Electrochemical Spark Machining Research Articles

Optimization of Rotary-Magnet assisted ECSM on borosilicate-glass using machine learning

ABSTRACT Owing to the incapability of the existing techniques, Electrochemical Spark Machining (ECSM) is transpiring to micro machine the glass for potential applications in micro domain. However, in ECSM, the bubble accumulation and poor flushing lead to the generation of a non-uniform gas film, resulting in the deterioration of Hole Circularity (HC) and Surface Roughness (SR). Therefore, present communication is an attempt toward the concept of Rotary-Magnet assisted ECSM (RM-ECSM) to produce the micro holes in the borosilicate glass with better quality characteristics (higher HC and lower SR), which are required for better performance of glass vias in RF-MEMS. The evolutionary algorithm and Machine Learning (ML) have been adopted for optimization. From optimization, the values of optimal input parameters were obtained as follows: Applied voltage = 43.46 V; Electrolyte-temperature = 45.93 ֯ C; Pulse on time = 3.28 ms; Magnetic rotation = 551 rpm with corresponding values of HC and SR as 79.28% and 3 um respectively. Finally, these outcomes were validated by Levenberg-Marquardt algorithm (ML).

Parametric analysis and optimization of magnetic field-assisted electrochemical spark drilling (MF-ECSD)

Electrochemical spark machining (ECSM) is gaining tremendous recognition in the research fraternity due to its ability to machine non-conductive materials and hybridize with other forms of energy (ultrasonic and magnetic). In the present work, ECSM has been hybridized with magnetic energy by adding an electromagnetic unit in the in-house developed setup of magnetic field-assisted electrochemical spark drilling (MF-ECSD), to improve the material removal rate (MRR), machining depth (MD) and overcut (OC) of sodalime glass. Due to the addition of electromagnetic component into the setup, magnetic field of varying strengths were generated near the machining zone. Effect of magnetic field on size of bubbles and in exclusion of fragments from the machining region was examined during experimentations. This study also concentrated on the effect of selected input factors such as applied voltage, NaOH concentration, tool rotational speed (TRS) and magnetic field intensity (MFI) on MRR, MD, and OC. The regression model was developed based on experimental results and further analyzed to predict the pattern of responses beyond the selected range of parameters. The experimental and analytical results were in good corroboration and all the factors were found significant for enhancing the responses. Later, the Desirability Function technique for multi-objective optimization was applied to maximize MRR and MD and minimize OC which yielded an ideal value of 40.10 V, 30 wt%, 90 rpm, and 0 Tesla with overall desirability of 0.7238.

On the performance analysis of micro-hole drilling using magnetic field-assisted electrochemical spark machining

On the performance analysis of micro-hole drilling using magnetic field-assisted electrochemical spark machining

Experimental modelling and optimisation of WECSC of polymer nanocomposite

ABSTRACT Slicing of material using a thin wire reduces the loss of material and provides better cutting quality compared to any other machining techniques. Moving wire electrochemical spark machining (WECSM) is a hybrid, non-conventional wire slicing process, specially for non-conducting materials such as ceramics, composites and glasses. In this research article, alumina epoxy nanocomposite (AENC) has been taken as a workpiece. AENC is a polymer-based nanocomposite with a property of mixed nature such as ceramics and polymer. Due to its high electrical insulation performance, AENC is in demand in various applications. However, its mixed properties limit the machining capabilities for various applications. In the present work, modelling of the moving WECSM process has been performed using response surface methodology, and GRA with entropy method was applied for finding the optimum set of parameters. The results show that the optimal machining performances for material removal rate, surface roughness and kerf taper were obtained at 55 V applied voltage, 2.5 m/min wire velocity, 200 g/l electrolyte concentration and 200 µs pulse-on time.

