ECDM Process Research Articles

Effect of discharge thermal action in ECDM on electrochemical behaviours of matrix material and its recast layer in glycol-based solution

The interaction between thermal and electrochemical corrosion in the ECDM process remains unclear. This study clarifies the effect of discharge thermal action on electrochemical corrosion. Real-time temperature curves indicate that the solution temperature in the electrochemical corrosion zone increased significantly due to discharge thermal action. The corrosion resistance of the recast layer’s passive film is superior to that of the matrix due to the enrichment of Cr2O3. As the electrolyte temperature rises, the passive film thickens but shows lower polarization resistances and poorer corrosion resistance due to a loose and weak structure. The matrix material and its recast layer dissolved uniformly, resulting in a considerably flat surface in a glycol-based solution, with enhanced levelling efficiency due to discharge thermal action.

On process stability and sustainability of controlled-Electro Chemical Discharge Machining (ECDM)

ABSTRACT To mitigate the transmission losses, glass vias have the potential to replace silicon vias in wireless transmission systems. In the wake of limitations of the existing methods, ECDM is an evolving process for glass micro drilling. However, the process control of ECDM is compromised due to variation in electrolytic conditions in terms of concentration and temperature. As a result, poor stability and sustainability hampers the commercial viability of the ECDM process. Therefore, present communication attempted to enhance the stability and sustainability of the ECDM with a novel approach and termed as controlled-ECDM. Subsequently, the process stability (real time based) of the controlled-ECDM has been compared with basic-ECDM using the user’s preference rating and I-MR chart. The results indicated a 20.65% gain in overall stability by controlled-ECDM. Additionally, the assessment of electrolyte emissions and performance on the radar graph indicated an improvement in the sustainability of the process.

Enhancing the borosilicate glass micromachining by using mixed alkaline electrolytes in the ECDM process

ABSTRACT This article investigates the effects of mixing different alkaline electrolytes on the geometrical features created by the ECDM. Sodium hydroxide (NaOH) and potassium hydroxide (KOH) were mixed in varying volumetric proportions. Effect of critical process parameters on the depth and width of the microchannels and the associated tool wear was investigated. Pure NaOH electrolyte has resulted in the highest depth compared to the pure KOH electrolyte. Process mechanism behind the role of mixed electrolytes on the opening sizes and depths of microchannels is explained. Higher material removal by the NaOH electrolyte was due to the larger number of sodium (Na+) ions in the electrolyte, resulting in more aggressive electrochemical discharge; however, it also resulted in severe tool wear. Mixed electrolytes with a KOH yielded lower width and low tool wear. Increasing the volumetric proportion of KOH in the mixed electrolyte gradually decreased the machining depth, width, and tool wear.

Microchannel Fabrication on Silica Glass and Experimental Investigation of MHD Convection in ECDM Process

Microchannel Fabrication on Silica Glass and Experimental Investigation of MHD Convection in ECDM Process

Experimental investigation and comparative study between machining of CFRP composite and CNT-mixed CFRP composite using ECDM process

Experimental investigation and comparative study between machining of CFRP composite and CNT-mixed CFRP composite using ECDM process

Hybridization of μ-electrochemical discharge machining (μ-ECDM) process: A review

The Electrochemical Discharge Machining process is a non-conventional and a novel micro machining technique, which combines the advantage of ECM (chemical etching) and EDM (melting and vaporization) to machine hard, brittle and electrically non-conductive materials like glass, ceramics and composites with improved surface finish and machining rate. It is extensively used for making surface channels, microgrooves and micro-holes in glass. The necessity for hybridization of the ECDM process was triggered in order to improve the efficiency and machining performance of the process. The purpose of this article is to provide information in form of a review to readers on the existing triplex hybrid techniques of the ECDM process that is based on primary and secondary methods and its advantages have been discussed.

Simulation and experimental research of material removal rate in micro-electrochemical discharge machining process

ABSTRACT 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.

