...
76 citations
TL;DR: In this article, the impact of wire electric discharge machining (WEDM) parameters on material removal rate (MRR) and surface roughness (Ra) for the newly developed Magnesium metal matrix composite was investigated.
74 citations
01 Jan 2019
TL;DR: Electrical discharge machining has emerged as one of the most accepted non-traditional machining methods that have the capability of attaining complex shapes and better feature size in difficult-to-reach environments as discussed by the authors.
Abstract: Electrical discharge machining has emerged as one of the most accepted non-traditional machining methods that have the capability of attaining complex shapes and better feature size in difficult-to...
74 citations
TL;DR: In this paper, a research endeavor was performed to analyze the influence of process parameters with normal tap water mixed deionized water as insulating medium, and the optimum combination has also been found using Taguchi Grey-relational approach to achieve better multiple response parameters in the proposed eco friendly electrical discharge machining process.
71 citations
TL;DR: The optimized parameters were found to machine the alloy appropriately with the intact shape memory effect and proved to be highly effective in predicting and optimizing the wire electrical discharge machining (WEDM) process parameters.
Abstract: Nitinol, a shape-memory alloy (SMA), is gaining popularity for use in various applications. Machining of these SMAs poses a challenge during conventional machining. Henceforth, in the current study, the wire-electric discharge process has been attempted to machine nickel-titanium (Ni55.8Ti) super-elastic SMA. Furthermore, to render the process viable for industry, a systematic approach comprising response surface methodology (RSM) and a heat-transfer search (HTS) algorithm has been strategized for optimization of process parameters. Pulse-on time, pulse-off time and current were considered as input process parameters, whereas material removal rate (MRR), surface roughness, and micro-hardness were considered as output responses. Residual plots were generated to check the robustness of analysis of variance (ANOVA) results and generated mathematical models. A multi-objective HTS algorithm was executed for generating 2-D and 3-D Pareto optimal points indicating the non-dominant feasible solutions. The proposed combined approach proved to be highly effective in predicting and optimizing the wire electrical discharge machining (WEDM) process parameters. Validation trials were carried out and the error between measured and predicted values was negligible. To ensure the existence of a shape-memory effect even after machining, a differential scanning calorimetry (DSC) test was carried out. The optimized parameters were found to machine the alloy appropriately with the intact shape memory effect.
70 citations
TL;DR: In this paper, the authors investigated geometrical errors such as cylindricity, circularity and diametral errors of a feature (a hole) produced from wire electrical discharge machining of Ti6Al4V alloy.
Abstract: This study investigates geometrical errors such as cylindricity, circularity and diametral errors of a feature (a hole) produced from wire electrical discharge machining of Ti6Al4V alloy wh...
69 citations
TL;DR: In this paper, powder mixed electrical discharge machining (PMEDM) is proposed and investigated for concurrent machining and coating an antibacterial layer on the surface of titanium workpieces.
TL;DR: In this article, a Ni55.8Ti shape memory alloy has been machined by wire electric discharge machining (wire-EDM) process and the effects of input parameters such as spark gap voltage, pulse on-time, pulse off-time and wire feed on productivity and surface quality have been investigated.
Abstract: In the present research, Ni55.8Ti shape memory alloy has been machined by wire electric discharge machining (wire-EDM) process. The effects of input parameters such as spark gap voltage, pulse on-time, pulse off-time, and wire feed on productivity, i.e., metal removal rate (MRR) and surface quality, i.e., mean roughness depth (Rz), have been investigated. Empirical modeling and ANOVA study have been done after conducting 16 experiments based on Taguchi’s L16 design of experiment technique. Ranking and crowding distance–based non-dominated sorting algorithm-II (NSGA-II) is used for process optimization. The error percentage varies within ± 6% between experimental results and the predicted results developed by NSGA-II. It has been observed that the wire-EDM machining of Ni55.8Ti alloy at optimum parameters resulted in improved MRR —0.021 g/min—and surface quality with good surface finish (Rz—6.2 μm) and integrity as significant reduction in the formation of cracks, lumps, and deposited layers.
TL;DR: Research studies on the application of EDM to different grades of stainless steel materials are reviewed and experimental and theoretical studies that have attempted to improve the process performance are described, by considering material removal rate, surface quality and tool wear rate.
Abstract: Electric discharge machining (EDM) is a material removal process that is especially useful for difficult-to-cut materials with complex shapes and is widely used in aerospace, automotive, surgical tools among other fields. EDM is one of the most efficient manufacturing processes and is used to achieve highly accurate production. It is a non-contact thermal energy process used to machine electrically conductive components irrespective of the material’s mechanical properties. Studies related to the EDM have shown that the process performance can be considerably improved by properly selecting the process material and operating parameters. This paper reviews research studies on the application of EDM to different grades of stainless steel materials and describes experimental and theoretical studies of EDM that have attempted to improve the process performance, by considering material removal rate, surface quality and tool wear rate, amongst others. In addition, this paper examines evaluation models and techniques used to determine the EDM process conditions. This review also presents a discussion on developments in EDM and outlines the likely trend for future research.