EXPERIMENTAL STUDY OF GLASS MACHINING PROCESS PARAMETERS IN ELECTROCHEMICAL SPARK MACHINING PROCESS

Advanced machining processes show a very crucial role in the machining of high-strength brittle materials. However, process efficiency and cost are still issues in currently used advanced machining processes. Quartz glass has broad application in the area of microfluidics systems, but the high brittleness of this material poses difficulty in its machining. In the present work, the machining of quartz glass is performed through Electrochemical spark machining processes (ECSM) which is one of the hybrid advanced machining processes. Input machining parameters are voltage, duty cycle under the constant condition of electrolyte concentration and tool electrode rotation. Input machining parameter effects are observed on the surface roughness of the machined quartz glass workpiece. Taguchi method is used to identify best optimal parameters using full factorial.

Determination of Nanoindentation Behavior of HAZ on Glass Material Machined via ECSM Process through Simulation Approach.

The current study develops a numerical model to investigate the nanoindentation behavior of heat-affected zones (HAZ) on glass material produced via the electrochemical spark machining (ECSM) method. Initially, microchannels were created using the ECSM method on soda–lime glass. Following that, a nanoindentation test was conducted to quantify the Young’s modulus and hardness of the glass sample. After that, a numerical model based on finite elements was created to characterize the changes in mechanical characteristics of HAZ. According to the findings, increasing the electrolyte concentration from 10 to 30% increases the intensity of electrochemical discharges, and thereby decreases the hardness of the work material by 16.29 to 30.58% compared to unmachined glass. The results obtained from the simulation are in close agreement with the experimental values. The maximum error obtained between simulation and experimental results is only 4.18%.

Energy Channelization Analysis of Rough Tools Developed by RM-MT-EDM Process during ECSM of Glass Substrates.

In the present work, the effect of tool surface roughness on energy channelization behavior was analyzed during the fabrication of micro holes by an electrochemical spark machining (ECSM) process. In this study, rough tools were fabricated by a rotary mode multi tip electric discharge machining (RM-MT-EDM) process. The electrical characterization was also carried out to investigate the electric field intensity over the surface of tool electrode, and it was found that the use of rough tools improves the electric field intensity by 265.54% in comparison to the smooth tool electrodes. The use of rough tools in the ECSM process forms thin and stable gas film over the tool electrode, and as a result the rough tools produced high frequency spark discharges. Energy channelization index and specific energy were considered as response characteristics. The use of rough tools improves energy channelization index by 248.40%, and the specific energy is reduced by 143.263%. The material removal mechanisms for both of the processes (RM-MT-EDM and ECSM process) have also been presented through illustrations.

Micro-channel fabrication on GFRP composite through electrochemical spark machining method and optimization of process parameters

In the present study, fabrication of micro-channel on glass fiber reinforced plastic (GFRP) sheet has been performed through micro-electrochemical spark machining process. Box-Behnken design has been followed to conduct experiments and the influence of machining parameters and their ranges that is, applied voltage (50 V–60 V), duty factor (35%–45%), electrolyte concentration (20–30 wt%), and pulse frequency (6–10 kHz) on the micro-channel quality has been investigated. The width of micro-channel (WMC), delamination extent (DE), and heat-affected zone (HAZ) are considered as the responses. Response surface method (RSM) with desirability analysis and multi-objective optimization are utilized to optimize the process. The minimum observed WMC, DE, and HAZ are 532.81, 1.09, and 50.52 μm respectively which are obtained at machining voltage: 50 V, duty factor: 35%, concentration: 20 wt% of NaOH, and pulse frequency: 10 kHz. The fiber breakage and re-deposition/adhesion of broken fiber and matrix materials are observed at the edges of the micro-channel.

