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Thin-walled annular parts are widely used in the aerospace industry. There are some irregular island structures with non-periodic distribution on the inner surfaces of annular parts, which poses a significant challenge to manufacture such annular parts using conventional mechanical methods. Electrochemical machining (ECM) has exhibited good prospects for manufacturing thin-walled annular parts, with the advantages of no tool wear, no processing deformation and a high material removal rate. However, there is little research related to fabricate convex structures on the inner surfaces of annular parts, although ECM is vital to the machining of thin-walled annular parts. In this study, a flexible cathode tool was used to machine irregular convex structures on the inner surfaces of annular parts via co-rotating ECM. The complex motion of the cathode tool and conductive slider was simulated using matrix equations, and the digital simulation of the material removal process was realized based on matrix equations and Faraday's law. Based on the mathematical model, a design method for a flexible cathode tool was developed, and three main parameters were determined: the position of the window, radius of the cathode, and width of the window. Comparative experiments were performed using the flexible and conventional cathode tools. The results showed that the selective removal of convex structures was achieved by using the flexible cathode tool. The insulated sheet needed to be attached to the position where the convex structure was retained. An aero-engine casing with many irregular island structures on the inner surface was successfully machined. The height of the fabricated island structure is 6 mm. The sidewall thickness of the aero-engine casing is 1.2 mm. Therefore, co-rotating ECM with a flexible cathode tool offers excellent machining ability for irregular island structures on the inner surfaces of annular parts. [Display omitted] • Co-rotating electrochemical machining using a flexible cathode tool is proposed to machine structures on the inner surface of annular parts. • Based on the mathematical model of the material removal process, a design method for a flexible cathode tool is proposed. • The selective retention of island structures is achieved by adding a movable conductive slider in a conventional cathode window. • An aero-engine casing with many irregular island structures on the inner surface is successfully machined. [ABSTRACT FROM AUTHOR]

This study investigated the impact of varying atomization amounts on composite machining involving both atomized electrical discharge ablation machining and electrochemical machining (EDAM-ECM). Additionally, this study examined the effects of different atomization amounts on the material removal rate, relative electrode wear rate, processing waveforms, surface roughness, surface morphology and elements, and the EDAM-to-ECM ratio. Moreover, a theoretical model for describing the material removal process in composite processing was developed. Furthermore, the effect of the ECM ratio on the processing results was quantitatively analyzed through the integration of statistical circuits with a formula for calculating recast layer thickness. The model was used to predict and select the optimal atomization amounts required to achieve recast layer removal during processing. The results revealed that at an atomization amount of 200 mL/min, 16.7% of the total material removal was attributable to ECM, indicating the successful removal of the recast layer. At this atomization amount, the fabricated sample maintained a machining precision of 0.02 mm. [ABSTRACT FROM AUTHOR]

Zirconia is a ceramic material having a wide range of applications in industries owing to its excellent properties like high strength-to-weight ratio, biocompatibility, insulating, high wear, thermal resistance, and chemical stability over conventional materials. These properties pose a significant challenge for machining at the micro-level with considerable accuracy and preciseness. The ECDM is a low-cost hybrid machining technique with great potential to machine such materials. Barely any simulated or numerical work has been available for machining zirconia material through the ECDM process. In this study, a finite element model (FEM) is developed to predict the material removal rate (MRR) of the zirconia material using the temperature distribution plots through the electrochemical discharge machining process (ECDM) for different parametric conditions using a single spark mechanism. The simulation results reveal the increase of 316.9 µg in MRR by increasing electrolytic concentration from 15% to 30% wt. However, a small error was found between simulated and experimental results, which might be due to the assumptions during the study. This study will provide new guidelines during the processing of zirconia material for predicting the material removal rate for future manufacturing engineers. [ABSTRACT FROM AUTHOR]

Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The monitoring of micro machining gap and the control of machining status within the gap have become bottlenecks in the research and development of micro electrochemical machining (ECM). General electrical signals are difficult to reflect the status of micro machining gap. Electrolytic products in micro machining gap are prone to precipitation and retention, leading to unstable material removal process. Micro ECM urgently requires gap status monitoring and feedback control. To realize gap status monitoring, a sensors-integrated silicon electrode, with a micro temperature sensor and a micro conductivity sensor on the silicon electrode near-front sidewall, is proposed innovatively in this study. Based on bulk silicon process and electroplating process, sensors-integrated silicon electrodes are designed and fabricated. Based on the signal processing system built for the temperature and conductivity sensor, the temperature and conductivity detection functions are verified and the sensors are calibrated. Micro ECM experiments with sensors-integrated silicon electrodes are carried out and micro holes with 200 μ m depth are machined. For the conductivity sensor on the sensors-integrated silicon electrode, due to the affection of electrolytic environment, the function surface is contaminated and damaged, and the structural design needs to be further improved. For the temperature sensor, it is not affected by the electrolytic environment due to insulation-film's protection, and reliable temperature monitoring is achieved in micro ECM. The detection results indicate that the temperature inside the machining gap has increased by 20 °C due to the electrochemical thermal effect and resistance thermal effect in micro ECM, and the temperature shows an increasing trend while machining depth increasing. The feasibility of process monitoring with sensors-integrated silicon electrode in micro ECM is preliminarily verified. [ABSTRACT FROM AUTHOR]

Injection moulds are crucial to produce plastic and lightweight metal components. One primary associated challenge is that these may suffer from different types of failures, such as wear and/or cracking, due to the extreme temperatures (T), thermal cycles, and pressures involved in the production process. According to the intended geometry and respective needs, mould manufacturing can be performed with conventional or non-conventional processes. This work focuses on three foremost alloys: AMPCO® (CuBe alloy), INVAR-36® (Fe-Ni alloys, Fe-Ni36), and heat-treated (HT) steels. An insight into the manufacturing processes' limitations of these kinds of materials will be made, and solutions for more effective machining will be presented by reviewing other published works from the last decade. The main objective is to provide a concise and comprehensive review of the most recent investigations of these alloys' manufacturing processes and present the machinability challenges from other authors, discovering the prospects for future work and contributing to the endeavours of the injection mould industry. This review highlighted the imperative for more extensive research and development in targeted domains. [ABSTRACT FROM AUTHOR]

