Improvement in Micro Feature Generation in ECDM Process With Powder Mixed Electrolyte

2018 ◽  
Author(s):  
Lijo Paul ◽  
Arun B. Kumar
Keyword(s):  
Borosilicate Glass ◽  
Removal Rate ◽  
Graphite Powder ◽  
Machining Process ◽  
Duty Factor ◽  
Machined Surface ◽  
Mixed Electrolyte ◽  
Powder Concentration ◽  
Micro Holes ◽  
Tool Rotation

Electrochemical discharge machining (ECDM), also known as spark assisted chemical engraving (SACE), is an effective micro-machining process for machining of electrically nonconducting materials. It involves melting and etching process under the high electrical discharge on the electrode tip during electrolysis that enables the ECDM process to machine very hard and non-conducting materials such as borosilicate glass, quartz, ceramics etc. efficiently and economically. In the current study micro holes are machined on borosilicate glass with an electrolyte mixed with graphite powder. The conductive graphite powder in electrolyte has shown improvement in machining with more quantity of spark during machining. The main parameters taken in the study are voltage, tool rotation and duty factor along with concentration of powder in electrolyte. The main output responses taken in the study are Material Removal Rate (MRR) and lower Radial Overcut (ROC) along the machined holes. A multi-objective optimization is carried out for higher MRR and lower ROC with Grey Relation Analysis (GRA) in order to obtain the best parameters combination. From the experimental study the optimum values of parameters for MRR and ROC are found to be, voltage of 40 V, Graphite powder concentration 1.25% by weight, duty factor 70% and tool rotation of 500 rpm. From the microscopic images of the machined surface, presence graphite powder in electrolyte has improved the machined features due to its conductive nature.

Comparative evaluation of powder-mixed and ultrasonic-assisted rough die-sinking electrical discharge machining based on pulse characteristics

2019 ◽  
Vol 233 (14) ◽  
pp. 2515-2530 ◽  
Author(s):  
R Rajeswari ◽  
MS Shunmugam
Keyword(s):  
Material Removal Rate ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Graphite Powder ◽  
Machining Process ◽  
Machined Surface ◽  
Ultrasonic Assisted ◽  
Pulse On Time

Electrical discharge machining is used in the machining of complicated shapes in hardened molds and dies. In rough die-sinking stage, attempts are made to enhance material removal rate with a consequential reduction in cycle time. Powder mix and ultrasonic assistance are employed in the electrical discharge machining process to create gap conditions favoring material removal. In the present work, experiments are carried out on hardened D3 die steel using full-factorial design based on three levels of voltage, current and pulse on time. The gap phenomena in graphite powder-mixed and ultrasonic-assisted rough electrical discharge machining are studied using a detailed analysis of pulse shapes and their characteristic trains. Two new parameters, namely, energy expended over a second ( E) and performance factor ( PF) denoting the ratio of energy associated with sparks to total discharge energy, bring out gap conditions effectively. In comparison with the conventional electrical discharge machining for the selected condition, it is seen that the graphite powder mixed in the dielectric enhances the material removal rate by 20.8% with E of 215 J and PF of 0.227, while these values are 179.8 J and 0.076 for ultrasonic-assisted electrical discharge machining with marginal reduction of 3.9%. Cross-sectional images of workpieces also reveal the influence of electrical discharge machining conditions on the machined surface. The proposed approach can be extended to different powder mix and ultrasonic conditions to identify condition favoring higher material removal.

Performance of Electrical Discharge Milling and Sinking in Micro Graphite Powder Mixed Dielectric

2017 ◽  
Vol 900 ◽  
pp. 127-130 ◽  
Author(s):  
Houriyeh Marashi ◽  
Ahmed A.D. Sarhan ◽  
Ibrahem Maher ◽  
Mohd Hamdi
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Surface Hardness ◽  
High Hardness ◽  
Graphite Powder ◽  
Dielectric Fluid ◽  
Machined Surface ◽  
Performance Factors ◽  
Powder Concentration

Electrical discharge machining (EDM) is a non-conventional machining technique that is well-known for use in fabricating dies and molds owing to machinability of high hardness materials. Although the electro-thermal mechanism of EDM offers many advantages over other available machining methods, its sluggish nature limits the wide application of such machines for mass production. In this research, adding graphite powder to dielectric is proposed to improve EDM performance factors. Material removal rate (MRR) and average surface roughness (Ra) have been monitored and evaluated after addition of graphite powder to dielectric in electrical discharge milling and sinking. It is found that the presence of powder particles in dielectric fluid enhances the MRR steadily up to ~11 and ~17% for milling and sinking process, respectively. Moreover, the highest enhancement if Ra is ~31% at 1g/l graphite powder concentration for electrical discharge milling and up to ~11% for sinking process. Field emission scanning electron microscopy (FESEM) is used to inspect the machined surfaces. The surfaces machined with graphite powder mixed appear significantly unlike the surfaces machined in pure dielectric. Adding powder to dielectric is found to increase the machined surface hardness by ~26%, from 240 to 302 HV.