A Review on Developments in Electrolytes and their Feeding Methods for ECDM Process

A Review on Developments in Electrolytes and their Feeding Methods for ECDM Process

Finite element modeling of quartz material for analyzing material removal rate in ECDM process

Finite element modeling of quartz material for analyzing material removal rate in ECDM process

Implementation of tool and electrolyte-based development in the ultrasonic-assisted ECDM process: a review

Implementation of tool and electrolyte-based development in the ultrasonic-assisted ECDM process: a review

Neural Network (NN)-Based RSM-PSO Multiresponse Parametric Optimization of the Electro Chemical Discharge Micromachining Process During Microchannel Cutting on Silica Glass

The production of miniature parts by the electrochemical discharge micromachining process ([Formula: see text]-ECDM) draws the most of attractions into the industrial field. Parametric influences on machining depth (MD), material removal rate (MRR), and overcut (OC) have been propounded using a mixed electrolyte (NaOH:KOH- 1:1) varying concentrations (wt.%), applied voltage ([Formula: see text]), pulse on time ([Formula: see text]s), and stand-off distance (SOD) during microchannel cutting on silica glass (SiO[Formula: see text]). Analysis of variances has been analyzed to test the adequacy of the developed mathematical model and multiresponse optimization has been performed to find out maximum MD with higher material removal at lower OC using desirability function analysis as well as neural network (NN)-based Particle Swarm Optimization (PSO). The SEM analysis has been done to find unexpected debris. MD has been improved with better surface quality using a mixed electrolyte at straight polarity using a tungsten carbide (WC) cylindrical tool along with [Formula: see text], [Formula: see text], and [Formula: see text] axis movement by computer-aided subsystem and combining with the automated spring feed mechanism. PSO-ANN provides better parametric optimization results for micromachining by the ECDM process.

Effect of pulse frequency and duty cycle on electrochemical dissolution behavior of multi-tip array tool electrode for reusability in the ECDM process

Effect of pulse frequency and duty cycle on electrochemical dissolution behavior of multi-tip array tool electrode for reusability in the ECDM process

Through-holes micromachining of alumina using a combined pulse-feed approach in ECDM

ABSTRACT Micromachining of alumina has gained a lot of interest due to unique combinations of electrical resistivity and good thermal conductivity, thus being a potential substrate for microsystems packaging in high-power electronics. Creating multiple through-holes simultaneously in alumina is difficult due to its hard and brittle nature. In this article, the formation of multiple through-holes in a 425 µm thick alumina substrate is demonstrated for the first time using the combined pulse-feed approach of the ECDM process with multi-tip array tool to improve productivity. Initial experiments are conducted with a single-tip electrode to understand the effect of duty factor, pulse frequency, and feed rate. A combined pulse-feed approach is adopted to create deep microholes (>600 µm). Later, multiple through-holes are formed using 3 × 3 multi-tip array tool to achieve an average etch rate of 24 µm/min using the combined pulse-feed approach. A duty factor of 70% and a pulse frequency of 20 kHz are suggested for stable electrochemical discharge. A low feed rate (<1 µm/s) is recommended to avoid physical contact between the tool and workpiece. These multiple through-holes can be filled with electroplated copper to form 3D interconnects for upcoming radio-frequency MEMS applications.

Effect of tool-electrode material in through-hole formation using ECDM process

ABSTRACT An experimental investigation comparing the effect of tool electrode materials on the formation of microholes in glass by the pulse electrochemical discharge machining is presented. Two different materials, i.e., Molybdenum and High carbon steel (HCS), were used in the experiments carried out in 10% wt KOH electrolyte. Other parameters such as machining voltage, pulse frequency, tool feed rates were systematically varied. A lower mean discharge current was noticed when the molybdenum tool having higher electrical conductivity was used. The average reductions in the hole overcut, taper angle, and the heat-affected zone in the microholes were 30%, 55%, and 58%, respectively, when the Molybdenum tool was used compared to the HCS tool. For both tool materials, the hole overcut was measured to be minimum when a tool feed rate of 4 µm s−1 was used. The microhole diameter and heat-affected zone were increasing with the increment in the applied voltage irrespective of the tool electrode material. Due to the higher melting point, molybdenum electrodes had less tool erosion and, therefore, more suitable than the HCS tools for electrochemical discharge machining applications.

