Study on Discharge Characteristics of Piezoelectric Self-Adaptive Micro-EDM System

2010 ◽  
Vol 34-35 ◽  
pp. 492-496 ◽  
Author(s):  
Yu Jie Zhu ◽  
Qin He Zhang ◽  
Xiu Zhuo Fu ◽  
Guang Hua Bao

A new technology of piezoelectric self-adaptive micro electrical discharge machining has been developed in this paper according to the characteristics of micro-EDM. Its working principle and the discharge characteristics are introduced, and it has been proved that the new technology can achieve micro machining. Using piezoelectric actuator as micro-feed mechanism, this new technology is simple in structure and can improve the discharging gap effectively. The discharge frequency and effective pulse utilization rate of the power supply is enhanced in machining. Experimental results show that this new technology can achieve good results.

2010 ◽  
Vol 143-144 ◽  
pp. 1434-1438
Author(s):  
Xiu Zhuo Fu ◽  
Qin He Zhang ◽  
Guang Hua Bao ◽  
Yu Jie Zhu

Micro electrical discharge machining (micro-EDM) has some shortcomings such as poor material removal rate (MRR) and high electrode wear ratio (EWR) etc, in order to overcome these demerits, a new piezoelectric self-adaptive micro-EDM, based on inverse piezoelectric effect, was developed in this paper. The structure and working principle of this new technology are different from traditional micro-EDM. Piezoelectric actuator used as the micro driven mechanism and it is simple. This new technology can realize self-elimination in the working process because of its special structure. Working principles and process of the new system were analyzed in this paper. The effect of parameters such as voltage, capacitance, and resistance on MRR, EWR and surface roughness was analyzed. Statistical analyses of the results show that voltage, capacitance significantly influence MRR, EWR and surface roughness. Resistance R1 and R2 has much influence on MRR and relative small effect on EWR and surface roughness.


2020 ◽  
Vol 191 ◽  
pp. 04004
Author(s):  
Kan Wang ◽  
Yong Liu

In micro electrical discharge machining (micro-EDM), polarity effect is attributed to the difference in energy distribution into the anode and cathode. Understanding the effect of machining polarity on energy distribution bears significance in predicting and controlling machining performances. Single discharge experiments were conducted in this study, to explore single discharge characteristics. The plasma radius and energy distribution were calculated by combining the crater size and the electro-thermal model. The results show that the influence of discharge current on crater depth-to-diameter ratio (H/D) is not significant with positive polarity. The plasma radius, fraction of energy transferred to workpiece, and crater size are greater for micro-EDM with negative polarity than positive polarity.


Micromachines ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 55 ◽  
Author(s):  
Qingyu Liu ◽  
Qinhe Zhang ◽  
Min Zhang ◽  
Fazhan Yang

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.


Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 718 ◽  
Author(s):  
Qingyu Liu ◽  
Qinhe Zhang ◽  
Min Zhang ◽  
Fazhan Yang

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.


2011 ◽  
Vol 462-463 ◽  
pp. 1092-1096 ◽  
Author(s):  
Muslim Mahardika ◽  
Gunawan Setia Prihandana ◽  
Takashi Endo ◽  
Suyitno ◽  
B. Arifvianto ◽  
...  

The important thing in micro-machining is its accuracy. The Micro-Electrical Discharge Machining (micro-EDM) is a promising method in micro-machining, because (1) the process is independent on the hardness of the workpiece but only depends on its thermal conductivity and melting point and (2) it can be used to machine materials with highly complex geometrical shapes using a simple-shaped tool electrode. However, the process in micro-EDM is not totally well-known, especially related to the formation of discharge pulse energy and the fracture phenomena. In the micro-EDM processes, the formation of discharge pulse energy is a complex phenomenon, since it is related to many parameters such as discharge gap, charge voltage, capacitance, and tool electrode wear. In this paper, the Acoustic Emission (AE) sensor is used to detect the changes of discharge pulse energy during machining of brass using micro-EDM. The results shows that the AE signals can detect and explain the fracture phenomena during the micro-EDM processes.


2020 ◽  
Vol 13 (3) ◽  
pp. 219-229
Author(s):  
Baocheng Xie ◽  
Jianguo Liu ◽  
Yongqiu Chen

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.


