scholarly journals Pulse-Type Influence on the Micro-EDM Milling Machinability of Si3N4–TiN Workpieces

Micromachines ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 932 ◽  
Author(s):  
Valeria Marrocco ◽  
Francesco Modica ◽  
Vincenzo Bellantone ◽  
Valentina Medri ◽  
Irene Fassi
Keyword(s):  
Tool Wear ◽  
Removal Rate ◽  
Micro Edm ◽  
Remarkable Effect ◽  
Post Process ◽  
Electro Discharge Machining ◽  
Micro Cracks ◽  
Pulse Type ◽  
Micro Features

In this paper, the effect of the micro-electro discharge machining (EDM) milling machinability of Si3N4–TiN workpieces was investigated. The material removal rate (MRR) and tool wear rate (TWR) were analyzed in relation to discharge pulse types in order to evaluate how the different pulse shapes impact on such micro-EDM performance indicators. Voltage and current pulse waveforms were acquired during micro-EDM trials, scheduled according to a Design of Experiment (DOE); then, a pulse discrimination algorithm was used to post-process the data off-line and discriminate the pulse types as short, arc, delayed, or normal. The analysis showed that, for the considered process parameter combinations, MRR was sensitive only to normal pulses, while the other pulse types had no remarkable effect on it. On the contrary, TWR was affected by normal pulses, but the occurrence of arcs and delayed pulses induced unexpected improvements in tool wear. Those results suggest that micro-EDM manufacturing of Si3N4–TiN workpiece is relevantly different from the micro-EDM process performed on metal workpieces such as steel. Additionally, the inspection of the Si3N4–TiN micro-EDM surface, performed by SEM and EDS analyses, showed the presence of re-solidified droplets and micro-cracks, which modified the chemical composition and the consequent surface quality of the machined micro-features.

Multi Response Optimization by Using the Hybrid Technique in Electro Discharge Machining of AISI 304

2016 ◽  
Vol 26 ◽  
pp. 68-75 ◽  
Author(s):  
Munmun Bhaumik ◽  
Kali Pada Maity
Keyword(s):  
Wear Rate ◽  
Tool Wear ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Tool Wear Rate ◽  
Aisi 304 ◽  
Relational Analysis ◽  
Electro Discharge Machining ◽  
Grey Relational

Electro discharge machining (EDM) is most popular non-conventional electro-thermal machining process where electrical energy is used to generate a spark and thermal energy used to remove material from the workpiece. The primary goal of EDM is getting more material removal rate (MRR) with lower tool wear rate (TWR). For this investigation, machining parameters like peak current, pulse on time, gap voltage and duty cycle are considered as process parameter, and material removal rate (MRR) and tool wear rate (TWR) are considered as response. AISI 304 stainless steel and tungsten carbide are used as work material and tool material respectively. Taguchi L27 orthogonal array has been applied for designing the experiment. A hybrid optimization technique like desirability in combination with grey relational analysis (GRA) has been performed to get the optimum level of the control parameter for getting higher MRR and lower TWR. Analysis of variance (ANOVA) is performed for the statistical analysis. These results show that peak current is the most significant parameter for MRR and TWR. The optimal parameter setting for maximum MRR and minimum TWR has obtained by desirability coupled with Grey relational analysis.

Evaluation of Micro-EDM Milling Performance Using Pulse Discrimination

2014 ◽  
Author(s):  
F. Modica ◽  
G. Guadagno ◽  
V. Marrocco ◽  
I. Fassi
Keyword(s):  
Tool Wear ◽  
Process Parameters ◽  
Pulse Width ◽  
Removal Rate ◽  
Micro Edm ◽  
Erosion Process ◽  
Machining Performance ◽  
Short Pulses ◽  
Milling Performance ◽  
Micro Channels