Improvement in energy channelization behaviour during micro hole formation in Y-SZ ceramic with magnetic field assisted ECSM process

In the present investigation, an energy channelization behavior was improved while machining micro holes in the Yttria–stabilized zirconia (Y-SZ) under magneto hydrodynamic conditions. The integration of magnetic field with electrochemical spark machining (ECSM) process forms the stable and thin gas film on the tool electrode. The subsequent breakdown of this film improves the discharge frequency and increases the discharge current by 18%. The underlying process and material removal mechanisms were demonstrated by using the evidence from discharge signals, gas film images, SEM, and optical images of work material. The stirring action provided by the magnetic field in ECSM process helps to flush out the sludge and stray bubbles from the machining region. In comparison to the ECSM process, the hole depth and aspect ratio were improved by 84.37% and 120%, respectively. Thermal spalling is the leading phenomenon in the material removal process for Y-SZ instead of melting and chemical etching, as in the case of glass substrates. Energy channelization analysis is also carried out to establish the correlations between energy-based parameters and responses. The combination of higher applied energy with small pulse durations is suggested to produce deep holes. The parametric investigation, regression modeling, and optimization for the MFA-ECSM process are also carried out to explore the process behavior.

Multi-objective optimization of TW-ECSM process parameters for machining of advanced non-conducting material

Travelling wire electrochemical spark machining (TW-ECSM) is newly evolved and developed hybrid machining process for the machining of advanced non-conducting materials which possess significant values of the properties like high strength, high wear and fatigue resistance, high refractoriness and high strength to weight ratio, etc. The control parameters like voltage, wire feed rate, electrolyte concentration and inter-electrode gap were selected as Input Parameters and Material Removal Rate (MRR), and Surface Roughness (SR) were the corresponding output responses. In present work, for multiobjective optimization and purpose of better control of machining parameters, three approaches, grey-relational analysisprincipal component analysis (GRA-PCA), fuzzy logic and desirability function approach are used to determine the optimal combination of TW-ECSM process variables. Results of fuzzy logic and GRA-PCA approach are found comparable while desirability function approach is found to be capable of predicting the optimal responses at such levels of process variables also at which experiments are not performed. Consequences of the applied approach in the present work are also validated by conducting the confirmatory experiments and results are found in well agreement with the predicted results.

Optimization of material removal rate of tempered glass by using electrochemical spark machining

Electrochemical Spark Machining (ECSM) is a hybridization process of (EDM) and (ECM) in which material removal is initiated by the impact of electrolysis and electroplating phenomenon based on faraday’s law. In this investigation, the development of electrochemical spark machining is conducted which is the conversion from the conventional drilling machine. The L9 orthogonal array was employed in this study to optimize the regulated parameters using a gravity feed method with the tool & electrolyte in a static condition. MRR has undergone the analysis of variance, which resulted that voltage is the most significant parameter that has higher effectiveness on material removal from the substrates, followed by power cycle and concentration. The optimized value was verified by performing the confirmation experiment. The optimal predicted value of MRR in ECSM is 0.23366 mm3/min at the control factors values of voltage 80 V, electrolyte concentration 30 % & power cycle 80 %.

Improvement in Machining Performances of SiC Workpiece Using TW-Electro Chemical Spark Machining

Electrochemical Spark Machining (ECSM) is applicable to machine the materials which are non-conducting. The present research work extended the application area of ECSM process from non-conducting materials to semiconducting materials i.e. silicon carbide (SiC). In order to enhance material removal rate (MRR) and to reduce the entrance oversize (OS) as well as surface roughness (SR), the magneto-hydrodynamic (MHD) convection approach is utilized. The magnetic field (MF) produces Lorentz forces during electrolysis process. This MF assisted travelling-wire electrochemical spark machining (TW-ECSM) process provides better flushing in narrow gap between work material and tool electrode by clearing the zone from debris particles to obtain a stable spark. It is evident from results that presence of magnetic field improved MRR from 19.15% to 200% and reduced SR and OS from 16.86% to 48.58% and from 11.37% to 21.27% respectively.