Zr-based metallic glasses (MGs) are promising materials for mold manufacturing due to their unique mechanical and chemical properties. However, the high hardness of metallic glasses and their tendency to crystallize at high temperatures make it challenging to fabricate precise and smooth microscale structures on metallic glasses. This limitation hampers the development of metallic glasses as molds. Jet electrochemical machining (jet-ECM) is a non-contact subtractive manufacturing technology that utilizes a high-speed electrolyte to partially remove material from workpieces, making it highly suitable for processing difficult-to-machine materials. Nevertheless, few studies have explored microgroove structures on Zr-based MGs using sodium nitrate electrolytes by jet-ECM. Therefore, this paper advocates the utilization of the jet-ECM technique to fabricate precise and smooth microgroove structures using a sodium nitrate electrolyte. The electrochemical characteristics were studied in sodium nitrate solution. Then, the effects of the applied voltages and nozzle travel rates on machining performance were investigated. Finally, micro-helical and micro-S structures with high geometric dimensional consistency and low surface roughness were successfully fabricated, with widths and depths measuring 433.7 ± 2.4 µm and 101.4 ± 1.6 µm, respectively. Their surface roughness was determined to be 0.118 ± 0.002 µm. Compared to non-aqueous-based methods for jet-ECM of Zr-based MGs, the depth of the microgrooves was increased from 20 μm to 101 μm. Furthermore, the processed microstructures had no uneven edges in the peripheral areas and no visible flow marks on the bottom. [ABSTRACT FROM AUTHOR]

CMSX-4 nickel base superalloy is the second-generation alloy of this single crystal, which has improved its mechanical properties due to the lack of grain boundaries. According to the working conditions in using this superalloy, achieving less surface defects and lower surface roughness after the manufacturing process is very important. Therefore, the comparison of the surface of this superalloy after grinding, wire electro discharge machining (WEDM) and electrochemical machining (ECM) has been investigated by scanning electron microscope (SEM) and surface roughness. Surface roughness after WEDM, ECM and grinding are 3.337, 0.549, and 0.458 micro-meter, respectively. ECM and grinding processes are suitable from the point of view of surface roughness. On the other hand, in the SEM images after ECM, the defects caused by this process were not observed (compared to the other two processes). Besides, hardness after WEDM, ECM and grinding are 38.9, 39.7 and 40.1 HRC respectively. To conclude, the ECM process has desirable results and is a suitable alternative process for manufacturing parts with smooth surface and less surface defects. [ABSTRACT FROM AUTHOR]

Electrochemical machining is a machining method that uses electrochemical reactions to remove material from a workpiece. The method involves using an electrolyte and an electric current for material removal to occur in a controlled manner. The machining method is also used in the case of workpieces made of hard materials or difficult to process by other methods. The experimental research whose results were included in the paper sought a deeper understanding of the mechanisms of the machining process and the interactions between the workpiece material and the electrolyte. The experimental research involved the configuration of a machining system, the preparation of the samples, the performance of the experimental tests resorting to the variation of some input factors such as the voltage applied to the electrodes, the size of the gap between the electrodes, the composition of the electrolyte. The experimental test planning method was used. The mathematical processing of the experimental results was carried out using specialized software, which is based on the least squares method. Empirical mathematical models were thus established, highlighting the intensity of the influence exerted by the input factors on the magnitude of the roughness parameter Ra. It was found that, among the input factors considered, the strongest influence is exerted by the gap size, followed by the voltage applied to the electrodes. [ABSTRACT FROM AUTHOR]

Super high-strength steel has an important demand in manufacturing key components inside gear transmission systems of heavy-duty helicopter owing to its superior comprehensive mechanical property. However, the high-performance machining of super high-strength steel is confronted with great challenges owing to the high cutting force, serious tool wear, and impoverished machining quality. Comparative trials in grinding ultra-high strength steel under conventional grinding (CG) and ultrasonic vibration-assisted grinding (UVAG) processes were conducted with white alumina (WA) and microcrystalline alumina (MA) wheels. Grinding performances, including grinding forces, force ratio, ground surface quality, and abrasive wheel morphologies, were discussed in detail. Experimental results show that the separation property between wheels and workpiece in UVAG process contributes to alter the material removal process, reducing the chip clogging and adhesion. In addition, the micro-fracture of abrasive grains can effectively improve the self-sharpening ability of abrasive wheels. UVAG possesses a shorter grinding scratch owing to the ultrasonic vibration than that of CG, which is beneficial to improve machining quality under the same wheel. Meanwhile, in comparison of WA wheels, MA wheels have the narrower grinding marks and better surface quality, which is due to the sharp edges produced by its higher strength, toughness, and excellent self-sharpening. [ABSTRACT FROM AUTHOR]

A new co-rotating electrochemical machining method is presented to machine the complex structure inside annular parts such as flame tubes and aero-engine casings. Due to the unique shape and motion of electrodes, it is difficult to accurately compute the electric field intensity in the machining area. In this paper, the complex electric field model is simplified by conformal transformation, and the analytical solution of electric field intensity is exactly calculated. A material removal model is built on the basis of the electric field model, and the dynamic simulation of the material removal process is realized. The effects of the cathode radius, applied voltage, feed rate and initial interelectrode gap on the interelectrode gap (IEG) and material removal rate (MRR) are analyzed. The simulation results indicate that the MRR is always slightly less than the feed rate in a quasi-equilibrium state, resulting in a slow reduction in IEG. In addition, the final machining state is not affected by the initial IEG, and the MRR in a quasi-equilibrium state is determined by the feed rate. Several comparative experiments were carried out using the optimized processing parameters, in which the MRR and IEG were measured. The convex structures were successfully machined inside the annular workpiece with optimum machining parameters. The experimental results are in good agreement with the theoretical results, indicating that the established model can effectively predict the evolution process of MRR and IEG. [ABSTRACT FROM AUTHOR]

Spark-Assisted Chemical Engraving (SACE) is a hybrid manufacturing process used to micromachine glass and other hard-to-machine materials. A tool-electrode, integrated in an electrochemical cell, is used to generate sparks and locally heat the workpiece surface, which enables material removal through thermally-promoted etching by an alkaline electrolytic solution. A challenge in SACE machining is the precise in-situ monitoring of material removal for process control; (electro)mechanical solutions exist, however they are complex to realize, hence limiting the use of the SACE process for precision glass machining in industry and academia. The present study introduces novel, quantitative and practical methods of obtaining process information by measuring the current flowing through the electrodes for both workpiece surface referencing by probing and SACE machining feedback and control strategies. During workpiece surface probing operations, a spike in the average current signal was observed at a repeatable tool height with respect to the workpiece, which can be used to accurately and repeatably measure the machining gap in a probing operation. Furthermore, three distinct current modes were identified and related to a different gas film state during machining of microchannels, paving the way for active control of gas film stability through monitoring of the current signal. [Display omitted] • The current signal in SACE can be used to enable in-situ monitoring on process status. • Development of a contactless method for non-conductive workpiece surface probing. • Probing can be realized by identifying the current spike during tool descends. • During machining, gas film stability can be determined by discharge activity. [ABSTRACT FROM AUTHOR]