In this paper, the pulse discrimination of gap voltage and discharge current waveforms occurring during micro-EDM milling of micro-channels is analyzed in relation to process parameters variation and machining performance. The pulse classification algorithm discriminates voltage and current waveforms into four defined pulse types: short, arc, delayed and normal. The micro-channels are manufactured in hardened steel using an energy level corresponding to the finishing regime and varying pulse width, frequency, gain and gap. The analysis shows that when the erosion process is stable, normal discharges are predominant. Delayed and short pulses are very sporadic. A major number of arcs can be detected when the gap is decreased and gain increased, i.e. erosion speed and feed rate are increased and affect in particular tool wear. Also the increase of the pulse width has an effect on tool wear, though the percentage of the arcs remains small. On the contrary, material removal rate does not seem to be apparently related to the percentage of arcs as the process parameters are varied, since these values are spread in a constant range for all parameter combinations. The evaluation of the depth errors does not provide any significant insights about the erosion process in relation to the considered process parameters.

Effect of Tool Wear on Force and Quality in Dam-Bar Cutting of Integrated Circuit Packages

2000 ◽  
Vol 123 (1) ◽  
pp. 34-41 ◽  
Author(s):  
C. F. Cheung ◽  
W. B. Lee ◽  
W. M. Chiu
Keyword(s):  
Tool Wear ◽  
Integrated Circuit ◽  
Printed Circuit Boards ◽  
Cutting Tools ◽  
Cutting Process ◽  
Post Process ◽  
Process Failure ◽  
Important Means ◽  
Experimental Findings

Dam-bar cutting is an essential trimming process in which the dam-bars in between the leads of Integrated Circuit (IC) packages are removed after encapsulation and deflashing. There are stringent requirements imposed on the quality of the sheared dam-bar edges so as to avoid the post-process failure of the package during assembly on to printed circuit boards. In this paper, a detailed analysis of the wear characteristics of the dam-bar cutting tools and their effects on the force and quality of dam-bar cutting process is reported. The correlation between the peak dam-bar cutting force and the tool wear was also studied under various combinations of wear states of the punch and die. Based on the experimental findings, relationships have been built to correlate the states of wear of the punch and die to the protrusion and burr height of the dam-bar sheared edge. Hence, revised tool life criteria were proposed for the quality control of dam-bar cutting process. The results of the analysis provide an important means for the on-line monitoring of tool wear and edge quality of dam-bar cutting process in the IC packaging industry.

Verification of On-Line Computer Control of EDM by Data Dependent Systems

1987 ◽  
Vol 109 (2) ◽  
pp. 117-121 ◽  
Author(s):  
S. M. Pandit ◽  
T. M. Mueller
Keyword(s):  
Tool Wear ◽  
Metal Removal ◽  
Removal Rate ◽  
Computer Control ◽  
Electro Discharge Machining ◽  
Manual Adjustment ◽  
Machine Manufacturer ◽  
On Line ◽  
Edm Process ◽  
Line Analysis

A new method of computer control of electro-discharge machining based on Data Dependent Systems (DDS) methodology has been recently proposed. The control is based on a parameter which effectively represents the resistance of arc and is isolated by the DDS model from the random current and voltage signals in spite of the large noise. This paper presents an experimental verification to show that this parameter indeed represents the arc resistance which cannot be measured by any other means and that the parameter is quite sensitive to the change from beneficial sparking condition to the harmful arcing condition. Off-line analysis of the EDM process under different conditions is presented with this parameter as the response variable. Development of the control strategy using the results of this analysis is illustrated. Implementation of the strategy by means of a Motorola microcomputer is described. A comparison of metal removal rate (MRR), surface roughness, and tool wear for the computer control and the optimal manual adjustment recommended by the EDM machine manufacturer is presented. It shows that the computer control yields an increase in the MRR of 47 percent and 19 percent, while the ratio of tool wear to MRR reduces by 26 percent and 16 percent, respectively, in finishing and roughing conditions.