Optimization of μEDM process assisted with rotating magnetic pulling force and ultrasonic vibration

2021 ◽  
pp. 095440892098440
Author(s):  
Gurpreet Singh ◽  
DR Prajapati ◽  
PS Satsangi
Keyword(s):  
Ultrasonic Vibration ◽  
Material Removal Rate ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Machining Process ◽  
Micro Electrical Discharge Machining ◽  
Pulling Force ◽  
Tool Rotation

The micro-electrical discharge machining process is hindered by low material removal rate and low surface quality, which bound its capability. The assistance of ultrasonic vibration and magnetic pulling force in micro-electrical discharge machining helps to overcome this limitation and increase the stability of the machining process. In the present research, an attempt has been made on Taguchi based GRA optimization for µEDM assisted with ultrasonic vibration and magnetic pulling force while µEDM of SKD-5 die steel with the tubular copper electrode. The process parameters such as ultrasonic vibration, magnetic pulling force, tool rotation, energy and feed rate have been chosen as process variables. Material removal rate and taper of the feature have been selected as response measures. From the experimental study, it has been found that response output measures have been significantly improved by 18% as compared to non assisted µEDM. The best optimal combination of input parameters for improved performance measures were recorded as machining with ultrasonic vibration (U1), 0.25 kgf of magnetic pulling force (M1), 600 rpm of tool rotation (R2), 3.38 mJ of energy (E3) and 1.5 mm/min of Tool feed rate (F3). The confirmation trail was also carried out for the validation of the results attained by Grey Relational Analysis and confirmed that there is a substantial improvement with both assistance applied simultaneously.

Evaluation of Surface Integrity in Electrochemical Micromachining of A286 Super alloy

2021 ◽  
Author(s):  
Rajkeerthi E ◽  
Hariharan P
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Surface Integrity ◽  
Research Work ◽  
Machining Process ◽  
Electrochemical Micromachining ◽  
Dissolution Mechanism ◽  
Machined Surface ◽  
Micro Holes ◽  
Super Alloy

Abstract Surface integrity of micro components is a major concern particularly in manufacturing industries as most geometry of the products must meet out necessary surface quality requirements. Advanced machining process like electrochemical micro machining possess the capabilities to machine micro parts with best surface properties exempting them from secondary operations. In this research work, different electrolytes have been employed for producing micro holes in A286 super alloy material to achieve the best surface quality and the measurement of surface roughness and surface integrity to evaluate the machined surface is carried out. The machined micro hole provides detailed information on the geometrical features. A study of parametric analysis meant for controlling surface roughness and improvement of surface integrity has been made to find out the suitable parameters for machining. The suitability of various electrolytes with their dissolution mechanism and the influence of various electrolytes have been thoroughly studied. Among the utilized electrolytes, EG + NaNO3 electrolyte provided the best results in terms of overcut and average surface roughness.

Grinding-aided electrochemical discharge drilling in the light of electrochemistry

2018 ◽  
Vol 233 (6) ◽  
pp. 1896-1909 ◽  
Author(s):  
VG Ladeesh ◽  
R Manu
Keyword(s):  
Material Removal Rate ◽  
Borosilicate Glass ◽  
Chemical Etching ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Accuracy ◽  
Hybrid Technique ◽  
Machined Surface ◽  
Influence Of Process Parameters ◽  
Electrochemical Discharge