Electrochemical diamond drilling (ECDD) is a novel hybrid machining process that offers an efficient solution for machining of super alloys without distressing their internal properties. The material removal process in ECDD occurs through a combination of anodic dissolution and mechanical abrasion, making it an effective solution for machining two-phase alloys that are prone to differential dissolution of phases. Ti6Al4V alloy is one such example, which has poor surface finish when electrochemically machined due to the different dissolution potentials of its α and β phases. The present study suggests the use of response surface methodology (RSM) for optimizing the ECDD process. Using central composite design (CCD), 30 experimental runs were performed to analyze the effect of input parameters—voltage, tool feed rate, concentration of electrolyte and tool RPM on material removal rate (MRR) and surface roughness (Ra). The result showed that the use of diamond abrasive tool in ECDD enhances the surface finish by removing the TiO2 layer and burrs through mechanical abrasion, while increasing MRR through electrolytic dissolution. The study found that the optimized conditions for ECDD produced an MRR of 0.041 gm/min and Ra of 3.986 µm which were 5.12% and 2.1% different from the values predicted by the regression model. The study concludes that ECDD can be used to produce high-quality surfaces on two phase alloys while preserving their internal properties, making it a valuable tool for machining of wide range of materials. [ABSTRACT FROM AUTHOR]

Metalworking operations rely on the successful application of metalworking fluids (MWFs) for effective and efficient operation. Processes such as grinding or drilling often require the use of MWFs for cooling, lubrication, and chip removal. Electrochemical machining processes require electrolyte flow to operate. However, in those machining operations, a fundamental understanding of the mode of action of MWF is lacking due to the unknown flow dynamics and its interaction with the material removal during the process. Important information on the behaviour of MWFs during machining can be obtained from specific experimental flow visualisation studies. In this paper, promising flow visualisation analysis techniques applied to exemplary machining processes (grinding, sawing, drilling, and electrochemical machining) are presented and discussed. Shadowgraph imaging and flow measurements, e.g., particle image velocimetry, allow the identification of typical flow and MWF operating regimes in the different machining processes. Based on the identification of these regimes, efficient machining parameters and MWF applications can be derived. In addition, detailed experimental analyses of MWFs provide essential data for the input and validation of model development and numerical simulations within the Priority Programme SPP 2231 FluSimPro. [ABSTRACT FROM AUTHOR]

Many newer higher strength materials are being synthesized for variable automobile, aerospace and manufacturing applications in the present scenario. Since it is very difficult to cut such materials using conventional machining process, it is important to utilize unconventional machining process. In the present study, a detailed survey has been made to analyze the influence of various process parameters, effects of electrodes, optimization and electrolytes on performance measures in Electro chemical machining process. The effects of pulse related parameters on electrode materials, coating materials and its thickness on material removal, overcut and surface topography were investigated under different perspectives such materials, electrolyte and machining parameters. From the detailed literatures, it has been inferred that still lot of research works have been required to find the suitable electrolytes and their combination during the machining process. It has also been found that the performance measures of the machining process can be improved by adopting different and suitable optimization algorithms. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) is a promising method for the manufacturing of complex geometries. Electron beam melting (EBM) is one of the powder bed AM processes which is used for hard metals to produce near and net-shape parts. The most encountered drawback in the EBM process is the surface quality, which plays a critical role on service life of the parts, particularly under variable loads. Electrochemical machining (ECM) is a non-traditional machining method in which the workpiece can be machined regardless of its hardness. This research presents a post-processing method for AM parts and dissolution mechanism of γ-TiAl alloys in order to improve the surface quality. For that purpose, Ti-48Al-2Cr-2Nb alloy is chosen and the sample parts are manufactured by EBM process. EBMed parts are machined using different ECM process parameters such as cathode material, feed rate, and electrolyte conductivity. Measurement results show that better surface roughness (Sa) values are obtained for the brass cathode. Sa values for the copper and brass cathodes are decreased from 63.80 to 1.8 µm and 0.98 µm, which corresponds to improvement rates of approximately 97% and 98.4%, respectively. Experimental results also showed that the chemical composition and microstructure of the hot isostatic pressed (HIPed) γ-TiAl cause unexpected results for copper. Heterogonous distribution of aluminum in the built layer effects the MRR and surface roughness. Layer peaks are not removed efficiently at low electrolyte conductivity values and oxide layer formation is observed in the valley that caused high surface roughness. Brighter surface is observed at highest electrolyte conductivity due to the removed oxide layer. Surface texture is examined with scanning electron microscope (SEM). In addition, as the formation of oxide layers was prevented, micropores were detected on the surface. [ABSTRACT FROM AUTHOR]

Electrochemical machining (ECM) is widely applied to manufacture parts with complex geometries, used in electronic components and the automotive, military, and aeronautics industries. These parts have a surface shaped by controlled anodic dissolution at high current density levels, using a neutral solution of inorganic salts (i.e., NaCl or NaNO3) as the electrolyte. Such conditions generate a high amount of sludge that deposits onto the surfaces of equipment, devices, cathodes, and working pieces, requiring daily and complicated sludge management during the series production in the industry. Thus, the main goal of the present work is to propose a simple way to reduce sludge generation in the ECM industrial process. To do so, complexing (EDTA) or reducing (ascorbic acid) agents were added to the electrolyte composition, creating parallel reactions to keep the metallic ions from precipitating. The complexing agent EDTA resulted in a 30% reduction in sludge mass, using an alkaline solution (pH > 10.0). The reducing agent, ascorbic acid, resulted in a 90% reduction in sludge mass, using an acidic solution (pH < 5.0). This sludge reduction has the potential to contribute significantly to increasing equipment, devices, and cathode lifetime, as well as reducing costs associated with centrifuge or filter maintenance (sludge removal from electrolyte) and increasing the productivity of industrial ECM processes. [ABSTRACT FROM AUTHOR]

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Manufacturing processes are becoming increasingly data-driven. Integrating manufacturing data and process models in real-time, a digital twin (DT) may function as an autonomous and dynamic digital replica. This, in turn, may enable manufacturers to not only understand and monitor a process but also proactively control it in real-time or a product over its life cycle. This paper examines the DT concept and its evolution and presents a future DT framework. DTs' key components (e.g., process models) and implementation are focused on additive manufacturing, electrical discharge machining, and electrochemical machining. Furthermore, current challenges and future research directions are summarized. [ABSTRACT FROM AUTHOR]