Micro Electro Discharge Machining of CNT-Based Nanocomposite Materials

2007 ◽  
Author(s):  
Yi Wan ◽  
Dae-Wook Kim ◽  
Jae-Soon Jang ◽  
Young-Bin Park
Keyword(s):  
Polymer Composites ◽  
Supply Voltage ◽  
Removal Rate ◽  
High Energy ◽  
Ceramic Composites ◽  
Fractional Factorial ◽  
Micro Edm ◽  
Time Duration ◽  
Electro Discharge Machining ◽  
Pulse On Time

Since the discovery of carbon nanotubes (CNTs), there has been great interest in CNT-based composites. Well-developed micromachining processes are necessary to realize micron-size CNT-based composite products. Micro electro discharge machining (micro-EDM) has been applied into many challenge-to-cut materials such as ceramic composites. In this study, micro-EDM is used to machine CNT-reinforced polymer composites in the micro scale. CNT-based polymer composites were fabricated using solution casting, in which CNTs were dispersed in the polymer-solvent solution via high energy sonication, followed by precipitation and hot pressing. The investigation uses design of experiments (DOE) approach to screen of influential input factors for process measures. A 2 level fractional factorial design was used with four input factors; CNT loading on the workpiece, μ-EDM supply voltage, pulse on-time duration, and pulse on-time ratio. With 16 μ-EDM experiments, supply voltage was found to be most influential to the material-removal-rate (MRR). Scanning electron microscope (SEM) was used to investigate characteristics of the machined CNT-based nanocomposite surfaces.

scholarly journals Effect of Micro-EDM Parameters on Material Removal Rate of Nonconductive ZrO2 Ceramic

2013 ◽  
Vol 465-466 ◽  
pp. 1329-1333 ◽  
Author(s):  
Abdus Sabur ◽  
Abdul Moudood ◽  
Mohammad Yeakub Ali ◽  
Mohammad Abdul Maleque
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Pyrolytic Carbon ◽  
Carbon Layer ◽  
Machining Process ◽  
Machining Parameters ◽  
Micro Edm ◽  
Machined Surface ◽  
Electro Discharge Machining

Micro-electro discharge machining (micro-EDM) technique, an advanced noncontact machining process, is used for structuring of nonconductive ZrO2 ceramic. In this study copper foil as a conductive layer is adhered on the workpiece surface to initiate the sparks and kerosene is used as dielectric for creation of continuous conductive pyrolytic carbon layer on the machined surface. Voltage (V) and capacitance (C) are considered as the parameters to investigate the process capability of machining parameters in continuous micro-EDM of ZrO2. Different voltage pulses are studied to examine the causes of lower material removal rate (MRR) in micro-EDM of nonconductive ceramics. The results showed that in micro-EDM of ZrO2 MRR increases with the increase of voltage and capacitance initially, but decreases at higher values and no significant materials are removed at capacitances higher than 1nF.

Effect of Tool Electrode Material on the Spark Erosion of Micro Grooves

2006 ◽  
Vol 526 ◽  
pp. 79-84
Author(s):  
S.H. Yeo ◽  
M. Murali ◽  
S. Balakrishnan
Keyword(s):  
Material Removal ◽  
Electrode Materials ◽  
Removal Rate ◽  
Experimental Investigations ◽  
Tool Electrode ◽  
Micro Edm ◽  
Rough Machining ◽  
Electro Discharge Machining ◽  
Spark Erosion ◽  
Materials Used

Micro electro discharge machining is an important unconventional metal micromachining technology. The performance of micro EDM depends on the combination of the tool and work materials used. In the absence of a comprehensive theoretical model to predict the effect of electrode materials on the performance of EDM, experimental investigations as described in this paper become useful. The work materials studied include ferrous, non-ferrous and exotic material (XW42, Ti6Al4V, WC) and the tool electrode materials include the commonly used EDM tool materials namely tungsten, copper and graphite. It is found that in the microgroove machining by micro EDM using foil electrodes, graphite consistently provides higher material removal rate than tungsten and copper tool electrodes and hence it is useful for the rough machining. On the other hand tungsten tool electrode is preferable for finish machining as it provides the least surface roughness.