The electrically non-conductive materials like glass, ceramics, quartz, etc. are of great interest for many applications in modern industries. Machining them with high quality and at a faster rate is a challenging task. In this study, a novel technique called grinding aided electrochemical discharge drilling (G-ECDD) is demonstrated which uses a hollow diamond core drill as the tool for performing electrochemical discharge machining of borosilicate glass. The new hybrid technique enhances the material removal rate and machining accuracy to several folds by combining the thermal melting action of discharges and grinding action of the abrasive tool. This paper presents the experimental investigation on the material removal rate during G-ECDD of glass while using different electrolytes. An attempt has been made to explore the influence of electrolyte temperature on G-ECDD performance by maintaining the electrolyte at different temperatures. Experiments were conducted using three different electrolytes which include NaOH, KOH, and the mixture of both. The results obtained from this study revealed that an increase in temperature will favor chemical etching as well as electrochemical reaction rate. Also, it was observed that heating the electrolyte leads to an increase in the bubble density and enhances the ion mobility. This causes the formation of gas film at a faster rate and thereby improving the discharge activity. Thus, machining will be done at a faster rate. Better results are obtained while using a mixture of NaOH and KOH. From the microscopic images of the machined surface, it was observed that material removal mechanism in G-ECDD is a combination of grinding action, electrochemical discharges, and chemical etching. Response surface methodology was adopted for studying the influence of process parameters on the performance of G-ECDD. The new technique of grinding aided electrochemical discharge drilling proved its potential to machine borosilicate glass and simultaneously offers good material removal rate, repeatability, and accuracy.

scholarly journals An Experimental Study on the Precision Abrasive Machining Process of Hard and Brittle Materials with Ultraviolet-Resin Bond Diamond Abrasive Tools

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 125 ◽  
Author(s):  
Lei Guo ◽  
Xinrong Zhang ◽  
Shibin Chen ◽  
Jizhuang Hui
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Manufacturing Process ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Process ◽  
Abrasive Machining ◽  
Machining Performance ◽  
Machined Surface ◽  
Ultraviolet Curable

Ultraviolet-curable resin was introduced as a bonding agent into the fabrication process of precision abrasive machining tools in this study, aiming to deliver a rapid, flexible, economical, and environment-friendly additive manufacturing process to replace the hot press and sintering process with thermal-curable resin. A laboratory manufacturing process was established to develop an ultraviolet-curable resin bond diamond lapping plate, the machining performance of which on the ceramic workpiece was examined through a series of comparative experiments with slurry-based iron plate lapping. The machined surface roughness and weight loss of the workpieces were periodically recorded to evaluate the surface finish quality and the material removal rate. The promising results in terms of a 12% improvement in surface roughness and 25% reduction in material removal rate were obtained from the ultraviolet-curable resin plate-involved lapping process. A summarized hypothesis was drawn to describe the dynamically-balanced state of the hybrid precision abrasive machining process integrated both the two-body and three-body abrasion mode.

Performance characterization of powder mixed wire electrical discharge machining technique for processing of Ti6Al4V alloy

2021 ◽  
pp. 095440892110607
Author(s):  
Sadananda Chakraborty ◽  
Souren Mitra ◽  
Dipankar Bose
Keyword(s):  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Ti6al4v Alloy ◽  
Machining Process ◽  
Wire Electrical Discharge Machining ◽  
Powder Concentration ◽  
Pulse Off Time ◽  
Off Time

Precision machining characteristics with high-dimensional accuracy make the material more adaptable towards the applications. The present study employs the powder mixed wire electrical discharge machining process to machine Ti6Al4V alloy material. In spite of limited drawbacks and enhanced output in the powder mixed wire electrical discharge machining process, the present problem has been formulated for improving the machining efficiency of Ti6Al4V. The impact of suspended powder characteristics on responses, that is, material removal rate and surface roughness, is examined throughout the process. The current investigation also focuses on the interaction effect of machining constraints along with Al2O3 abrasive mixed dielectric to achieve economical machining output for the Ti6Al4V material. An effort has been presented to obtain optimal solutions using the different methodologies, namely response surface methodology, grey relation analysis, and particle swarm optimization. The study reveals that discharge energy is deeply influenced by the peak current and pulse off time followed by powder concentration in the powder mixed wire electrical discharge machining process. The maximum material removal rate of 6.628 mm3/min and average surface finish of 1.386 μm are the outcome of the present study for a set of optimal machining settings, that is, pulse off time ( Toff) of 7.247 μs, pulse on time ( Ton) of 30 μs, peak current ( Ip) of 2 A, and powder concentration of 4 g/L. Finally, the proposed model has been verified that the hybrid particle swarm optimization technique has the highest adequate capability to achieve maximum output. Thus, the approach offered an enhancement on performance measures of Ti6Al4V alloy in the powder mixed wire electrical discharge machining process.