Bulk nanostructured metals and alloys are finding increasing structural applications due to their superior mechanical properties. The methods that rely on the severe plastic deformation technique for effecting microstructural refinement through imposing large strains are utilized mostly to produce nanostructured materials. The machining process has been demonstrated as a simple process for severe plastic deformation by imposing large strains through a single pass of the cutting tool where strains in a range of 1–15 can be imposed for a variety of materials by varying the cutting conditions and tool geometry. However, the geometry of the resulting chip subjected to severe plastic deformation during the machining process is not under control and, hence, a variant of the machining process, called the large-strain-extrusion machining process, has been proposed and utilized extensively for producing bulk nanostructured materials. Large-strain-extrusion machining possesses simultaneous control over microstructure refinement, through managing the strain during large-strain machining, and the shape and dimension of the resulting chip by the extrusion process. This study provides a comprehensive review of the large-strain-extrusion machining process by presenting the findings related to the utilization of this process for the production of fine-grained foils for various metals and alloys. Further research efforts related to finite-element modelling of large-strain-extrusion machining and their usefulness in designing the experimental setup and process conditions are also discussed. [ABSTRACT FROM AUTHOR]

α – β titanium alloy (Ti-6Al-4V) is being used in diverse applications, such as aircraft, chemical, automotive, and biomedical industries due to its excellent attractive properties. But machining of titanium and its alloy is a tedious task through conventional material removal processes. Removing the material at the micro level to create micro-sized features like a hole, slot and intricate projection in the titanium alloy is more complicated. In this paper, micro-sized through-hole machining on the α – β titanium alloy has been performed using electrochemical micro-machining (EC μ M) with nonaqueous ethylene glycol (CH2OH)2–sodium bromide (NaBr) electrolyte and the influence of machining parameters, such as electrolyte concentration (EC), machining voltage (MV), tool feed rate (TFR) and duty cycle (DC) during micro-hole machining on the α – β titanium alloy is analyzed. The material removal rate (MRR), radial overcut (ROC), conicity (C), and surface roughness (SR) of the micro-sized through hole have been ascertained and analyzed. The selected machining parameters are optimized using Taguchi based Grey relation analysis and DEAR methods. [ABSTRACT FROM AUTHOR]

• The effect of clamping deformation on the material removal amount and cyclic material removal process on the residual stress are determined. • Energy equations under three-dimensional non-uniform residual stress field are established. • Excellent agreements of the machined surface shapes are obtained for predicted and experimental results. • The influence of cutting parameters and strategies on machining deformation is anlyzed. • The evolution of machining deformation in process is investigated. Workpiece deformation under the coupling effect of clamping force, initial residual stress (IRS), and machining residual stress (MRS) is an essential concern in the manufacturing of thin-walled metallic parts. Prediction of machining deformations is critical for ensuring machining quality and has significant guiding implications for producing thin-walled parts. However, most research has been focused on calculating machining deformation caused by a single factor. Based on the energy principle, the effect of clamping deformation on the material removal amount and the effect of the cyclic material removal process on both IRS and MRS are analyzed. To predict the machining deformation of circular metallic plates, energy functions under the three-dimensional non-uniform residual stress field consider the coupling effect of multiple factors, which is established and solved by the Rayleigh-Ritz method. This analysis elucidates the formation mechanism of machining deformation under the single-factor effects of IRS and MRS as well as the coupling effect of clamping force and residual stress. In this article, an analytical prediction model with a prediction error of around 8.5% is established for machining deformation under the coupling effect. Additionally, leveraging the quantitative results of the proposed model, the impacts of cutting parameters and strategies on machining deformation, as well as the evolution of machining deformation throughout the entire material removal process are elicited. [ABSTRACT FROM AUTHOR]

The growing need for more energy efficient systems has led to advent of hard and corrosion resistant materials which are difficult to machine with both conventional and non-conventional machining techniques. Although ECM offers athermal and force-free dissolution, the workpiece surface integrity in multicomponent materials is limited with ECM due to several multi-physical phenomena occurring on the surface like selective phase dissolution, passivation, pitting, particle breakout, etc. To tackle these challenges, aggressive acidic and basic reagents are added to the electrolytes. Although these reagents improve the machining performance, they are not sustainable for the environment and human life as they generate harmful waste which is difficult to dispose and recycle. Furthermore, the handling of these aggressive electrolytes requires specialized coatings, resins, filters, catalysts, etc. to protect the machine tools and equipment from damage. Hybrid laser-ECM (LECM) is a relatively novel drill-mill processing technique to process these advanced materials while using neutral electrolytes, thereby potentially reducing the negative impact of using acidic/basic reagents in electrolytes. Under controlled conditions and proper laser alignment, LECM can simultaneously apply laser and EC process energies in the same machining zone to provide synergistic benefits manifesting in terms of dominance of kinetics and thermodynamics over pure electrodynamics in ECM. This provides multi-fold benefits in improving passivation weakening and homogenize multiphase dissolution. Therefore, this study investigates for the first time the machining performance, removal behaviour, reaction products and power/resource consumption of LECM in neutral electrolyte in comparison to ECM in various neutral and basic electrolytes. The NbC–Ni cermet was used as the workpiece material, which is a cobalt-free alternative to conventional WC-Co. The results revealed that LECM in neutral NaNO 3 compared to ECM with NaOH addition not only provided better Sa (2.02 μm, 24% ↓), M.R.R. (153 μg/s, 31% ↑), aspect ratio (0.048, 14% ↑) and similar passivation weakening capability while maintaining a nearly neutral pH (8) of the reaction products, but also reduced electrolyte usage by 23.6% with a 16.4% increase in power consumption. These aspects make LECM a sustainable and cost-effective candidate for processing modern passivating multiphase materials like newer cermets, super alloys, high entropy alloys, etc. with nearly same performance as achieved by using ECM with acidic/basic electrolytes. Further fundamental and applied research is needed in LECM to meet the industrial specifications. [Display omitted] • LECM in neutral electrolyte provides sustainable, precise and productive machining comparable to ECM with aggressive electrolytes. • Machinability of NbC–Ni cermet is investigated as potential alternative to cermets with carcinogenic Co binder. • Material removal characteristics of NbC–Ni cermet with ECM/LECM are analysed. • Power and resource consumption, and environmental impact of LECM and ECM are reported. • LECM enhances processing benefits in sustainable way with marginal additional power consumption. [ABSTRACT FROM AUTHOR]

