scholarly journals Study on the Time-Varying Characteristics of Discharge Plasma in Micro-Electrical Discharge Machining

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 718 ◽  
Author(s):  
Qingyu Liu ◽  
Qinhe Zhang ◽  
Min Zhang ◽  
Fazhan Yang
Keyword(s):  
Discharge Current ◽  
Electrical Discharge ◽  
Discharge Plasma ◽  
Electrical Discharge Machining ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Expansion Velocity ◽  
Micro Edm ◽  
Micro Electrical Discharge Machining ◽  
Discharge Duration

Micro electrical discharge machining (micro-EDM) has been widely applied in the field of precision machining, but the machining mechanism is still unclear. In this paper, the relationship between the characteristics of discharge plasma and discharge duration is clarified by analyzing the formation and expansion process of the discharge plasma channel under micro-scale discharge conditions. Based on the experimental results, the effects of discharge duration on the discharge current, discharge voltage and discharge crater size are discussed. The results show that the expansion acceleration, internal pressure, temperature, and electron density of the discharge plasma decrease as the discharge duration increase, while the radius and expansion velocity of the discharge plasma increase, and finally the discharge plasma reaches the state of shape–position equilibrium. The resistance of discharge plasma is estimated to fluctuate in the range of 38–45 Ω by the ratio of discharge maintenance voltage to discharge current. The energy utilization rate of micro-EDM is very high when discharge duration is less than 4 μs, and then decreases gradually as the discharge duration increased. There is a positive linear relationship between discharge crater volume and discharge duration. The discharge duration has no significant effect on the discharge crater depth. This study provides a theoretical basis for further study of discharge plasma characteristics in micro-EDM.

scholarly journals Study on the Discharge Characteristics of Single-Pulse Discharge in Micro-EDM

Micromachines ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 55 ◽  
Author(s):  
Qingyu Liu ◽  
Qinhe Zhang ◽  
Min Zhang ◽  
Fazhan Yang
Keyword(s):  
Electrical Discharge Machining ◽  
Short Pulse ◽  
Pulse Discharge ◽  
Single Pulse ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Micro Edm ◽  
Discharge Characteristics ◽  
Discharge Duration ◽  
Positive Ion

To further study the discharge characteristics and machining mechanism of micro-electrical discharge machining (micro-EDM), the variation trends of the discharge energy and discharge crater size with actual discharge duration are discussed based on single-pulse experiments. The polarity effect of micro-EDM was analyzed according to the motion characteristics of electrons and ions in the discharge plasma channel. The results show that the discharge current and voltage of micro-EDM were independent of the discharge width and open-circuit voltage. The energy utilization rate of the short-pulse discharge was relatively high, and the energy utilization rate decreased gradually as the discharge duration increased. Even if the mass of the positive ion was much larger than that of the electron, the kinetic energy of the positive ion was still less than that of the electron when bombarding the surface of the electrode. The acceleration and speed of electrons were very high, and the number of times that electrons bombarded the surface of positive electrode was more than 600 times that of positive ions bombarding the surface of the negative electrode during the same time.

Recent Patents on Micro-EDM Milling

2020 ◽  
Vol 13 (3) ◽  
pp. 219-229
Author(s):  
Baocheng Xie ◽  
Jianguo Liu ◽  
Yongqiu Chen
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Three Dimensional ◽  
Processing Method ◽  
Electrode Wear ◽  
Micro Edm ◽  
Processing Efficiency ◽  
Processing Methods ◽  
Machining Quality ◽  
Micro Electrical Discharge Machining

Background: Micro-Electrical Discharge Machining (EDM) milling is widely used in the processing of complex cavities and micro-three-dimensional structures, which is a more effective processing method for micro-precision parts. Thus, more attention has been paid on the micro-EDM milling. Objective : To meet the increasing requirement of machining quality and machining efficiency of micro- EDM milling, the processing devices and processing methods of micro-EDM milling are being improved continuously. Methods: This paper reviews various current representative patents related to the processing devices and processing methods of micro-EDM milling. Results: Through summarizing a large number of patents about processing devices and processing methods of micro-EDM milling, the main problems of current development, such as the strategy of electrode wear compensation and the development trends of processing devices and processing methods of micro-EDM milling are discussed. Conclusion: The optimization of processing devices and processing methods of micro-EDM milling are conducive to solving the problems of processing efficiency and quality. More relevant patents will be invented in the future.