Review on Recent Advances, Research Trends, and Gas Film in Electrochemical Discharge-Based Micromachining

AbstractElectrochemical discharge machining (ECDM) is distinguished as a novel process that involves thermal heating and chemical dissolution for the micromachining of “difficult-to-machine” materials like ceramics and quartz. This paper comprehensively reviews the study on gas film, the effect of various input parameters on ECDM performance, such as electrical parameters, electrolyte parameters, and tool electrode parameters, are also likewise discussed. Moreover, a summarized report on thermal modeling, gas film, discrete input parameters, hybridization, and variants in the ECDM process is also provided in a lucid manner. Based on the review, it is concluded that the machining performance of the ECDM process especially in terms of material removal rate (MRR), roughness, tool wear (TW), and thermal cracks is strongly influenced by the input parameters. The formation of the gas film induces variable machining features that can be controlled by altering the machining conditions. Additionally, the paper highlights the future areas that may leads to improve the overall machining performance of the ECDM process.

Experimental Investigation and Analysis on Borosilicate Glass Using Electrochemical Discharge Machining Process

Electrochemical discharge machining process (ECDM) is a non-traditional machining process which has widely used in medical, electronics and aerospace industry. This paper discuss about the various different methods using same process i.e. electrode immersion depths along with electrolytic stirring effects in ECDM are discussed. The various process parameters considered during the experiment (applied voltage, electrolyte concentration and electrode immersion depths); on the other side response parameters consider as material removal, tool wear and surface finish. Experimental results indicate the adequate material removal with equivalent electrode cross sectional areas as well as fine immersion depths. Electrode immersion depth ratios, electrolyte concentration and electrolyte-stirring effect on borosilicate glass using NaOH as the electrolyte mediums show some improvement in process results. The addition of stirring effect to the electrolyte along with proper immersion depths of the electrodes resulted in improvement of the process performance mainly the improvement in surface finish values up to around four times than the normal ECDM process. The FESEM micro graphs of the fabricated micro channels reveal some interesting modes of material removal. EDS were studied for analysis of debris through this process.

Experimental investigations of energy channelization behavior in ultrasonic assisted electrochemical discharge machining

The present work analyzes the energy channelization behavior during the triplex hybrid process of ultrasonic assisted electrochemical discharge machining (UA-ECDM). In this work, a high frequency (35 kHz) low amplitude configuration of ultrasonic vibrations has been employed to investigate the ECDM process. The underlying energy channelization mechanism during the UA-ECDM process has been demonstrated while considering the evidence from high-speed imaging of gas film, discharge signals, optical images, simulation results, structural and compositional analysis of machined work material. The controlled assistance of ultrasonic in the ECDM process shifts the energy paradigm from the edges to the center of the tool electrode. Moreover, in the UA-ECDM process, the material is removed by additional cavitation and high-pressure evacuation actions along with melting, vaporization, and chemical etching phenomenon. An improved frequency of spark discharges indicates the initiation of breakdown phenomena in upward and downward strokes of ultrasonic vibrations. Energy channelization index and specific energy were taken as the performance indicators. The incorporation of ultrasonic vibrations consumed 2.23 times less energy than the ECDM process to remove a unit material per unit time. The energy channelization index with ultrasonic assistance is also improved by five times. The incorporation of ultrasonic vibrations in the ECDM process reduced the heat-affected zone and produced the machined surfaces without the alkali deficient layer. The article reports the parametric effect and their contribution to the response characteristics. The involvement of high electrochemical discharge energy with ultrasonic assistance exhibits better results in higher material removal rate and depth/diameter ratio due to the parallel provision for the evacuation of sludge/debris and electrolyte replenishment in the machining zone.

