The surface integrity of ultra-fine grain steel, Electrical discharge machined using Iso-pulse and resistance–capacitance-type generator

2020 ◽  
Vol 234 (4) ◽  
pp. 564-573
Author(s):  
Mohammad S Mahdieh
Keyword(s):  
Surface Integrity ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
High Strength ◽  
Functional Method ◽  
Machining Process ◽  
Machining Parameters ◽  
Fine Grained ◽  
Hardness Tester ◽  
Angular Pressing

Ultra-fine grained materials with high strength and low weight are eventually considered to be used in industries. To produce ultra-fine grained materials, equal channel angular pressing is a functional method, imposing severe plastic deformation on the workpiece. Electrical discharge machining is an indispensable process in manufacturing industrial parts with high accuracy and precision. However, electrical discharge machining has thermo-physical consequences, damaging the surface layers of the workpiece. On the other hand, the ultra-fine grained materials are thermodynamically unstable and tend to microstructural evolution. Thus, electrical discharge machining process affects the ultra-fine grained materials more than coarse grain materials. In this study, the effects of electrical discharge machining on the ultra-fine grained steel were investigated and the undesirable influences of the electrical discharge machining were diminished by adjusting the electrical discharge machining parameters. The ultra-fine grained steel samples were electrical discharge machined in two methods including Iso-pulse (roughing mode and finishing mode) and with resistance–capacitance-type generator. The surface integrity parameters, including thickness and microstructure of the recast layer and heat-affected zone, the cracks density and hardness, which for all three types of samples, were investigated by scanning electron microscopy, optical microscopy, X-ray diffraction technique, and micro-hardness tester. The results show that electrical discharge machining with resistance–capacitance-type generator has the minimum effects on the surface integrity of the ultra-fine grained samples because of the different material removal mechanism of resistance–capacitance-type electrical discharge machining.

scholarly journals Development and Investigation of an Inexpensive Low Frequency Vibration Platform for Enhancing the Performance of Electrical Discharge Machining Process

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6192
Author(s):  
Abhimanyu Singh Mertiya ◽  
Aman Upadhyay ◽  
Kaustubh Nirwan ◽  
Pravin Pandit Harane ◽  
Ahmad Majdi Abdul-Rani ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Low Frequency ◽  
Machining Process ◽  
Machining Parameters ◽  
Peak Current ◽  
Low Frequency Vibration ◽  
Debris Removal ◽  
Vibration Assistance ◽  
Discharge Gap

Difficulty in debris removal and the transport of fresh dielectric into discharge gap hinders the process performance of electrical discharge machining (EDM) process. Therefore, in this work, an economical low frequency vibration platform was developed to improve the performance of EDM through vibration assistance. The developed vibratory platform functions on an eccentric weight principle and generates a low frequency vibration in the range of 0–100 Hz. The performance of EDM was evaluated in terms of the average surface roughness (Ra), material removal rate (MRR), and tool wear rate (TWR) whilst varying the input machining parameters viz. the pulse-on-time (Ton), peak current (Ip), vibration frequency (VF), and tool rotational speed (TRS). The peak current was found to be the most significant parameter and contributed by 78.16%, 65.86%, and 59.52% to the Ra, MRR, and TWR, respectively. The low frequency work piece vibration contributed to an enhanced surface finish owing to an improved flushing at the discharge gap and debris removal. However, VF range below 100 Hz was not found to be suitable for the satisfactory improvement of the MRR and reduction of the TWR in an electrical discharge drilling operation at selected machining conditions.

scholarly journals Comparative Study on EDM of Ti-6Al-4V Using Circular and Convex Shaped Electrodes

2018 ◽  
Vol 7 (3.34) ◽  
pp. 256
Author(s):  
S Rajamanickam ◽  
R Palani ◽  
V Sathyamoorthy ◽  
Muppala Jagadeesh Varma ◽  
Shaik Shaik Mahammad Althaf ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Industrial Applications ◽  
Copper Electrode ◽  
Machining Process ◽  
Project Work ◽  
Machining Parameters ◽  
Pulse On Time ◽  
Pulse Off Time

As on today, Electrical Discharge Machining (EDM) is world famous unconventional machining process for electrically conductive materials. In this project work, Ti-6Al-4V is performed in electrical discharge machining using differently shaped (circular and convex) copper electrode. The machining parameters considered are the pulse on- time, pulse off-time, voltage and current to investigate machining characteristics like material removal rate and tool wear rate. Taguchi method is applied to frame experimental design. Ti-6Al-4V finds wide usage in industrial applications such as marine, aerospace, bio-medical and so on. 

Evaluation of Electrical Discharge Machining Performance on Al (6351)–SiC–B4C Composite

2019 ◽  
pp. 109-124
Author(s):  
Uthayakumar M. ◽  
Suresh Kumar S. ◽  
Thirumalai Kumaran S. ◽  
Parameswaran P.
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Research Work ◽  
Machining Process ◽  
Electrode Wear ◽  
Machining Parameters ◽  
Machining Performance ◽  
Machined Surface ◽  
Output Performance ◽  
B4c Particles

Electrical discharge machining (EDM) process is a non-conventional machining process used for the material which are difficult to machine. In this research work, an attempt has been made to determine the influence of Boron Carbide (B4C) particles on the machinablity of the Al (6351) alloy reinforced with 5 wt. % Silicon Carbide (SiC) Metal Matrix Composite (MMC) through EDM. Influence of machining parameters such as pulse current (I), pulse on time (Ton), duty factor (τ), and gap voltage (V) on affecting the output performance characteristics namely Electrode Wear Ratio (EWR), Surface Roughness (SR) and Power Consumption (PC) which are studied. The result shows that the addition of B4C particles significantly affects the machinablity of the composite, with a contribution of 1.6% on EWR, 3.5% on SR and 19.8% on PC. The crater, recast layer formation, and Heat Affected Zone (HAZ) in the machined surface of the composite are also reported in detail.