Burr Formation and Surface Quality in High Speed Micromilling of Titanium Alloy (Ti6Al4V)

2013 ◽  
Author(s):  
Vivek Bajpai ◽  
Ajay K. Kushwaha ◽  
Ramesh K. Singh
Keyword(s):  
High Speed ◽  
Removal Rate ◽  
Weight Ratio ◽  
Machining Process ◽  
Burr Formation ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Good Surface ◽  
Mechanical Machining ◽  
Tool Diameter

Titanium and Ti alloys are popular materials used in aviation and biomedical field due to their excellent strength-to-weight ratio and corrosion resistance properties. Micromilling is a common mechanical machining process used in the production of microscale features. The micro-tool has very low stiffness and even small forces can lead to catastrophic tool failure. High speed micromachining can be used to address the issue because of lower chip loads at higher rotational speeds. Consequently, high speed micromilling can be used for micromachining of hard metals/alloys which are difficult to accomplish at lower speeds. Nowadays high speed micromilling is gaining popularity due to its high material removal rate and good surface finish. In many cases, the machined product does not need an additional finishing process. However, the burr formation in the mechanical machining process is the most important problem which becomes more critical for a microscale feature. Removal of micro-size burr is much more difficult than its macro counterpart. The current work is focused on the characterization of the burr formation in high speed micromilling. Influence of various process parameters, viz., spindle speed, feed rate, depth of cut, tool diameter and number of flutes of the micromilling tool has been analyzed on the burr size and on the quality of the machined surface via measuring the surface roughness.

Study on the Effect of Tool Polarity and Tool Rotation during EDM of Non-Conductive Ceramics

2014 ◽  
Vol 941-944 ◽  
pp. 2127-2133 ◽  
Author(s):  
Nirdesh Ojha ◽  
Florian Zeller ◽  
Claas Mueller ◽  
Holger Reinecke
Keyword(s):  
Material Properties ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Ceramic Materials ◽  
Machining Process ◽  
Electrode Wear ◽  
Conductive Material ◽  
Tool Rotation ◽  
Edm Process

The ability to machine advanced ceramic materials such as ZrO2, SiC, and AlN is of high interest for various industries because of the extraordinary material properties that these ceramics possess. Once sintered, these ceramics are characterized with high mechanical strength, high thermal stability and high chemical inertness. Therefore it is extremely difficult to machine these ceramics with dimensions in few microns using traditional techniques. Electrical discharge machining (EDM) is an electro-thermal machining process used to structure conductive materials. By applying a conductive layer on top of the non-conductive material, the EDM process can also be used to machine the non-conductive material. This paper presents a study on the effect of tool polarity and tool rotation on the material removal rate and electrode wear ratio during the EDM process of non-conductive SiC, ZrO2 and AlN ceramics. The reasons for the variation in the material removal rates among the different ceramics are examined by comparing the material properties. Relatively lower value of flexural strength, fracture toughness and melting temperature is the reason for AlN ceramic to have the higher MRR than SiC and ZrO2 ceramics.

A Study on the Die-Sinking Micro-Electrical Discharge Machining of EN-24 Die Steel Using Various Electrode Materials

2014 ◽  
Vol 984-985 ◽  
pp. 73-82 ◽  
Author(s):  
A. Kadirvel ◽  
P. Hariharan ◽  
M. Mudhukrishnan
Keyword(s):  
Surface Roughness ◽  
Electrode Materials ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Copper Electrode ◽  
Machining Process ◽  
Micro Edm ◽  
Processing Efficiency ◽  
Die Steel ◽  
Micro Holes

Micro-EDM is an extensively used machining process for the fabrication of micro-holes with various advantages resulting from its characteristics of non-contact and thermal process. In this micro-fabrication technique, processing parameters greatly affect processing efficiency and stability. An experimental investigation on die-sinking Micro-EDM of EN-24 die steel using various electrodes such as tungsten, copper, copper tungsten and silver tungsten has been carried out. The present study aims to assess the quality and accuracy of the produced micro-holes, machining stability, material removal rate (MRR), tool wear ratio (TWR), surface roughness (Ra), Heat affected zone (HAZ) and overcut (OC). In addition, the influence of gap voltage, capacitance and discharge energy on the performance of the process has also been investigated. Experimental results proved that the overall performance of the copper electrode is found to be optimum with high MRR, thin HAZ though copper shows higher TWR, surface roughness and overcut.

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