Electrochemical discharge machining process, variants and hybridization: A review

Electrochemical discharge machining has been proven to fabricate micro holes, micro-channels and three dimensional shapes on difficult to machine non conductive materials very efficiently. Researchers have proposed some modification in the basic configuration of the ECDM process to increase the efficiency. These modifications results in the development of ECDM variants. Further improvement in the process researchers hybridized the ECDM process. In this review article different areas of electrochemical discharge machining has been focused, which includes sparking phenomena, variants and recent hybridization. Furthermore, the article provides the knowledge to understand the research potential of an ECDM process.

Electrochemical Discharge Grinding of Metal Matrix Composites Using Shaped Abrasive Tools Formed by Sintered Bronze/diamond

Abstract Electrochemical discharge machining (ECDM) is a well-known process for machining of particulate reinforced metal matrix composites (MMCs). However, ECDM process suffers several drawbacks such as the lower material removal rate (MRR), high risks of tool wear rate (TWR) and relatively poor surface quality, etc. This study proposes a kind of electrochemical discharge grinding machining (ECDGM) method which employs a special shaped tool electrode. During the process, not only the can the hybrid action of electrochemical dissolution, spark erosion, and abrasive grinding improve the performance of machining MMCs, but also the special shaped of the tool electrode can be used to discharge the machined debris. And thus a higher machining efficiency and lower TWR can be obtained. The performance of developed process was conducted on machining of SiC particulate reinforced aluminum workpiece. The role of peak curre+nt, pulse duration, duty cycle, rotary speed and abrasive grit size has been investigated on MMR and TWR using the nonabrasive round electrode, abrasive round electrode, and abrasive shaped electrode respectively. The experimental results showed that using the shaped abrasive electrode for machining MMCs can achieve a higher MRR and lower TWR, as compared to the non-abrasive round electrode, abrasive round electrode. Besides, the orthogonal method was employed to analyze the relative importance of the machining parameters on MRR and TWR, it has been observed that MRR is affected by the processing parameters following the order of rotary speed &gt; peak current &gt; duty cycle &gt; pulse duration, and TWR is following the order of peak current &gt; duty cycle &gt; pulse duration &gt; rotary speed.

Micro-Hole Drilling on Ti6Al4V by Sequential Electro-Micro-Machining (SEMM) Approach

This research work explores the feasibility of drilling micro-holes on Ti6Al4V by applying a sequential electro-micro-machining process. A novel sequential combination of micro-electrochemical discharge machining ([Formula: see text]ECDM) and micro-electro-chemical machining ([Formula: see text]ECM) is applied for drilling micro-hole in titanium alloy (Ti6Al4V). The machining of titanium alloy by a [Formula: see text]ECDM process is a challenging task and not reported yet. Therefore, the feasibility of machining of Ti6Al4V by [Formula: see text]ECDM using various combinations of electrolytes has been studied. The best-suited electrolyte for drilling by [Formula: see text]ECDM was selected by analyzing the hole depth, radial overcut, hole taper angle and the minimum time required to drill through holes in a 400[Formula: see text][Formula: see text]m thick sheet of titanium alloy. The [Formula: see text]ECDM process produces micro-holes rapidly but it consists of recast layer, micro-cracks, and heat affected zone, etc. The surface characteristics of a [Formula: see text]ECDMed hole were improved by applying [Formula: see text]ECM process subsequent to the [Formula: see text]ECDM process. The sequential combination of [Formula: see text]ECDM shaping and [Formula: see text]ECM finishing results in improved dimensional accuracy, machining depth, taper angle, and surface quality of the hole produced by sequential micro-machining process.