TL;DR: In this article, the grey relational analysis (GRA) is used as an optimization tool to find out the suitable process parameters for the machining of carbon nanotube-reinforced carbon fiber nanocomposite.
Abstract: In this research work, the grey relational analysis (GRA) is used as an optimization tool to find out the suitable process parameters for the machining of carbon nanotube-reinforced carbon fibre nanocomposite. In discrete space degree of relation of different data sets analysed by GRA. In this experimental work, four process parameters are selected, namely peak current (Ip), pulse on time (Ton), duty cycle (η) and gap voltage (Vg), and the significant effect on material removal rate (MRR) and tool wear rate (TWR) has been calculated. Both are considered as the main input variables for the selection of suitable process parameters. Predicted process parameters by GRA show significant increment of 0.000003 in MRR and significant reduction of 0.001904 in TWR.
TL;DR: An analytical and experimental investigation of the influence of the EDM parameters: Surface integrity and MRR was performed and indicated that the discharge current had the most influence on the surface roughness, followed by the discharge time.
Abstract: Electrical discharge machining (EDM) is a modern technology that is widely used in the production of difficult to cut conductive materials. The basic problem of EDM is the stochastic nature of electrical discharges. The optimal selection of machining parameters to achieve micron surface roughness and the recast layer with the maximal possible value of the material removal rate (MRR) is quite challenging. In this paper, we performed an analytical and experimental investigation of the influence of the EDM parameters: Surface integrity and MRR. Response surface methodology (RSM) was used to build empirical models on the influence of the discharge current I, pulse time ton, and the time interval toff, on the surface roughness (Sa), the thickness of the white layer (WL), and the MRR, during the machining of tool steel 55NiCrMoV7. The surface and subsurface integrity were evaluated using an optical microscope and a scanning profilometer. Analysis of variance (ANOVA) was used to establish the statistical significance parameters. The calculated contribution indicated that the discharge current had the most influence (over the 50%) on the Sa, WL, and MRR, followed by the discharge time. The multi-response optimization was carried out using the desirability function for the three cases of EDM: Finishing, semi-finishing, and roughing. The confirmation test showed that maximal errors between the predicted and the obtained values did not exceed 6%.
TL;DR: In this article, the influence of a modified pulse energy generator system on white-layer formation in electrical discharge machining has been analyzed in stainless steel machining under the presence of dielectric medium.
TL;DR: In this article, a comparative study of magnetic field assisted electrical discharge machining and conventional electrical discharge was conducted to analyze the discharge energy flowing and temperature distribution of workpiece, electrode tool and debris, and the effects of external magnetic field on the machining performance, environmental impacts and energy efficiency.
TL;DR: Rotary tool near-dry electrical discharge machining (RT-ND-EDM) as mentioned in this paper is a process variant of EDM, which utilizes two phase dielectric medium instead of a conventional liquid or gaseous medium.
Abstract: Rotary tool near-dry electrical discharge machining (RT-ND-EDM) is a process variant of EDM, which utilizes two phase dielectric medium instead of a conventional liquid or gaseous dielectric medium...
TL;DR: In this article, the effects of alternative manufacturing processes, such as Abrasive Water Jet (AWJ), Wire Electrical Discharge Machining (WEDM), and ultrasound vibration assisted milling (UVAM) with conventional milling during the manufacture of Alloy 718 parts were compared.
01 May 2019
TL;DR: In this paper, the authors proposed an electric discharge machining method for Ti-6Al-4V (Ti-6V 4V) alloy for hard-to-machine material.
Abstract: Titanium alloy (Ti-6Al-4V), being considered as hard-to-machine material, offers many challenges especially during conventional machining. Electric discharge machining could be a good option if it ...
TL;DR: Investigating surface generation, kerf width, discharge gap, material removal rate and wire degradation during WEDM of Ti6Al4V alloy found that, machined surfaces consist of multi-layered recast layer with the presence of cracks, holes as well as traces of materials from electrode wire.
TL;DR: In this paper, the effects of machining parameters of wire electrical discharge machining (WEDM) on magnesium metal matrix composite reinforced with Reduced Graphene Oxide (r-GO) were investigated.
Abstract: Taguchi coupled grey relation analysis is adopted to study the effects of machining parameters of Wire Electrical-Discharge Machining (WEDM) on magnesium metal matrix composite reinforced with Reduced Graphene Oxide(r-GO). An optimal combination of process parameter was expected to be finalized in this research to attain maximum Material Removal Rate (MRR) with a minimal surface roughness (Ra) value. The composite was fabricated through solvent based powder metallurgy route for varying percentage of r-GO. Experimental combination for WEDM of developed composite specimens were finalized to be L27 orthogonal array (OA) using Taguchi's method mainly based on the control factors namely reinforcement weight percentage (wt.%), pulse ON time (P1), pulse OFF time (P2) and wire feed rate (Wfd). ANOVA results revealed that wt.% and P1 are the most influencing parameters for MRR and Ra. Outputs scaleup that the developed regression model augments well with the experimental values. Using grey relation analysis (GRA) the optimal parameter was set and the final results obtained based on the optimal combination was found to be with a maximum MRR (18.38 mm3/min) and minimum Ra (3.29 μm). Traces of intermetallic formation are identified over the machined surface due to the action of machining parameters.
