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In this paper, the copper (Cu)-based multi-wall carbon nanotube (MWCNT) composite tools were fabricated using electro-co-deposition method. The composite tools were prepared from different MWCNT concentrated (0.5, 0.75 and 1g/L) electrolytic solution and these tools were utilized in electro discharge machining (EDM). The experiments were performed with varying discharge currents. The results indicated that the incorporation of MWCNTs into the copper matrix greatly influenced the machining performances. A lower rate of tool wear and higher material removal rate (MRR) were observed for the copper-based MWCNT composite tools at different discharge currents. The highest tool wear rate (TWR) was reduced by 45.68% and the MRR was improved by 63% for the Cu-MWCNT (0.5g/L) composite tool compared to copper coated tool. At higher discharge current, smoother machined surfaces were generated using copper-based MWCNT composite tools compared to the copper tools. The SEM image exhibits that the micro-crack-free machined surfaces were produced by using copper-based MWCNT composite tools. The migration of tool material to the machined surface was also reduced for copper-based MWCNT composite tools.

Ni-based superalloys fall under the category of difficulty in machining type material owing to their poor thermal conductivity and high strength at extreme temperatures. Machining such materials using the traditional approach is a tremendously difficult task. On the other hand, EDM, one of the most sophisticated electro-thermal manufacturing processes, is used to machine such materials. It is a well-known non-traditional machining process for generating parts that require accuracy, have complex shapes, and are small in size. However, the use of EDM in Ni-based superalloys has some disadvantages like poor surface finish and low material removal rate. So, to alleviate these disadvantages, researchers introduced powder mixed dielectric fluid in the EDM process. Further, the performance of this technique has been enhanced by studying the effect of various nano/micro-size particles and their concentrations in the dielectric medium. In this paper, the authors have reviewed the impact of non-electrical and electrical process parameters on the output responses when machining Ni-based superalloys using powder mixed EDM. The challenges faced during the conventional machining of Ni-based superalloys and the mechanism proposed for powder mixed EDM, especially under the influence of suspended powders into the dielectric medium have also been presented in this paper. Finally, future research areas of powder mixed EDM of Ni-based Superalloys, such as (i) its modelling and simulation and (ii) the effect of tool motion and powder properties on its performance, are discussed in brief.

Pure copper, copper-based alloys, brass, graphite and steel are the most common tool materials for the electrical discharge machining (EDM) process. The electrode material, which exhibits good conductivity to heat and electricity and possesses better mechanical and thermal properties, is preferred for EDM applications. The major problem with conventional electrodes like copper and graphite is their low wear resistance capacity. This study is on the fabrication of Cu–SiC composites as an electrode of EDM with improved wear characteristics for machining of hardened D2 steel which is widely used in die formation. Powder metallurgy route was used to fabricate the samples which was further followed by three-step sintering process. Copper metal was used as a matrix element which was reinforced with SiC in volume fractions of 10%, 15% and 20%. Based on the desirable properties for the EDM tool, the best composition of Cu–SiC composite tool tip was suggested and was further used for machining of D2 steel. The performance of newly developed Cu–SiC composite electrode in terms of surface roughness (SR), material removal rate (MRR) and tool wear rate (TWR) was explored, and it was compared with the pure copper electrode. Pulse on-time, pulse off-time and the input current were selected as the input process parameters. Result reveals that the TWR and SR were decreased by 12–18% and 10–12%, whereas the MRR was increased by 9–28% for Cu–SiC composite tool as compared to the pure Cu electrode. Adequacy of the results was checked by statistical analysis. The surface texture of tool and machined surface was analyzed using scanning electron microscopy (SEM). SEM micrograph revealed that surface cracks on composite tool tip were lesser than pure Cu tool tip, whereas the work surface was rough while machining with the copper tool surface. Therefore, the result indicates that the newly developed Cu–SiC composite tool can be used for machining of hard materials with EDM.

In this paper, experimental analysis was performed during micro-electrical discharge machining (micro-EDM) of titanium alloy Ti–6Al–4V (grade 5) using three types of tools viz. copper (Cu) tool, tungsten carbide (WC) tool, and synthetic graphite (Gr) grade three tool. The main process parameters were taken as (a) pulse on time ($T_{\mathrm{\text{on}}}$), (b) pulse off time ($T_{\mathrm{\text{off}}}$), (c) voltage (V), and (d) capacitance (C). The output responses were taken as the material removal rate (MRR) and tool wear rate (TWR). Taguchi method coupled with grey relational analysis (GRA) (L${}_{16}$ orthogonal array) technique was applied to optimize the input process parameters for both the responses. Scanning electron microscopy (SEM) analysis of the workpiece and tool was also performed to investigate the morphology of the machined surface and tool surface. Energy-dispersive spectroscopy (EDS) analysis was performed to investigate the elemental composition of the machined surface. The experimental finding reveals that tungsten carbide is the most suitable tool material for machining the chosen workpiece for obtaining optimal MRR and TWR. The optimum condition for the copper tool was found as 180V, 1000pf, 10$\mu$s ($T_{\mathrm{\text{on}}}$), and 10$\mu$s ($T_{\mathrm{\text{off}}}$). Meanwhile, the optimum parametric condition for tungsten carbide and graphite tools was found to be the same as 240V, 100pf, 20$\mu$s ($T_{\mathrm{\text{on}}}$), and 5$\mu$s ($T_{\mathrm{\text{off}}}$).

