scholarly journals Investigation of Surface Modification of 60CrMoV18-5 Steel by EDM with Cu-ZrO2 Powder Metallurgy Green Compact Electrode

Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 268
Author(s):  
Maria Balanou ◽  
Panagiotis Karmiris-Obratański ◽  
Beata Leszczyńska-Madej ◽  
Emmanouil L. Papazoglou ◽  
Angelos P. Markopoulos
Keyword(s):  
Surface Modification ◽  
Powder Metallurgy ◽  
Electrical Discharge Machining ◽  
Surface Characteristics ◽  
Machining Process ◽  
Green Compact ◽  
Material Transfer ◽  
Machined Surface ◽  
Workpiece Surface ◽  
Conventional Machining

Electrical discharge machining (EDM) is a non-conventional machining process, which is mostly used for machining of difficult-to-cut materials. These materials are often used in engineering applications that require improved surface properties; thus, surface modification is desirable in these cases. In the recent past, it has been observed that EDM is an alternative surface modification process due to migration of material from the electrode to the workpiece surface. Surface modification can be done with powder metallurgy (P/M) electrode as tool. The aim of this work is to examine the surface modification of the tool steel Calmax (Uddeholm) by EDM process using Cu-30 wt.% ZrO2 P/M green compact electrode. The influence of peak current (Ip) and pulse-on (Ton) on the Material Transfer Rate (MTR) and Surface Roughness (SR) was investigated and the surface characteristics were also evaluated by scanning electron microscopy (SEM). The experimental results confirm the material migration from the electrode to the machined surface and show that the higher MTR of 46.5 mgr/min is achieved on the combination of Ip = 9 A and Ton = 25 μs and the Ra varies from 3.72 μm to 7.12 μm.

Optimization and surface modification in electrical discharge machining of AA 6061/SiCp composite using Cu–W electrode

2015 ◽  
Vol 231 (3) ◽  
pp. 332-348 ◽  
Author(s):  
Balbir Singh ◽  
Jatinder Kumar ◽  
Sudhir Kumar
Keyword(s):  
Process Parameters ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Surface Characteristics ◽  
Electrode Wear ◽  
Material Transfer ◽  
Machined Surface ◽  
Recast Layer Thickness ◽  
Pulse On Time ◽  
Pulse Off Time

This paper presents the experimental investigation on the electro-discharge machining of aluminum alloy 6061 reinforced with SiC particles using sintered Cu–W electrode. Experiments have been designed as per central composite rotatable design, using response surface methodology. Machining characteristics such as material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR) have been investigated under the influence of four electrical process parameters; namely peak current, pulse on time, pulse off time, and gap voltage. The process parameters have been optimized to obtain optimal combination of MRR, EWR, and SR. Further, the influence of sintered Cu–W electrode on surface characteristics has been analyzed with scanning electron microscopy, energy dispersive spectroscopy, and Vicker microhardness tests. The results revealed that all the process parameters significantly affect MRR, EWR, and SR. The machined surface properties are modified as a result of material transfer from the electrode. The recast layer thickness is increased at higher setting of electrical parameters. The hardness across the machined surface is also increased by the use of sintered Cu–W electrode.

Surface Morphology and Corrosion Behavior in Nano PMEDM

2016 ◽  
Vol 724 ◽  
pp. 61-65 ◽  
Author(s):  
Ahmad Majdi Abdul-Rani ◽  
Alexis Mouangue Nanimina ◽  
Turnad Lenggo Ginta
Keyword(s):  
Titanium Alloy ◽  
Corrosion Rate ◽  
Surface Morphology ◽  
Surface Quality ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Machining Process ◽  
Application Process ◽  
Machined Surface ◽  
Conventional Machining

This research study was conducted to investigate the effect of nanoaluminum powder mixed electrical discharge machining (PMEDM) on surface morphology and corrosion rate of titanium alloy material. The development of devices such as implants in biomedical engineering application nowadays requires materials having good mechanical and physical properties. Conventional machining process of titanium as implant is a challenge resulting relative poor surface quality. Even using electrical discharge machining (EDM) which is non-conventional machining process there are limitations including machined surface alteration with relative poor machined surface quality, low corrosion resistance and. PMEDM is hypothesized to address the above mentioned problems. In this study, PMEDM on titanium alloy using nanoaluminum powder and copper-tungsten electrode was assessed to investigate the improvement for implant application. Process parameters used are peak-current, ON-time, gap voltage and powder concentration. Surface morphology and average corrosion arte are selected output responses. Results showed that Surface morphology of PMEDM machined surface is significantly improved. PMEDM marginally enhanced corrosion rate of biomedical grade titanium alloy.