Investigating the Micro-EDM Machinability of Bulk Metallic Glass in Micro-EDM Drilling

2019 ◽  
Author(s):  
Chong Liu ◽  
Asif Rashid ◽  
Muhammad P. Jahan ◽  
Jianfeng Ma
Keyword(s):  
Aspect Ratio ◽  
Wear Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Dimensional Accuracy ◽  
Tool Electrode ◽  
Micro Edm ◽  
Tool Wear Rate ◽  
Micro Holes

Abstract Bulk Metallic Glass (BMG) is a solid metallic material with disordered atomic structure, that has the characteristics of high elasticity, hardness, fracture toughness, and superior corrosion resistance. High aspect ratio micro-through holes on BMG has prospective applications in space, nuclear reactor, thermodynamics engineering, biomedical, and electronics industries. In this study, the micro-EDM machinability of BMG (Vit 1b: Zr67Cu10.6Ni9.8Ti8.8Be3.8 (wt%)) is evaluated. The micro-EDM machinability of BMG has been assessed based on the volume of material removal rate (MRR), tool wear rate (TWR), micro-hole surface quality, and dimensional accuracy. The effect of various electrical and non-electrical parameters is studied. It is found that micro-EDM is capable producing high aspect ratio micro-holes on difficult-to-machine BMG. The deposition of resolidified debris around the edge of the micro-holes, both at the entrance and exit side, are found to be a common phenomenon in micro-EDM of BMG. The reduction of capacitance was found to be the effective way for reducing the resolidified debris around the edges. Capacitance was found to be have more pronounced effect, with gap voltage having little effect on the quality of micro-holes. The electrode rotational speed had insignificant effect on the quality of micro-holes. In terms of dimensional accuracy, which was measured by overcut and taper angle, both the gap voltage and electrode rotational speed had little effect. The lower electrode rpm was found to reduce the taperness of the micro-holes, although the material removal rate decreases and tool wear rate increases. Finally, analysis of the composition of tool electrode before and after machining indicates the migration of materials from the dielectric and workpiece to the tool electrode and vice versa.

scholarly journals Micro Electro Discharge Machining of Polymethylmethacrylate (PMMA)/Multi-Walled Carbon Nanotube (MWCNT) Nanocomposites

2008 ◽  
Vol 17 (4) ◽  
pp. 096369350801700 ◽  
Author(s):  
Yi Wan ◽  
Dave (Dae-Wook) Kim ◽  
Young-Bin Park ◽  
Sung-Kwan Joo
Keyword(s):  
Carbon Nanotube ◽  
Material Removal ◽  
Supply Voltage ◽  
Removal Rate ◽  
High Energy ◽  
Material System ◽  
Micro Edm ◽  
Electro Discharge Machining ◽  
Multi Walled Carbon Nanotube ◽  
Mwcnt Loading

This study investigated micro electro discharge machining (micro-EDM) of Polymethylmethacrylate (PMMA)/Multi-Walled Carbon Nanotube (MWCNT) nanocomposites. PMMA/MWCNT nanocomposites were fabricated using solution casting, in which MWCNTs were dispersed in the polymer-solvent solution via high energy sonication, followed by precipitation and hot pressing. MWCNT loading was varied to investigate the effect of electrical conductivity of nanocomposites on the machinability. Micron-size holes were created to study the material removal mechanism in micro-EDM. The electro discharge phenomena may occur between electrically conductive MWCNT and the tungsten electrode during the process. As a result, PMMA/MWCNT nanocomposite samples with 10 to 35 wt% MWNTs were able to be EDMed with proper machining conditions. It was observed that the material removal rate increases with increasing micro-EDM supply voltage and MWCNT loading on the material system. Both optical microscope and scanning electron microscope (SEM) were used to investigate the characteristics of the machined holes and nanocomposite surfaces.

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