In the present study, aluminum alloy (Al/3.25Cu/8.5Si) composites reinforced with fly ash particles was fabricated using stir casting technique. Fly ash particles of three different size ranges 53–75, 75–103 and 103–125$\mu$m of 3, 6 and 9 weight percentages was reinforced in aluminum alloy. The effect of peak current, pulse on time, and pulse off time on surface roughness (SR), material removal rate (MRR) and tool wear rate (TWR) of electric discharge machining (EDM) was investigated. A central composite design using response surface methodology (RSM) was selected for conducting experiments, and mathematical models were developed using Design Expert V7.0.0 software. Analysis of variance (ANOVA) technique was used to check the significance of the models developed. Peak current was the major factor influencing the EDM of aluminum fly ash composites. The MRR, TWR, and SR of aluminum fly ash composites were also influenced by the size of the fly ash particles.

An experimental investigation was conducted to evaluate the machinability of a titanium alloy (Ti6Al4V) using copper (Cu), tungsten carbide (WC), and graphite (C) tools. Voltage (V), capacitance (pF), pulse-on time (T_on), and pulse-off time (T_off) were considered as the input machining parameters, whereas the material removal rate (MRR) and tool wear rate (TWR) were considered as the output machining parameters. A Taguchi L${}_{16}$ orthogonal array and gray relational analysis (GRA) were utilized to design and optimize the machining parameters for both responses. Artificial neural network (ANN) analysis was performed to predict the experimental outcomes. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were used to assess the surface morphology and determine the elemental composition of the machined surface. The results indicated that the optimum machining conditions for the copper tool were 150 V, 1000 pF, 15$\mu$s (T_on), and 15$\mu$s (T_off). However, the optimal machining conditions for the WC were 200 V, 100 pF, 25 $\mu$s (T_on), and 10$\mu$s (T_off), and the optimal conditions for the C were 200 V, 1000 pF, 20$\mu$s (T_on), and 25$\mu$s (T_off), respectively. The highest MRR achieved using the WC tool was 9.4510 mg/s, whereas the TWR of the Cu, WC, and C tools were 1.1039 mg/s, 1.0307 mg/s, and 1.2796 mg/s, respectively. The results showed that machining with the graphite tool had a higher TWR than machining with the Cu and WC tools.

The mechanical properties of Aluminum metal matrix composites (AMMCs) have made them a popular choice in various industries such as automotive, aerospace, and marine. However, their composition, which includes abrasive reinforcements, makes them difficult to machine using conventional techniques. So, unconventional machining processes play a vital role in the machining of these materials. Electrical discharge turning (EDT) is one of the configurations of electrical discharge machining (EDM) that is utilized to machine cylindrical-shaped workpieces. In this study, AMMC Al 7075/ZrO₂ was fabricated using the stir casting method. Further, investigated the effect of machining parameters of EDT, namely pulse Current (I), pulse on time (T-ON), and rotating speed (RPM), on Al 7075/ZrO₂ in terms of material removal rate (MRR), tool wear rate (TWR), and overcut (OC) using one parameter at a time (OPAT) method. The outcome of the experiment reveals that MRR, TWR, and OC are more impacted by pulse current than by rotational speed. A decrease in TWR was also found with an increase in pulse on time for all rotational speeds. The size of the craters and globules observed lower with 1400 RPM in the micrograph image.

Inconel 625 possesses excellent mechanical, chemical, and physical properties thus commonly used in different sectors. Due to its wide use, it becomes important to investigate its mechanical characteristics under die-sinking EDM. In this research, an empirical model is constructed to investigate the optimal parametric setting of die-sinking EDM. The experimental runs are developed using a Taguchi design. It has been observed from the analysis that peak current followed by pulse on time is the most significant parameter for MRR followed by pulse on time. However, the SR gives significant results on the pulse on time. The confirmatory test is conducted to validate the efficacy of the proposed method.

The area of metallurgy has witnessed many advancements in the development of novel electrically conductive materials that shows exceptional mechanical as well as thermal properties. Nonetheless, traditional machining techniques encounter difficulties while machining hard materials. In order to address this limitation, electrical discharge machining (EDM) has emerged as a widely utilised method for machining of intricate geometries and the hard materials. EDM is a category of thermo-electric process that employs rapid recurring sparks between the electrode and work material, eroding the material without direct contact. As there is no contact between the electrode and work material, the issues related to machining defects such as mechanical stresses, clattering, and vibration eliminates. However, EDM have some limitations like poor surface finish and low volumetric material removal. To overcome these kind of limitations, the introduction of metallic powder into the dielectric fluid has been explored in powder-mixed electric discharge machining (PMEDM). This introduction of powder during the process leads to enhance the conductive strength of the fluid and increases the spark gap distance between the electrode and counter material. The inclusion of powder has a significant impact on the performance of the EDM process. Hence, this review aims to facilitate researchers in comprehending the concept of PMEDM and to examine the process parameters required to achieve improved levels of quality.

The Antarctic Muon And Neutrino Detector Array (AMANDA) has been taking data since 2000 and its data acquisition system was upgraded in January 2003 to read out the complete digitized waveforms from the buried Photo-multipliers (PMTs) using Transient Waveform Recorders (TWR). This system currently runs in parallel with the standard AMANDA data acquisition system. Once AMANDA is incorporated into the 1 km³ detector IceCube, only the TWR system will be kept. We report results from a first atmospheric neutrino analysis on data collected in 2003 with TWR. Good agreement in event rate and angular distribution verify the performance of the TWR system. A search of the northern hemisphere for localized event clusters shows no statistically significant excess, thus a flux limit is calculated, which is in full agreement with previous results based on the standard AMANDA data acquisition system. We also update the status of a search for diffusely distributed neutrinos with ultra high energy (UHE) using data collected by the TWR system.