An investigation on gas emission concentration and relative emission rate of the near-dry wire-cut electrical discharge machining process

Author(s):  
Sampath Boopathi
2021 ◽  
Author(s):  
Boopathi Sampath

Abstract Wire-cut electrical discharge machining (WEDM) is the highly essential unconventional electro-thermal machining process to cut the contour profile of hard materials in modern production industries. The various environmental impacting wastes (by evaporating and reacting hydro-carbon dielectric fluid) are produced during the WEDM process and these are harmful to the machine operators. These wastes are minimized by a near-dry WEDM process wherein the pressurized air mixed with a small amount of water is used as a dielectric substance. In this research, influences, and contributions of machining parameters such as air pressure, mixing water flow rate, spark current and pulse width on gas emission concentration (GEC), materials removal rate (MRR), and relative emission rate (RER) of sustainable near-dry WEDM process have been optimized by Taguchi analysis. RER is investigated to analyze the effects of machining factors on gas emission and machining rate combinedly. It was revealed that the maximum air pressure and flow rate of mixing water have significantly been promoting the sustainable near-dry WEDM process.


Author(s):  
Gurpreet Singh ◽  
DR Prajapati ◽  
PS Satsangi

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.


Author(s):  
Sagil James ◽  
Sharadkumar Kakadiya

Shape Memory Alloys are smart materials that tend to remember and return to its original shape when subjected to deformation. These materials find numerous applications in robotics, automotive and biomedical industries. Micromachining of SMAs is often a considerable challenge using conventional machining processes. Micro-Electrical Discharge Machining is a combination of thermal and electrical processes, which can machine any electrically conductive material at micron scale independent of its hardness. It employs dielectric medium such as hydrocarbon oils, deionized water, and kerosene. Using liquid dielectrics has adverse effects on the machined surface causing cracking, white layer deposition, and irregular surface finish. These limitations can be minimized by using a dry dielectric medium such as air or nitrogen gas. This research involves the experimental study of micromachining of Shape Memory Alloys using dry Micro-Electrical Discharge Machining process. The study considers the effect of critical process parameters including discharge voltage and discharge current on the material removal rate and the tool wear rate. A comparison study is performed between the Micro-Electrical Discharge Machining process with using the liquid as well as air as the dielectric medium. In this study, microcavities are successfully machined on shape memory alloys using dry Micro-Electrical Discharge Machining process. The study found that the dry Micro-Electrical Discharge Machining produces a comparatively better surface finish, has lower tool wear and lesser material removal rate compared to the process using the liquid as the dielectric medium. The results of this research could extend the industrial applications of Micro Electrical Discharge Machining processes.


: This paper discusses the recent developments in the field of Electrical Discharge Machining (EDM) hybrid process. Spark machining is a universally recognised unconventional process, excluding the restriction of having low machining efficiency. To overcome this, various investigations have been made on designing of electrode, types of dielectric medium, variations in input parameters etc. Although material expulsion rate have been found to improve, nonetheless it cannot encounter the requirements of modern industries and the quality of surface is inferior. To increase further the utility of EDM, its hybridization with other process have to be carried out. A hybrid process can reduce the machining time while maintaining better surface and material expulsion rate. In hybrid process, the mechanism of two processes is applied concurrently or consecutively. Although, the performance of combined process is better as compared to the individual processes but hybridization increases the process complexity.


Author(s):  
M Adam Khan ◽  
A K Gokul ◽  
M.P Bharani Dharan ◽  
R.V.S Jeevakarthikeyan ◽  
M Uthayakumar ◽  
...  

Author(s):  
Sampath Boopathi

Abstract Electrical discharge machining (EDM) is very essential unconventional electro-thermal machining process to machine the contour profile of hard materials in modern production industries. The liquid dielectric fluid has been replaced by the gas and minimum quantity of liquid mixed with gas (gas-mist) to encourage the green machining processes. The various gases and gas-mist have been used as the working fluid in dry and near-dry EDM respectively. The research-contextual, various dielectric fluids, sustainable and innovative developments, process parameters, machining characteristics, and optimization techniques applied in various dry and near-dry EDM have been illustrated through an extensive literature survey. Future research opportunities in both dry and near-dry EDM have been summarized to promote eco-friendly EDM research activities.


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