Electrochemical machining (ECM) is a non-contact and athermal machining process where the material removal is accomplished through controlled anodic dissolution of the workpiece governed by Faraday laws. ECM process has been hybridized with several other processes for improving material processing windows. Hybrid laser electrochemical machining (LECM) synergistically applies electrochemical and laser process energies with added benefits of escalated reaction kinetics leading to enhanced transpassive dissolution, weakening of passivation layer, process localisation and uniform dissolution. The laser energy acts as a localised and controllable heat source thereby offering multi-fold processing benefits. For alloys and cermets, a characteristic surficial fingerprint is the presence of inhomogeneous multiphase dissolution and sporadically distributed passivation layer, necessitating addition of aggressive reagents in electrolytes. LECM has the potential to addresses these challenges while processing in pH neutral electrolytes. Previous works have very limited analysis on the macro and micro removal mechanisms while processing relevant strategic materials and multitude of applications of LECM remain unexploited. Therefore, this work presents in-depth investigations into macro and micro-scale material removal mechanisms of ECM/LECM on sintered niobium carbide with nickel binder (NbC–Ni), which is a potential cobalt-free alternative to tungsten carbide. The results revealed new insights into the removal behaviour of the constituent phases which differed from the first principles and their interaction with the laser. During ECM, the Ni phase dissolved preferentially and influenced the surface pattern and particle breakout which was reduced with laser assistance. The surface evolution characteristics were also analysed based on the ridge-crevice pattern. Additionally, the weakening of passive layer was correlated with the pulse analysis that revealed quantitatively the different process regimes occurring during ECM and LECM. The grain level study revealed that orientation effects still exist during LECM and the grains with higher surface energy (FCC (001) vicinal planes) passivated more and dissolved less. Furthermore, the improvement in surface quality, overcut and reduction in particle breakout with LECM process makes it promising for machining newer recipes of metal carbides. [Display omitted] • The in-depth macro and micro-scale hybrid removal mechanisms of NbC–Ni during ECM and LECM are firstly reported. • Analysis of passivation weakening, multiphase dissolution and particle breakout with ECM and LECM revealed new insights. • A current pulse analysis framework was utilised to identify different process regimes during ECM and LECM of NbC–Ni. • Comprehensive hybrid material removal mechanisms for NbC–Ni during ECM and LECM are proposed with supporting results. • Knowledge transferability to similar material systems is proposed. [ABSTRACT FROM AUTHOR]

Electrochemical Discharge Machining process applied for machining of both electrically conducting and non-conducting materials. It became crucial to measure the material removal rate while processing of advanced materials. This paper deals with comparison of optimization of MRR by different techniques like Taguchi method, RSM, PSO and ANN during µ-profile generation on glass material using µ-ECDM process. The experiments were conducted using the combinations of three input parameters such as voltage, electrolyte concentration and pulse frequency based on different experimental design. Increase in voltage and electrolyte concentration results in MRR increase, but with increase in pulse frequency MRR decreases. Optimal value of MRR along with the parametric combinations using all four techniques has been derived and compared. [ABSTRACT FROM AUTHOR]

Abstract Electrochemical machining (ECM) is a process that is widely employed to machine extremely hard materials. However, because of the fluidity of the liquid electrolytes used in conventional ECM, it is difficult to accurately limit the electrolyte distribution over the machining area to prevent the occurrence of stray-current corrosion. Therefore, in this study, to overcome this shortcoming, a non-conductive solid porous ball is used as an electrolyte absorption material in ECM. The electrolyte is absorbed by the porous structure of the ball, and an electrolyte film is formed on the ball surface generating current paths from the workpiece to the tool electrode while preventing the electrolyte from flowing freely in an undesired manner over the workpiece surface. Because the workpiece is not immersed in the electrolyte, only the area in contact with the electrolyte held in the porous ball is subjected to ECM, whereas the other areas of the workpiece remain unaffected. In this way, the electrolyte distribution is limited to the desired area. In this paper, a newly developed experimental procedure, its machining mechanisms, and applications are explained. In addition, several unsolved problems that occurred in the experiments are reported and discussed. • The machining mechanism, features, and applications of ECM using electrolyte absorbed in solid porous ball are investigated and discussed. • To control the electrolyte distribution, a solid porous material was used as the electrolyte absorption material in ECM processing. • To better understand the machining characteristics of this method, a number of the factors influencing these characteristics are examined experimentally. [ABSTRACT FROM AUTHOR]

Wire Electric Discharge Machining (WEDM) is a non-traditional machining method that is widely used in the manufacture of aerospace/aircraft and medical equipment for conductive materials. WEDM products are expected to have good dimensional accuracy, surface roughness, and geometry. Many researchers have done experiments on various materials to optimize the process, which has many parameters and response characteristics. This paper provides an overview of the WEDM process on alloy steels in order to understand the impact of input process variables on output responses and optimization techniques for selecting optimal process parameters. This paper also highlights WEDM process trends as well as workpiece materials, wire varieties, wire diameters, and optimization approaches. This work is expected to be useful in initiating further research on WEDM by documenting substantial research works confirming the latest scenario. [ABSTRACT FROM AUTHOR]

The paper deals with the classification, applications, and advantages of microelectromechanical systems (MEMS), materials, and technologies used. This area of production represents one of the most promising technologies of 21st century, with a big impact in manufacturing 4.0. Nowadays, MEMS fabrication methods have a very big influence in the area of medicine, and therefore the review applications of utmost importance like micromechanical stents or antenna stents are related. The study presents information about MEMS based micro‐EDM, regarding working parameters and some examples of techniques used to realize MEMS devices. These have the purpose to minimize the cost together with the increase of the output technological parameters. The process capabilities of micro‐ECM, associated with working parameters are also treated, and the potential applications in industries like automotive, aerospace, biomedical, security, communication, etc. Finally, some future challenges of MEMS application in the specified fields are exposed. [ABSTRACT FROM AUTHOR]

Electrochemical machining (ECM) is a method for removing metal by anodic dissolution. At the interface between the workpiece surface and an electrically conductive fluid (electrolyte), the material is dissolved locally without direct physical contact to the cathodic tool. Due to the force‐free nature of the process, ECM is used for machining high‐strength or hard materials, such as titanium aluminides, Inconel, Waspaloy, and high nickel, cobalt, and rhenium alloys. However, determining suitable process parameters remains challenging due to their interacting effects on working distances during the machining process. Therefore a simulation‐based approach to process design substantially reduces resource and time investment to achieve the desired geometry of the finished part. This methodology requires data about the materials electrochemical properties, such as removal velocity and current efficiency, which have to be obtained experimentally. In this study, a methodology for acquiring and processing this data as well as the development of multiphysics simulation models is presented exemplarily for manufacturing a centrifugal impeller with a diameter of 14 mm consisting of the nickel alloy Inconel 713C for use in turbomachinery. [ABSTRACT FROM AUTHOR]