Surface Modification by EDM Using Co-Cr Sintered Powder Metallurgy Electrode

2012 ◽  
Vol 576 ◽  
pp. 56-59 ◽  
Author(s):  
Ahsan Ali Khan ◽  
Mohammed Baba Ndaliman ◽  
Mohammad Yeakub Ali ◽  
Mas Hafizah Bt Mansor ◽  
Nurul Ain Bt Idrus
Keyword(s):  
Powder Metallurgy ◽  
Mild Steel ◽  
Electrode Materials ◽  
Electrical Discharge Machining ◽  
Surface Hardness ◽  
Surface Characteristics ◽  
Dielectric Fluid ◽  
Pulse Interval ◽  
Spectroscopy Analysis ◽  
Sintered Electrode

In this investigation, the powder metallurgy (PM) electrode developed from cobalt (Co) and chromium (Cr) powders was used in electrical discharge machining (EDM). This new Co-Cr sintered electrode was used to machine mild steel workpiece with kerosene dielectric fluid. The main objective is to modify its surface characteristics and secure increased surface hardness. The EDM variables of peak current, pulse duration and pulse interval were applied to investigate these surface properties. Scanning electron microscopy (SEM) / energy dispersive X-ray (EDX) spectroscopy analysis confirmed migration of electrode materials (Co and Cr) onto the EDMed surface. Improved hardness was obtained on the mild steel, the highest being 85.3 HRB. Thus, the Co-Cr electrode introduced into the EDM has the capability of modifying the mild steel surface.

scholarly journals Surface Roughness Analysis of H13 Steel during Electrical Discharge Machining Process Using Cu–TiC Sintered Electrode

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5943
Author(s):  
Arminder Singh Walia ◽  
Vineet Srivastava ◽  
Mayank Garg ◽  
Nalin Somani ◽  
Nitin Kumar Gupta ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Electrical Discharge ◽  
Pulse Current ◽  
Electrical Discharge Machining ◽  
Machining Process ◽  
H13 Steel ◽  
Machined Surface ◽  
Machined Surface Quality ◽  
Semi Empirical

In electrical discharge machining (EDM), the machined surface quality can be affected by the excessive temperature generation during the machining process. To achieve a longer life of the finished part, the machined surface quality plays a key role in maintaining its overall integrity. Surface roughness is an important quality evaluation of a material’s surface that has considerable influence on mechanical performance of the material. Herein, a sintered cermet tooltip with 75% copper and 25% titanium carbide was used as tool electrode for processing H13 steel. The experiments have been performed to investigate the effects of EDM parameters on the machined surface roughness. The findings show that, as the pulse current, pulse length, and pulse interval are increased, the surface roughness tends to rise. The most significant determinant for surface roughness was found to be pulse current. A semi-empirical surface roughness model was created using the characteristics of the EDM technique. Buckingham’s theorem was used to develop a semi-empirical surface roughness prediction model. The semi-empirical model’s predictions were in good agreement with the experimental studies, and the built empirical model based on physical features of the cermet tooltip was tested using dimensional analysis.

Laser Surface Modification of Wire-Electric Discharge Machined Graphene Nanoparticle Reinforced SiC Composites

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Meinam Annebushan Singh ◽  
Ondrej Hanzel ◽  
Ramesh Kumar Singh ◽  
Pavol Šajgalík ◽  
Deepak Marla
Keyword(s):  
Surface Modification ◽  
Repetition Rate ◽  
Pulse Repetition Rate ◽  
Laser Processing ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Surface Characteristics ◽  
Scanning Speed ◽  
Laser Surface ◽  
Laser Surface Modification

Abstract Electrical discharge machining of conducting ceramics is often associated with high roughness and porosity, which hinders their application. This porosity-laden surface morphology necessitates a postprocessing technique to reduce the severity of the surface defects. Hence, this study focuses on the utilization of a nanosecond pulsed laser as a surface modification tool to minimize the debris and pores formed on the surface after the wire-electrical discharge machining process. This paper presents a study on the influence of laser parameters, viz., power, number of scans, scanning speed, and pulse repetition rate on the overall surface characteristics. The concentration of surface debris and pores were observed to significantly decrease with laser surface modification (LSM). The improvement in the surface characteristics after laser processing with low fluence was mainly attributed to melting, vaporization, and subsequent flow of molten material, which led to filling of the surface pores. This resulted in a more even surface postlaser surface modification. The surface roughness was observed to decrease by ∼49% after the laser processing at lower values of laser power, number of scans, and scanning speed and at higher values of pulse repetition rate. Furthermore, spatial, hybrid, and functional volume characteristics were observed to improve postlaser modification. However, at higher laser fluence, the processed surfaces were observed to get further worsened with the formation of deep ridges.

