Effect of Orbital Tool Actuation during Electro Discharge Machining Process - A Critical Review

2015 ◽  
Vol 85 (1-2) ◽  
pp. 49
Author(s):  
Sudhanshu Kumar ◽  
Harshit K. Dave ◽  
Keyur P. Desai
Author(s):  
J-B Li ◽  
K Jiang ◽  
G J Davies

A novel die-sinking micro-electro discharge machining (EDM) process is presented for volume fabrication of metallic microcomponents. In the process, a high-precision silicon electrode is fabricated using deep reactive ion etching (DRIE) process of microelectromechanical systems (MEMS) technology and then coated with a thin layer of copper to increase the conductivity. The metalized Si electrode is used in the EDM process to manufacture metallic microcomponents by imprinting the electrode onto a flat metallic surface. The two main advantages of this process are that it enables the fabrication of metallic microdevices and reduces manufacturing cost and time. The development of the new EDM process is described. A silicon component was produced using the Surface Technology Systems plasma etcher and the DRIE process. Such components can be manufactured with a precision in nanometres. The minimum feature of the component is 50 μm. In the experiments, the Si component was coated with copper and then used as the electrode on an EDM machine of 1 μm resolution. In the manufacturing process, 130 V and 0.2 A currents were used for a period of 5 min. The SEM images of the resulting device show clear etched areas, and the electric discharge wave chart indicates a good fabrication condition. The experimental results have been analysed and the new micro-EDM process is found to be able to fabricate 25 μm features.


2019 ◽  
Vol 303 ◽  
pp. 06002
Author(s):  
A. Bilal ◽  
A. Rashid ◽  
C. Liu ◽  
M. P. Jahan ◽  
D. Talamona ◽  
...  

Advanced ceramic materials possess superior mechanical characteristics in terms of hardness, wear resistance, fracture toughness and flexural strength. However, these materials experience machining limitations due to their hardness. Machining process of such materials requires high cutting forces and results in high tool wear. Electro- discharge machining (EDM) can be considered as an alternative machining process for advanced ceramics, since this technique is a non-contact machining process, it does not involve high cutting forces but experiences moderate tool wear. However, EDM requires materials to have certain level of electrical conductivity, therefore, non-conductive and semi-conductive ceramic materials experience challenges during machining process. Assisting Electrode Method was suggested as a solution for machining of non-conductive ceramics by EDM. In this method, conductive layer is applied on top of non-conductive ceramics and thus workpiece can be machined by EDM process using residual conductive layer. In this study, coating consisting of three layers, where silver nanoparticles were sandwiched between two layers of silver and copper on top, was used as assisting electrode to machine Aluminium Nitride (AlN) ceramics by silver nanoparticles mixed micro-EDM. Successful machining of AlN was demonstrated and blind micro hole with higher than three aspect ratio was achieved.


2018 ◽  
Vol 63 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Partha Protim Das ◽  
Sunny Diyaley ◽  
Shankar Chakraborty ◽  
Ranjan Kumar Ghadai

Wire electro discharge machining (WEDM) is a versatile non-traditional machining process that is extensively in use to machine the components having intricate profiles and shapes. In WEDM, it is very important to select the optimal process parameters so as to enhance the machine performance. This paper emphasizes the selection of optimal parametric combination of WEDM process while machining on EN31 steel, using grey-fuzzy logic technique. Process parameters such as servo voltage, wire tension, pulse-on-time and pulse-off-time were considered while taking into account several multi-responses such as material removal rate (MRR) and surface roughness (SR). It was found that pulse-on-time of 115 µs, pulse-off-time of 35 µs, servo voltage of 40 V and wire tension of 5 kgf results in a larger value of grey fuzzy reasoning grade (GFRG) which tends to maximize MRR and improve SR. Finally, analysis of variance (ANOVA) is applied to check the influence of each process parameters in the estimation of GFRG.


Author(s):  
Murali M. Sundaram ◽  
Sridevi Billa ◽  
Kamlakar P. Rajurkar

Drilling a micro hole with an aspect ratio above 10 is a challenging task for any-micromachining process. In micro electro discharge machining (micro EDM), a proven metallic micromachining process, this is due to the problems associated with debris removal. In such cases, where the capabilities of existing macro machining methods are constantly being challenged, innovative micro manufacturing approaches are required to make progress. Hybrid micromachining is one such approach in which the synergy of constituent processes is exploited to achieve desired results. In this paper, the results of ultrasonic vibration assisted micro electro discharge machining process are presented. This hybrid process is capable of deep hole drilling with aspect ratio of 20 in austenitic stainless steel by overcoming the limitations in the debris removal faced in the typical micro EDM process. Other benefits of ultrasonic vibration are the savings in machining time, and less tool wear. It is also noticed that the ultrasonic vibration causes some shape distortion and produces rougher machined surface.


Author(s):  
Murali Meenakshi Sundaram ◽  
Yakup Yildiz ◽  
K. P. Rajurkar

Cryogenic treatment is a heat treatment process in which the specimen is subjected to an extremely low temperature of the order of −300° F and below, to cause beneficial changes in the material properties. The advantages of cryogenic treatment include relieved residual stresses, and better electrical properties. Electro discharge machining (EDM) is a well known nontraditional machining process in which electrical energy is converted to thermal energy to remove material by melting and evaporation from electrically conductive materials. The process performance of EDM is affected by several factors including the material properties. In this study, the effect of cryogenic treatment on the performance of EDM is investigated experimentally. Copper tool electrodes were subjected to two different treatment methods, namely cold treatment (around −150° F) and deep cryogenic treatment (around −300° F). Using these electrodes, experiments were conducted to study the effect of various process parameters. Significant improvement in material removal rate was observed for EDM with cryogenically treated tools. However, their effect on tool wear is only marginal.


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