There is a general separation between the manufacturing processes that add value to materials on the factory floor and the techniques engineers use in the laboratory to evaluate the microstructures and the surface integrity that results. These techniques are often destructive or require a vacuum and are incompatible with production lines. However, this information has intrinsic value and could be exploited to inform production decisions during manufacture. In this study, a novel approach to acquire this information is presented that is underpinned by electrolyte jet machine tool coupled with optical microscopy, which can allow the extraction of both grain-wise partial orientation and morphological information, and crystallographic macro textures in three dimensions. Here, iterative sections are precisely machined into the near surface of a commercially pure titanium alloy using an electrochemical jet and subsequently imaged, allowing the reconstruction of high-fidelity microstructure models rapidly and under ambient conditions. In doing so, new insights into the specific orientation-dependent dissolution mechanisms are offered, and the acquisition of appropriate conditions that result in nanoscale roughness surfaces (avoiding the dominance of pitting and preferential grain removal) is firstly explored. Building on prior work, a piecewise approach is presented to analyse the acquired image stacks to map partial crystal orientations, while different approaches are proposed to account for jet-specific surface artefacts and waviness. This is repeated over 20 layers in an individual specimen and layer-wise orientation maps are used to construct volumetric models of the specimen. These data sets are then explored from the perspective of materials/manufacturing engineers, who may use to this information to effect advancements to materials processing technologies. [Display omitted] • An electrolyte jet can be used as a rapid, ambient, and low-cost serial sectioning tool to map microstructures in 3D. • Surface generation mechanisms explored in Ti CP 1, allowing insight into stable process parameters for surface imaging. • Process stability was demonstrated by 20 repeated sections at a layer resolution of 1.8 μm allowing grain reconstruction. • Partial orientations were extracted from polarized light images, allowing observation of grain interfaces from 3D datasets. [ABSTRACT FROM AUTHOR]

Electrochemical Discharge Machining (ECDM) has combined characteristics of ECM and EDM which is effectively been used for machining electrically nonconductive, hard, and brittle materials like glass, quartz, and ceramics. However, the industrial application of this process is limited due to difficulty in machining micro holes with higher machined depth. To improve the machining performance of the ECDM process, loose abrasive particles have been mixed in an electrolyte while machining blind holes on soda–lime glass. This study is mainly focused on investigating the effect of process parameters (voltage and electrolyte concentration) on the responses (volume of material removed, machined depth and overcut) using CCRD. The significance of process parameters on the responses has been evaluated using ANOVA. A second-order regression equation has been developed for predicting the relation between input process parameters and quality characteristics (i.e. volume of material removed, diameter overcut, and machined depth). It is observed that the addition of Al2O3 abrasives has improved the volume of material removed and machined depth. On the other hand, the addition of SiC abrasives into the electrolyte has reduced the diametric overcut due to their specific characteristic. [ABSTRACT FROM AUTHOR]

Micro-electrochemical machining (micro-ECM) has been widely used for microscale and nanoscale processing of materials. The performance of the nanosecond pulse power supply is directly related to the precision of micro-ECM, which is one of the core technologies for micro-ECM. In this work, a nanosecond pulse power supply, with adjustable pulse frequency, duty cycle, and voltage, was designed with an STM32F103VET6 single-chip microcomputer as the control core and a metal–oxide–semiconductor field-effect transistor as the chopper switch component. The performance test has shown that the power supply can produce a continuous pulse with the highest frequency of 8 MHz, the shortest pulse width of 50 ns, the maximum peak current of 12 A, and the maximum voltage of 10 V. As compared with the power supply reported in the literature, the present power supply demonstrated the enhanced output current and improved waveform of the nanosecond pulse output, which could result in better machining accuracy and efficiency for micro-ECM. [ABSTRACT FROM AUTHOR]

Applying different micro-bits with different sizes to carry out step-by-step drilling is a common technique to obtain micro-stepped holes. However, the possibility of repeated misalignments in the clamping of micro-bits will affect the machining accuracy of the micro-stepped holes. Furthermore, for difficult processing materials such as die steel and cemented carbide, it is difficult to obtain ideal machining results through drilling. Under this background, micro-stepped hole was processed on die steel based on the electrical discharge machining (EDM) wear of micro-bits. Firstly, a high-speed rotating micro-bit was used to perform micro-EDM on die steel to obtain a basic micro-hole. During the micro-EDM process, the micro-bit was worn and thus its length was reduced. Secondly, the worn micro-bit shook along a defined axis to carry out micro-EDM on the die steel workpiece, thus machining micro-stepped hole on the basic micro-hole. This method avoided the clamping error of micro-bit found in other techniques and improved machining accuracy of micro-stepped hole. Through the analysis of variance (ANOVA) of processing parameters and the establishment of surface response model, the appropriate processing parameters were selected. Finally, under the action of appropriate processing parameters, micro-stepped hole was obtained by the proposed method. [ABSTRACT FROM AUTHOR]

Short glass fiber composites, particularly sheet molding compound (SMC) materials, are becoming increasingly important alternative in various contemporary aerospace, automotive, and electronic applications. For these manufacturing industries, the quality of the machined SMC composite is still a challenging target. The article proposes a new tool design with an offset between teeth to minimize friction, limit damage and promote chip removal when drilling composite materials. The effects of the tool's geometric parameters, especially the rake, the inclination and the complementary side cutting edge angles on the material removal process, as well as the cutting and thrust forces, are investigated. A 3D finite element model of a representative multi-tooth tool is developed using the ABAQUS\Explicit code. The results show that fine-tuning the geometric parameters of the tool reduces the induced machining damage and enhances the chip removal and the flow evolution. The rake angle has a significant influence on the cutting and thrust forces. However, both forces are insensitive to the inclination angle. The complementary side cutting edge angle influences only the thrust force. The presented outcomes not only give insights into the cutting process, but also improve the SMC machinability. [ABSTRACT FROM AUTHOR]