Research on Micro EDM Machine Tool for Machining Micro Array Holes

2012 ◽  
Vol 472-475 ◽  
pp. 2401-2404 ◽  
Author(s):  
Guo Zheng Zhu ◽  
Ji Cheng Bai ◽  
Yong Feng Guo ◽  
Peng Ju Hou ◽  
Chao Jiang Li
Keyword(s):  
Machine Tool ◽  
Electrical Discharge ◽  
Pulse Generator ◽  
Electrical Discharge Machining ◽  
Micro Edm ◽  
Generator System ◽  
Micro Nozzle ◽  
Micro Electrical Discharge Machining ◽  
Micro Array ◽  
New Type

As demands for the micro array holes in modern industry and the characteristics of micro Electrical Discharge Machining (micro EDM), a new type micro EDM machine tool used to machine micro array holes was designed and manufactured. The machine tool contains following systems: the mechanism system, the control system, the pulse generator system and other auxiliary systems. Each system was studied respectively. Base on a large number of experiments, finally, a sample with 256 array holes was processed by the machine tool. The diameter of single hole is 45µm and precision of the holes is ±1µm. The sample has been successfully applied to R & D test of micro nozzle components

Micro Electrical Discharge Machining of Tungsten Carbide with Ultra-Short Pulse

2015 ◽  
Vol 651-653 ◽  
pp. 759-764
Author(s):  
Oliver Kröning ◽  
Mathias Herzig ◽  
Matthias Hackert-Oschätzchen ◽  
Ralf Kühn ◽  
Henning Zeidler ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Pulse Generator ◽  
Electrical Discharge Machining ◽  
Short Pulse ◽  
High Surface ◽  
Micro Edm ◽  
High Surface Quality ◽  
Micro Electrical Discharge Machining ◽  
Metal Machining ◽  
Ultra Short Pulse

Micro EDM (Electrical Discharge Machining) is a known nonconventional process for the machining of hard to cut materials. Due to its ablating nature based on melting and evaporation through heat induced by electrical discharges, it can function independently of the hardness, toughness or brittleness of the workpiece. Thus micro EDM is a possible process to fulfill the requirements of higher precision and high quality in carbide metal machining. Thereby the surface and the roughness of machined carbide metals depend on the discharge energy used. For machining carbide metals with high surface quality pulse generators with ultra-short discharges are required. This paper presents the development of a two-staged pulse generator with the ability to provide ultra-short pulses by using a two-staged pulse. The current and voltage signals of the discharges were recorded and their characteristics were analyzed.

Research the Molybdenum Alloy Micro EDM Micro-Holes

2011 ◽  
Vol 411 ◽  
pp. 315-318 ◽  
Author(s):  
Lan Chen
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Molybdenum Alloy ◽  
Micro Edm ◽  
Traditional Methods ◽  
Micro Electrical Discharge Machining ◽  
Micro Holes ◽  
On Line ◽  
Better Than

In the field of micromachining, micro electrical discharge machining (MEDM) is an important and perfect machining method for high rigid or high wearable materials, which is better than traditional methods of machining. MEDM technology is used to manufacture on-line electrodes and then minimum micro shafts with diameter of 15μm were made with these electrodes. A series of different micro-holes (e.g. Φ40μm、Φ50μm、Φ60μm) on pieces of molybdenum were manufactured with different parameters. Wastage of electrode rule was also studied.

Study on the Effect of Nano and Micro MoS2 Powder in Micro-Electrical Discharge Machining

2011 ◽  
Vol 264-265 ◽  
pp. 1450-1455 ◽  
Author(s):  
Gunawan Setia Prihandana ◽  
Tutik Sriani ◽  
Kei Prihandana ◽  
Yuta Prihandana ◽  
Muslim Mahardika ◽  
...  
Keyword(s):  
Surface Quality ◽  
Material Removal Rate ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Micro Edm ◽  
Micro Electrical Discharge Machining ◽  
Powder Suspension ◽  
Size Powder

The application of powder mixed dielectric to improve the efficiency of electrical discharge machining (EDM) has been acknowledged extensively. However, the study of micro-size powder suspension in micro-EDM field is still limited. In this research, nano and micro size powder of MoS2 were used as catalyst agent. Powder suspension in different size was able to provide significant improvement in material removal rate and surface quality to increase the efficiency in μ- EDM processes.

scholarly journals An Influence of Parameters of Micro-electrical Discharge Machining on Wear of Tool Electrode

2017 ◽  
Vol 64 (2) ◽  
pp. 149-163 ◽  
Author(s):  
Govindan Puthumana
Keyword(s):  
Tool Wear ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Tool Electrode ◽  
Micro Edm ◽  
Modeling And Analysis ◽  
Micro Electrical Discharge Machining ◽  
Wear Ratio ◽  
Tool Wear Ratio ◽  
Main Effect

AbstractTo achieve better precision of features generated using the micro-electrical discharge machining (micro-EDM), there is a necessity to minimize the wear of the tool electrode, because a change in the dimensions of the electrode is reflected directly or indirectly on the feature. This paper presents a novel modeling and analysis approach of the tool wear in micro-EDM using a systematic statistical method exemplifying the influences of capacitance, feed rate and voltage on the tool wear ratio. The association between tool wear ratio and the input factors is comprehended by using main effect plots, interaction effects and regression analysis. A maximum variation of four-fold in the tool wear ratio have been observed which indicated that the tool wear ratio varies significantly over the trials. As the capacitance increases from 1 to 10 nF, the increase in tool wear ratio is by 33%. An increase in voltage as well as capacitance would lead to an increase in the number of charged particles, the number of collisions among them, which further enhances the transfer of the proportion of heat energy to the tool surface. Furthermore, to model the tool wear phenomenon, a regression relationship between tool wear ratio and the process inputs has been developed.

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