Review on micromachining of pyrex glass using wire-ecdm

Pyrex glass has a huge range of applications such as micro optics, mechanical inertial sensors, micro-pumps, micro fluidic devices, biochip etc because of its excellent physical and chemical properties such as high chemical resistance, heat resistance, high electrical isolation, large optical transmission range, biocompatibility, low thermal and electrical conductivity, good chemical stability. Due to the hardness and brittleness properties, Pyrex glass has poor mach inability. It is very complicated to machine Pyrex glass by using conventional processes. Travelling wire electrochemical spark machining (TW-ECSM) is an emerging technique for micromachining of non-conductive materials. In TWECSM, the material of the work piece is melted, vaporized and eroded due to the transmission of spark energy to the work piece. Surface roughness is a very important aspect if we are doing micro aching of a material. The literature reveals the work done by various researchers for the micromachining of Pyrex glass. However very less work has been done on Pyrex glass. So in this paper, work done by various researchers on Pyrex glass, Use of TW-ECDM for micro aching is reviewed, scopes for further research have been identified.

Modeling and Response Optimization of Traveling Wire Electro-Chemical Spark Machining of Borosilicate Glass Using Hybrid Approach

Traveling Wire Electro-Chemical Spark Machining (TW-ECSM) process is a new innovative thermal erosion-based machining process suitable for cutting electrically nonconductive materials using tool electrode in the form of wire. This article attempts experimental modeling of TW-ECSM process using a hybrid methodology comprising Taguchi methodology (TM) and response surface methodology (RSM). The experiments were carried out on borosilicate glass using L[Formula: see text] orthogonal array (OA) considering the input parameters like applied voltage, pulse on-time, pulse off-time, electrolyte concentration and wire feed velocity along with process performances such as material removal rate (MRR), surface roughness (R[Formula: see text] and kerf width (K[Formula: see text]. The interaction influence of input parameters on process performances was also discussed. Further, multi-objective optimization (MOO) of response performances of TW-ECSM process is executed using a coupled approach of grey relational analysis (GRA) and principal component analysis (PCA). The optimal process parameter setting illustrates the improvement of MRR by 171%, diminution of Ra and K[Formula: see text] by 27% and 8% against the initial parameter settings. Moreover, irregular cutting of kerf width and surface characteristics were also scrutinized using scanning electron microscope (SEM).

Machining issues on Electrochemical Spark Machining—A review

Electrochemical Spark Machining is a hybrid advance machining process of Electrochemical Machining and Electric discharge machining which can machine conducting materials as well as non-conducting materials. Electrochemical Spark Machining is focused for melting, vaporizing, and chemical etching the undesirable material from the workpiece. It is appropriate for micromachining of complex geometry with a high aspect ratio. In recent years, researches have studied several aspects of machining related to ECSM. This review paper is an effort to understand the key issue related to machining on ECSM. The review reports that the kind of electrolyte, applied voltage, tool materials, tool rotation affect the machining process in terms of surface roughness, aspect ratio, and MRR. The review paper finally lists down certain areas for future research in ECSM.

Experimental Set Up to Improve Machining Performance of Silicon Dioxide (Quartz) in Magnetic Field Assisted TW-ECSM Process

In the present scenario, machining of the pioneering engineering materials such as various ceramics and composites which possess high hardness, brittleness, strength and electrically insulated becomes very difficult. This study focuses on the development of magnetic field assisted traveling wire electrochemical spark machining (MF-TWECSM) process set up and its utilization for the machining of electrically insulated materials. TW-ECSM process is a combination of the Wire-EDM and ECM processes. In this process, effects of the electrochemical reaction and electric spark are responsible for the material removal from the workpiece. Quartz found to be suitable as work material due its high hardness, good chemical stability and piezoelectric properties. Magnetic field has been applied during the machining for better circulation of the electrolyte during experimentation. Enhanced electrolyte circulation improves the efficiency of the process resulting in higher material removal rate (MRR) of the work material and reduction in the discharge current during experimentation. The improvement in MRR with magnetic field was found in the percentage range of 9% to 200% during experimentation. For the very first time, a brass wire with diameter 0.1 mm has been used during TW-ECSM process.