Nontraditional manufacturing processes (NTMPs) bring the processing capabilities such as machining high strength and hard materials with desired accuracies and surface finish to the manufacturing companies. Therefore, there has been a significant increase in the use and number of NTMPs. Hence, choosing a particular NTMP for a specific application turns out to be a complex decision-making problem, which involves conflicting qualitative and quantitative ranking criteria. In recent NTMP ranking literature, it is noted that fuzzy approaches are better suited for handling uncertainties and incomplete information that exist within the NTMP ranking environment. This paper introduces such a fuzzy approach using the hesitant fuzzy preference selection index (PSI) method for the assessment of the criteria weights and the hesitant fuzzy correlation coefficient principle for ranking and recommending the most appropriate NTMP for a specific application. The proposed methodology and its efficiency in dealing with incomplete information under the fuzzy decision-making environment are explored with a case study. As a result of the study, the proposed model preferred the electron beam machining (EBM) as the most suitable nontraditional manufacturing process. On the other hand, triangular fuzzy TOPSIS methods offered the electrochemical machining (ECM) as the best choice among the alternatives. The differences among the ranking decisions are also analyzed in the paper. It can be concluded from the authors' various applications of the proposed hesitant fuzzy PSI method that it is extremely effective in representing fuzzy decision-making environments in NTMP ranking decisions. [ABSTRACT FROM AUTHOR]

Especially for slicing hard and brittle materials, wire sawing with electroplated diamond wires is widely used since it combines a high surface quality with a minimum kerf loss. Furthermore, it allows a high productivity by machining multiple workpieces simultaneously. During the machining operation, the wire/workpiece interaction and thus the material removal conditions with the resulting workpiece quality are determined by the material properties and the process and tool parameters. However, applied to machining of carbon fibre reinforced polymers (CFRP), the process complexity potentially increases due to the anisotropic material properties, the elastic spring back potential of the material, and the distinct mechanical wear due to the highly abrasive carbon fibres. Therefore, this experimental study analyses different combinations of influencing factors with respect to process forces, workpiece surface temperatures at the wire entrance, and the surface quality in wire sawing unidirectional CFRP material. As main influencing factors, the cutting and feed speeds, the density of diamond grains on the wire, the workpiece thickness, and the fibre orientation of the CFRP material are analysed and discussed. For the tested parameter settings, it is found that while the influence of the grain density is negligible, workpiece thickness, cutting and feed speeds affect the process substantially. In addition, higher process forces and workpiece surface temperatures do not necessarily deteriorate the surface quality. [ABSTRACT FROM AUTHOR]

Electrochemical machining relies on the electrolysis phenomenon, this being characterized by the chemical reaction between the workpiece material and an electrolyte solution. Both the electrode and the workpiece materials are connected into an electric circuit, charged by a direct current electric energy source. The workpiece is used to get some complex forms of cavities into parts of electrically conductive materials or other hard conductive materials, which could not be processed efficiently by the other means. This paper presents the results of some research related to the development of an equipment concept that could highlight the variation of some output parameters of the process in function of the value of the input factors in the process. It has opted to create a device for studying electrochemical erosion, where different substances, with a direct current source with variable adjustment. Taking into account the experimental results when using different materials for the workpiece, different materials for the tool electrode, many working electrolyte type substances, and changing the values of the electrical parameters, results necessary for a relevant conclusion could be obtained. [ABSTRACT FROM AUTHOR]

Electrochemical discharge machining (ECDM) can be applied as a non-traditional processing technology for machining non-conductive materials such as glass and ceramics, based on the phenomena of evoked electrochemical discharges around the tool electrode. The material removal mechanism of ECDM is noticeably complex and difficult to experimentally characterize. In this paper, finite element models were proposed to predict the material removal in the ECDM discharge regime. First, the single-pulse discharge on a tapered electrode was modeled. It was found that about 30.5% of the discharge energy is transferred to the workpiece. The continuous discharge on a cylindrical electrode was thereafter modeled according to this phenomenon, in which the removal of a layer of the workpiece material starts from the projected contour of the edge of the electrode end and extends inward during the ECDM processing. The effective discharge ratio for material removal was calculated to be 10.1%. The drilling depths of holes at different applied voltages were predicted by the proposed finite element method. It was found that the predicted values were consistent with the experimental results. • The fraction of discharge energy transferred to the workpiece was found to be 30.5% in ECDM. • The material removal expands inward from the projected contour of the electrode edge. • The effective discharge rate was found to be 10.1% in ECDM. [ABSTRACT FROM AUTHOR]

Although ceramic materials are known for their high-temperature stability, high hardness, high strength-to-weight ratio, and high resistivity to wear, their inherent brittleness makes them difficult to machine. Electrical discharge machining (EDM) is a noncontact machining process that can machine any workpiece irrespective of its hardness, as long as the material is electrically conductive. Therefore, the challenge that comes with the EDM of ceramics is the electrical nonconductivity. This study has focused on implementing and modifying assisted electrode method to machine aluminum nitride (AlN) ceramics by the EDM process with a goal of machining through holes. A successful sandwich structured multilayer removable coating assistive electrode method has been developed, and the effectiveness of assistive electrode in the material removal process has been investigated from experimental and theoretical perspectives. A physics-based model has been proposed to understand the material removal mechanism and how the proposed assistive electrode can lead to successful machining in electrically nonconductive ceramics. Melting and thermal spalling have been identified as dominant forms of material removal during EDM of nonconductive ceramics. The amount of carbon deposition on the walls of the machined surface is a key parameter that dictates the feasibility and outcome of the method. Deposition of carbon introduces electrical conductivity to the machining zone that allows machining to go through. According to the model, plasma channel radius is reduced due to the low conductivity of the workpiece, which aids in concentrated energy transfer from electrode to workpiece. In addition, the maximum heat flux generated for a particular peak current also decreases with the increment of pulse-on time. The proposed physics-based model was found to be effective in predicting the performance of assistive electrode for EDM of ceramics. [ABSTRACT FROM AUTHOR]

The growing dominance in terms of industrial applications has helped polymer‐based composite materials in conquering new markets relentlessly. But the presence of fibrous residuals and abrasive particles as reinforcement in polymer matrix composites (PMCs) affects the output quality characteristics (OQCs) of microdrilling operations. The OQC aims at reducing overcuts and momentous material removal rate (MRR). In such perception, multi‐objective particle swarm optimization (MOPSO) evident to be a suitable optimization technique for prediction and process selection in manufacturing industries. The present paper focuses on multi‐objective optimization of electrochemical discharge drilling parameters during drilling of SiCp and glass fiber‐reinforced PMCs using MOPSO. The response surface methodology (RSM)‐based central composite design was used for the experiment planning. Electrolyte concentration, interelectrode gap, duty factor, and voltage were used as process parameters, whereas MRR and overcut were observed as OQCs. The obtained experimental results were initially optimized by RSM‐based desirability function and later with multiresponse optimization technique MOPSO to achieve best possible MRR with lower possible overcut. The comparative analysis proves that OQCs can be effectively improved by using MOPSO. [ABSTRACT FROM AUTHOR]