TL;DR: A literature review on the diversity of conventional and non-conventional materials that are used or have potential to be used as EDM electrodes is presented in this paper, where additive manufacturing of EDM electrode is also reviewed.
Abstract: Over the years, sinking electrical discharge machining has become one of the most important production technologies to manufacture very accurate three-dimensional complex components on any electrically conductive material. This article reports a literature review on the diversity of conventional and non-conventional materials that are used or have potential to be used as EDM electrodes. In addition, additive manufacturing of EDM electrodes are also reviewed.
01 Jun 2019
TL;DR: Nonconventional or advanced machining processes such as electric discharge machining, electrochemical machining and abrasive water jet machining have been widely used as a vi... as discussed by the authors.
Abstract: Nonconventional or advanced machining processes such as electric discharge machining, electrochemical machining, abrasive water jet machining, and laser beam machining have been widely used as a vi...
TL;DR: In this article, a comparative study has been conducted on the EDM performance of Ti-5Al-2.5Sn titanium alloy using different type of electrodes viz. copper, brass and zinc.
Abstract: Electro discharge machining (EDM) is extensively used in modern manufacturing industry because of its advantage over conventional machining method. Titanium alloys are the materials of research concern now for their extensive use in airframes and jet engines. Therefore, dimensional accuracy and surface integrity are the crucial concern for EDMed titanium alloys. The purpose of this study is to investigate the effect of process parameters and different type of electrodes on dimensional accuracy and surface integrity of EDMed Ti-5Al-2.5Sn titanium alloy. In this investigation, a comparative study has been conducted on the EDM performance of Ti-5Al-2.5Sn titanium alloy using different type of electrodes viz. copper, brass and zinc. The process performance has been measured by means of surface roughness (Ra), surface crack density (SCD), radial overcut (ROC) and recast layer. The outcome of using pulse on time, gap voltage, duty cycle, peak current as process parameters on the responses have been studied. Microstructural analysis has been carried out for the machined surfaces for different type of electrodes. Copper electrode provides a good surface finish and least radial overcut followed by brass and zinc electrodes. Thinner and uniform recast layer and higher surface crack density has been found on the EDMed surface machined by copper electrode compared to brass and zinc electrodes. Therefore, copper tool is recommended where higher precision and higher degree of surface finish is required for EDMed product.
TL;DR: An overview of ultrasonic vibration applications in electric discharge machining provides information about modes of UV application, impacts on parameters of performance, optimization and process designing on difficult-to-cut materials.
Abstract: 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.
TL;DR: In this paper, an attempt is made to explore the possibilities of modifying the dielectric by adding alumina (Al2O3) nanopowder for improving the machining performances.
Abstract: In this paper, an attempt is made to explore the possibilities of modifying the dielectric by adding alumina (Al2O3) nanopowder for improving the machining performances. The performance of newly developed nano powder-mixed electrical discharge machining (NPMEDM) process is compared with conventional EDM. Peak current, gap voltage and pulse-on time are taken as considerable process parameters to investigate material removal rate (MRR), surface roughness (SR), recast layer thickness, surface morphology, surface topography and induced residual stress. It is observed that the nanopowder-mixed dielectric medium gives better surface finish and higher metal removal rate as compared to conventional dielectric. The value of MRR increases from 32.75 to 47 mg/min and surface roughness improves from 2.245 to 1.487 μm. Thereafter, atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM) investigation of the machined surface reveals that presence of micro-crack, micro-hole and uneven deposition decrease substantially during NPMEDM process. Also, induced tensile residual stress on the machined surface significantly reduces in this modified process. Further, the basic mechanism of these processes are investigated by analysing pulse train discharge waveforms and reveals the better sparking stability of NPMEDM process, which results in the higher MRR and better surface quality.
TL;DR: In this paper, the authors present a method for machining intricate shapes in electrically conductive harder materials, such as metal matrix composites (MMCs), using wire electrical discharge machining (WEDM).
Abstract: Wire Electrical Discharge Machining (WEDM) is a competent method employed for machining intricate shapes in electrically conductive harder materials. Metal Matrix Composites (MMCs) possesse...
TL;DR: In this paper, the effectiveness of thermoelectric machining of aluminum-based SiC reinforced composites was investigated in magnetic field incorporated conventional Electrical Discharge Machining (EDM).
Abstract: The present study deals with the optimization of parameters to check the effectiveness of thermoelectric machining of aluminum based SiC reinforced composites. Here, hybrid ED machining of Al-SiC metal matrix composites (MMCs) is investigated in magnetic field incorporated conventional Electrical Discharge Machining (EDM). The input processing parameters, such as pulse-on/off duration, current were assessed to analyze their outcome on the response parameters in terms of material erosion rate (MER), microhardness (MH), surface roughness (SR) and recast layer formation. The experimental results witnessed decrease in microhardness values and reduced thickness of recast layer, accompanied by a significant effect on MER and surface finish while machining in the magnetic field coupled higher spark energy. The experimental results conferred the process stability and an excellent correspondence with experimental verifications.