An Investigation of the Influences of EDM Parameters and Tool Geometries on Radial Overcut for Monel 400 Material with Tungsten Copper Electrode

2015 ◽  
Vol 766-767 ◽  
pp. 908-913
Author(s):  
P. Padmini ◽  
S. Senthamilperarasu ◽  
B. Shanmuganathan ◽  
N.R.R. Anbusagar ◽  
P. Sengottuvel
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Dimensional Accuracy ◽  
Copper Electrode ◽  
Machining Process ◽  
Experimental Result ◽  
Machining Parameters ◽  
Radial Overcut ◽  
Monel 400 ◽  
Pulse On Time

Electrical-discharge Machining (EDM) is a nonconventional machining process utilizing an electric spark discharge from the electrode (-) towards the work piece (+) through the dielectric fluid. The Dimensional accuracy in this is very important consideration for the accuracy of the finished product. The objective of this experimental study is to determine parameters that offer the best dimensional accuracy in electrical discharge machining (EDM). Discharge current (A), Pulse On Time (Ton), Pulse Off Time (Toff ) and Circle,Rectangle,Triangle and Square Tool Geometrical Shapes (Geo) are taken as machining parameters. The experimental investigations are carried out on Monel 400 material using Tungsten copper electrode. The response of ROC is considered for improving the machining efficiency. Optimal combination of parameters was obtained Taguchi Optimization technique. The confirmation experiments results shows that the significant improvement in Radial Overcut was obtained. ANOVA have been used to analyze the contribution of individual parameters on ROC. The experimental result demonstrates that the Taguchi method satisfies the practical requirements

Effect of impregnated powder materials on surface integrity aspects of Inconel 625 during electrical discharge machining

2016 ◽  
Vol 232 (7) ◽  
pp. 1259-1272 ◽  
Author(s):  
Gangadharudu Talla ◽  
Soumya Gangopadhyay ◽  
CK Biswas
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Surface Integrity ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Machining Process ◽  
Inconel 625 ◽  
Powder Materials ◽  
Powder Concentration ◽  
Pulse On Time

In recent times, nickel-based super alloys are widely utilized in aviation, processing, and marine industries owing to their supreme ability to retain the mechanical properties at elevated temperature in combination with remarkable resistance to corrosion. Some of the properties of these alloys such as low thermal conductivity, strain hardening tendency, chemical affinity, and presence of hard and abrasives phases in the microstructure render these materials very difficult-to-cut using conventional machining processes. In this work, an experimental setup was developed and integrated with the existing electrical discharge machining system for carrying out powder-mixed electrical discharge machining process for Inconel 625. The experiments were planned and conducted by varying five different variables, that is, powder concentration, peak current, pulse-on time, duty cycle, and gap voltage based on the central composite design of response surface methodology. Effects of these parameters along with powder concentration were investigated on various surface integrity aspects including surface morphology, surface roughness, surface microhardness, change in the composition of the machined surface, and residual stress. Results clearly indicated that addition of powder to dielectric has significantly improved surface integrity compared to pure dielectric. Among the powders used, silicon has resulted in highest microhardness, that is, almost 14% more than graphite. Lowest surface roughness (approximately 50% less than pure kerosene) and least residual stress were obtained using silicon powder (approximately 8% less than graphite-mixed dielectric). Relative content of nickel was reduced at the expense of Nb and Mo after addition of powders like aluminum and graphite in dielectric during electrical discharge machining.

scholarly journals A study on Electrical Discharge Machining of Titanium Grade2 with experimental and theoretical analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emmanouil L. Papazoglou ◽  
Panagiotis Karmiris-Obratański ◽  
Beata Leszczyńska-Madej ◽  
Angelos P. Markopoulos
Keyword(s):  
Power Distribution ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
White Layer ◽  
Machining Process ◽  
Heat Transfer Analysis ◽  
Machining Parameters ◽  
Machining Performance ◽  
Plasma Flushing Efficiency

AbstractTitanium alloys, due to their unique properties, are utilized in numerous modern high-end applications. Electrical Discharge Machining (EDM) is a non-conventional machining process, commonly used in machining of hard-to-cut materials. The current paper, presents an experimental study regarding the machining of Titanium Grade2 with EDM, coupled with the development of a simulation model. The machining performance indexes of Material Removal Rate, Tool Wear Ratio, and Average White Layer Thickness were measured and calculated for different pulse-on currents and pulse-on times. Moreover, the developed model that integrates a heat transfer analysis with deformed geometry, allows to estimate the power distribution between the electrode and the workpiece, as well as the Plasma Flushing Efficiency, giving an insight view of the process. Finally, by employing the Response Surface Methodology, educed regression models that correlate the machining parameters with the corresponding results, while for all the aforementioned indexes, ANOVA was performed.

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