High precision and clos tolerance is an essential requirement of current manufacturing industries dealing in micro-fabrication. The quality of surface obtained after machining process exhibits the utility of product. The various material and alloys are developed continuously to fulfill the need of application in critical conditions. The versatile characteristics of material also required a modification in manufacturing processes. The exotic material required a special treatment of machining to avoid the failure. Various methods of conventional, un-conventional and their hybrids have been developed to meet the above requirement. Wherein, ultrasonic vibration assistance has been extensively applied in numerous manufacturing processes to increase the process performance. In present review, ultrasonic vibration (UV)-assisted manufacturing processes for machining/finishing are covered using selected materials. Additionally, the benefits of UV assistance in welding such as arc compression, plasma pressure are discussed in details. Moreover, assistance of vibration in non-traditional machining processes such as ECM, EDM and AWJM is discussed in detail with their effects. In machining, ultrasonic assistance facilitate basic process by reduction in cutting force, and improvement in the machined morphology. Thus, the outcomes obtained from the large number of published literatures strongly demonstrate the significance of ultrasonic vibration in various sections of present article. [ABSTRACT FROM AUTHOR]

In the present study we established for the "Nonconventional Technologies" research field, the composition of a keyword vector (terms specific to the analyzed field) = {advanced materials, electrical-discharge machining, hybrid machining, electrochemical machining, micro EDM, micro-ECM, hybrid ultrasonic machining} to carry out a research based on two main directions/components. The first component consists in the process of identifying the works that address the specific terms in the composition of the above vector in Web of Science. The second component is the analysis of the interest of Google users, in searches based on the keyword vector. The emergence, development and diversification of the technologies that make up the keyword vector in this paper is mainly due to their use in the processes of advanced materials machining. The importance, and the key role played by advanced materials and technologies is emphasized by utmost personalities from the academic, research and industry fields. [ABSTRACT FROM AUTHOR]

The support platform is an essential component of a hydrogenation reactor, providing stable support for internal components and ensuring efficient reactions. However, the manufacturing method of overlay welding and complex structure of support platform unavoidably generates welding residual stresses (WRS) and stress concentration, posing a threat to operational reliability. In this paper, the WRS distribution and cracking causes of the support platform of hydrogenation reactor was studied by the finite element method (FEM) combined with experimental research. Four manufacturing processes for the support platform were compared in terms of their residual stresses, and the influence of welding heat input and fillet size on the WRS was discussed. The results indicate that the abrupt increase in residual stresses at the fillet region following the machining of the base layer has enhanced the likelihood of crack occurrence. The cumulative effect of stress concentration resulting from improper welding processes and structural discontinuities, along with the tensile stress during normal operating conditions, renders the surface layers susceptible to cracking during service. The manufacturing process significantly influences the distribution of residual stresses. To obtain a reliable and crack-resistant large-sized hydrogenation reactor support platform, a welding procedure with a certain machining allowance at the support platform location prior to overlay welding should be adopted. The fillet size has a notable effect on the residual stresses at the fillet region of transition layer. Recommended fillet sizes are 15 mm radius for the base layer, 11 mm radius for the transition layer, and 8 mm radius for the surface layer. Additionally, the heat input greatly affects the hoop stresses in the transition layer, in order to avoid the occurrence of cracks, a recommended heat input of approximately 20 kJ/cm is suggested. • Residual stress distribution and crack causes of the support platform were analyzed. • Surface layer fillet is more prone to cracking. • Manufacturing with a machining allowance as the root has optimal stress distribution. • Increasing fillet size significantly reduces residual stress of transition layer. [ABSTRACT FROM AUTHOR]

Electrochemical discharge machining (ECDM) has been developed as a hybrid and robust technology for machining non-conductive work material at a preferable removal rate. ECDM exhibits various applications in the micro-machining of these materials like nuclear, automotive, medical industries, etc. Due to some peculiar properties of nonconductive materials, for example, glass transparency, their utilization in MEMS applications are also very numerous. In the ECDM process, removal of material takes place primarily due to high-temperature thermal erosion and secondarily due to electrolyte chemical etching action. Many rigorous experimental studies have reported in the empirical estimation of the material removal rate (MRR) in the ECDM process. However, very few studies have reported in the modeling of the ECDM process for predicting material removal rate through single spark simulation. The present paper attempts to develop a transient thermal model based upon finite element modeling (FEM) to simulate a single spark in the ECDM process for obtaining temperature fields in the work material. The obtained temperature fields are further post-processed to predict the material removal rate. FEM results are compared with the previous simulated and experimental results to confirm the approach. Moreover, an experimental study is also performed to validate the developed thermal model and it was found to be in an acceptable range of the experimental results. Further, a parametric study revealed that MRR increases with the increase in applied voltage and electrolyte concentration during soda-lime glass machining with ECDM. The developed FEM-based transient thermal model can be successfully utilized for predicting the removal rate of nonconductive work material. [ABSTRACT FROM AUTHOR]

Hybrid laser-electrochemical micromachining is a fast and force-free processing technique to machine difficult-to-cut multimaterials with conductivity variations and has the advantage of accelerated material dissolution, oxide layer weakening and surface quality. In this process, the laser can assist electrochemical dissolution or participate in material removal depending on the fluence available on the workpiece surface. The tool-based configuration allows delivery of laser and ECM at higher machining depths and achieves homogeneous application of the two aforementioned processes. The combination of laser and ECM results in high material removal, better surface integrity and processing of advanced materials. On passivating materials, the oxide formation is weakened. In this research, a multidisciplinary model scheme is proposed using a global modelling approach where the model mimics several microscopic physical and chemical phenomena involved in this tool-based hybrid laser-ECM process. The model takes into account electric currents, fluid dynamics, modelling of laser source, hydrogen and oxygen gas generation and heat transfer in solids and fluids. The model allows to study temperature effects on each of the phenomena in the model. Material removal is simulated by using a deformed geometry feature and an automatic remeshing technique generates a new boundary for each subsequent solution step on Comsol® multiphysics platform. The multiphysics model is presented in detail with a brief description and intuitive explanation of each physics module. The proposed multidisciplinary model scheme can improve the physical understanding of the hybrid laser-ECM process as well as assist in process design for specific applications. The model allows to predict the machined profiles and current density distribution simultaneously. This model also provides insights into several multiphysics phenomena occurring in the interelectrode gap which are difficult to characterize experimentally and therefore the model can act as a virtual sensor. In the later sections of this paper, model based findings are supported experimentally. [ABSTRACT FROM AUTHOR]