Surface Study in a Non-conventional (Electrical Discharge Machining) Process for Grade 6 Titanium Material

2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Md. Ashikur Rahman Khan ◽  
M. M. Rahman
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Machining Process ◽  
Machined Surface ◽  
Titanium Material ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time

Electrical discharge machining (EDM) produces complex shapes and permits high-precision machining of any hard or difficult-to-cut materials. The performance characteristics such as surface roughness and microstructure of the machined face are influenced by numerous parameters. The selection of parameters becomes complicated. Thus, the surface roughness (Ra) and microstructure of the machined surface in EDM on Grade 6 titanium alloy are studied is this study. The experimental work is performed using copper as electrode material. The polarity of the electrode is maintained as negative. The process parameters taken into account in this study are peak current (Ip), pulse-on time (Ton), pulse-off time (Toff), and servo-voltage (Sv). A smooth surface finish is found at low pulse current, small on-time and high off-time. The servo-voltage affects the roughness diversely however, a finish surface is found at 80 V Sv. Craters, cracks and globules of debris are appeared in the microstructure of the machined part. The size and degree of craters as well as cracks increase with increasing in energy level. Low discharge energy yields an even surface. This approach helps in selecting proper process parameters resulting in economic EDM machining. 

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.

Migration of Materials during Finishing Micro-EDM of Tungsten Carbide

2010 ◽  
Vol 443 ◽  
pp. 681-686 ◽  
Author(s):  
Muhammad Pervej Jahan ◽  
Mustafizur Rahman ◽  
Yoke San Wong
Keyword(s):  
Tungsten Carbide ◽  
Surface Defects ◽  
Surface Characteristics ◽  
Lower Amount ◽  
Tool Electrode ◽  
Micro Edm ◽  
Tungsten Electrode ◽  
Machined Surface ◽  
Workpiece Surface ◽  
Carbon Migration

Present study aims to investigate the migration of materials onto the surface of workpiece and electrode during fine-finish die-sinking and milling micro-EDM of tungsten carbide using pure tungsten electrode. The effect of materials transfer on the machined surface characteristics is also presented. The machined surfaces have been examined under scanning electron microscope (SEM) and energy dispersive X-ray (EDX) in order to investigate the changes in chemical composition due to the migration of materials. It has been observed that materials from both workpiece and electrode transfer to each other depending on machining conditions and discharge energy. A significant amount of carbon migrates to both electrode and workpiece surface due to the decomposition of dielectric hydrocarbon during breakdown. The migration occurs more frequently at lower gap voltages during finish die-sinking micro-EDM due to low spark gap and stationary tool electrode. Milling micro-EDM suffers from lower amount of carbon migration and fewer surface defects which improve the overall surface finish and reduce surface roughness significantly.

Surface Modification Using Electric Discharge Machining (EDM) with Powder Addition

2011 ◽  
Vol 110-116 ◽  
pp. 725-733 ◽  
Author(s):  
Ahsan Ali Khan ◽  
Mohammed Baba Ndaliman ◽  
Zakaria Mohd Zain ◽  
Mohammad F. Jamaludin ◽  
Umar Patthi
Keyword(s):  
Surface Modification ◽  
Layer Thickness ◽  
Electrical Discharge Machining ◽  
Tool Material ◽  
Dielectric Medium ◽  
Tungsten Electrode ◽  
Machined Surface ◽  
Al2o3 Powder ◽  
Recast Layer Thickness ◽  
Powder Addition

Powder mixed electrical discharge machining (PMEDM) is one of the recent innovations for the enhancement of the capabilities of EDM process. In this study, the effects of powder addition on the surface modification of mild steel were investigated. Copper tungsten electrode was used in the machining. Two different powders namely TiC and Al2O3 were used in the study with kerosene as the dielectric medium. The powder types and currents were manipulated to study their effects on the machined surface. The results show that increasing the current leads to increase in recast layer thickness, and the cracks. The Al2O3 powder gave higher layer thickness than TiC powder. TiC Powder addition also produced higher hardness, more tool material and carbon depositions on the work surface than Al2O3 powder.

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