Electro-chemical spark machining–based hybrid machining processes: Research trends and opportunities

Shaping of the difficult-to-machine non-conductive materials such as glass, quartz and ceramic is much difficult and uneconomical by existing machining processes. As a result, wide applicabilities of these materials are still limited. Even though these materials are highly required in the field of the modern industries. To overcome the problem, a new machining method has been proposed by researchers by combining the features of electro-chemical machining and electro-discharge machining. Such combined machining process is called as electro-chemical spark machining process. Such developed machining method becomes an appropriate process for machining of non-conductive materials with significant improvement in productivity as compared to the electro-discharge machining and electro-chemical machining processes. In this article, the role of electro-chemical spark machining for machining of the non-conductive materials has been summarized and focused on the future research possibilities in the same area. This article also focuses on mechanism, process and performance parameters, variants and new developments related to the electro-chemical spark machining. As a result, this review article becomes beneficial for researchers to understand the phenomena of the electro-chemical spark machining process as well as further development in the same area.

Experimental Investigations and Multi-response Optimization of Silicon Dioxide (Quartz) Machining in Magnetic Field Assisted TW-ECSM Process

Travelling wire electrochemical spark machining (TW-ECSM) has the potential for the machining of advanced non-conducting materials like glass, quartz, silicon nitride, various composites and ceramics. In the present work, experimental investigations have been conducted on the magnetic field assisted travelling wire electrochemical spark machining (TW-ECSM) process. In this technique, a magnetic field has been introduced in the TW-ECSM process in order to improve the machining performance in terms of improved material removal rate (MRR) and reduced surface roughness (Ra) of non-conducting materials. Material removal rate (MRR) and surface roughness (Ra) were selected as the responses during the experimentation. The experimental results revealed that the magnetic field assisted approach gives reduced values of Ra and increased MRR when compared to the TW-ECSM process. The minimum and maximum values of surface roughness and MRR were found to be 7.42 µm and 0.19 mg/min with magnetic field assisted TW-WCSM process respectively. The optimization function has been developed to minimize Ra and maximize MRR for obtaining the optimum process parameters.

An experimental investigation on developed WECSM during micro slicing of e-glass fibre epoxy composite

The e-glass fibre epoxy composite is a nonconductive ceramic material, and it is difficult to machine by any well-known non-conventional machining methods like electrical discharge machining, wire electrical discharge machining, etc. This material can be machined with conventional machining but compromise with accuracy, surface texture, etc. However, conventional machining methods cannot be applied to the micro machining range for manufacturing of ultra-precision parts. Keeping in view, travel wire electrochemical spark machining (WECSM), a hybrid machining technique which is a combination of electrochemical machining (ECM) and wire electric discharge machining (WEDM) is used to machine e-glass fibre epoxy composite. This paper presents the results during machining of e-glass fibre epoxy composite on designed and fabricated WECSM. The numbers of experiments have been carried out to investigate the effect of different parameters of developed WECSM on machining performance characteristics such as material removal and spark gap width. Test results revel that the width of micro slice varied from 220 to 223 μm when slicing operation was performed with 200 μm diameter brass wire. The practical research analysis and test results present in this paper will provide new guidelines to the manufacturing engineers and upcoming researchers.

Experimental Study of Traveling Wire Electrochemical Spark Machining of Borosilicate Glass

Machining performance study of newly developed machining processes has always been a challenge to make them industrially viable. Traveling wire electrochemical spark machining (TW-ECSM) is a newly developed hybrid process in the area of nontraditional machining process which can be effectively utilized for difficult-to-cut electrically nonconductive very hard and brittle materials. Present paper discusses the investigations showing the effect of input process variables on material removal rate (MRR) and kerf width (K w) during the cutting of borosilicate glass using self-developed tabletop TW-ECSM setup. The experimental studies are conducted under varying applied voltage, pulse-on time, pulse-off time, electrolyte concentration, and wire feed velocity. The experimental results shows that MRR and K w increase with increase in applied voltage as well as pulse-on time, but these performance characteristics decrease with increase in pulse-off time. MRR and K w increase with increase in electrolyte concentration at certain value (25% wt.) and beyond that value they start to decrease. Moreover the machined kerf width and surface finish were also analyzed by scanning electron microscope (SEM).