2013 ◽  
Vol 652-654 ◽  
pp. 1157-1162
Author(s):  
Fu Qiang Hu ◽  
Jian Fei Sun ◽  
Jun Qi Wei ◽  
Yong Zhang ◽  
Yan Dong Jia ◽  
...  

This paper researches the material erosion mechanisms of high silicon- aluminum (Si-Al) alloy in micro electrical discharge machining (Micro-EDM). By using Quanta 200F environment scanning electron microscope, the microstructure of Al-50wt%Si alloy by spray forming was observed. And a simplified model of high Si-Al alloy was set up. The Al-50wt%Si alloy was machined by using copper electrode and tungsten electrode respectively. And the differences of surface morphologies and element energy spectrum were compared. The process and the material erosion mechanisms of high Si-Al alloy in Micro-EDM were analyzed in detail. The results may provide theoretical basis for Micro-EDM of high Si-Al alloy.


2013 ◽  
Vol 549 ◽  
pp. 503-510 ◽  
Author(s):  
Gianluca D'Urso ◽  
Giancarlo Maccarini ◽  
C. Merla

The recent miniaturization trend in manufacturing, has enhanced the production of new and highly sophisticated systems in various industrial fields. In recent years, machining of the so called difficult to cut materials has become an important issue in several sectors. Micro Electrical Discharge Machining (micro-EDM) thanks to its contactless nature, is one of the most important technologies for the machining of this type of materials and it can be considered as one of the most promising manufacturing technologies for the fabrication of micro components. One of the most relevant applications of micro-EDM is micro-drilling. Micro holes in fact, are widely used for example in micro-electromechanical systems (MEMS), serving as channels or nozzles to connect two micro-features, and in micro-mechanical components. The present study is about micro drilling of metal plates by means of micro-EDM technology. In particular, the aim of this work is to investigate the effects of the downsizing of the micro holes diameter on the drilling performances. The influence of the reduction of the diameters in terms of both process performances (e.g., tool wear, taper rate, diametrical overcut) and general quality of the holes was investigated. Steel plates having thickness equal to 0.8 mm were taken into account. The drilling process was carried out using a micro-EDM machine Sarix SX 200 with carbide electrodes having diameter equal to 300, 200, 100 and 50 μm. Since the standard electrodes adopted in this study had a diameter equal to 300 μm, a wire EDM unit was used to obtain the other electrodes. The relationship between the process parameters considered the most significant and the final output, was studied. Furthermore, the geometrical and dimensional properties of the micro-holes were analyzed using both optical and scanning electron microscopes. In particular, it is demonstrated that the diameter size has a significant influence on the final value of the diametrical overcut while peak current and frequency parameters have a negligible effect.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6074
Author(s):  
Tingting Ni ◽  
Qingyu Liu ◽  
Zhiheng Chen ◽  
Dongsheng Jiang ◽  
Shufeng Sun

Micro electrical discharge machining (micro EDM) is able to remove conductive material by non-contact instantaneous high temperature, which is more suitable for machining titanium and its alloys compared with traditional machining methods. To further improve the machining efficiency and machined surface quality of micro EDM, the nano particle surfactant mixed micro EDM method is put forward in this paper. Experiments were conducted to explore the effect of nano particle surfactant on the micro EDM performance of titanium alloy. The results show that the material removal rate of micro EDM in dielectric mixed with TiO2 is the highest when open-circuit voltage is 100 V, followed by Al2O3 and ZrO2. Lower tool wear rate can be produced by using dielectric mixed with nano particle surfactant. The taper ratio of micro EDM in dielectric mixed with nano particle surfactant is higher than that in deionized water. The surface roughness Ra of micro EDM in dielectric mixed with TiO2 can be 50% lower than that in deionized water. It is helpful to improve the machining performance by adding surface surfactant in the dielectric of micro EDM.


2008 ◽  
Vol 375-376 ◽  
pp. 303-307
Author(s):  
Zhen Long Wang ◽  
Wei Liang Zeng ◽  
Qiang Gao

Micro electrical discharge machining (EDM) with block electro discharge grinding (BEDG), is explored and assessed as a method for developing micro electrode, for wire electro discharge grinding (WEDG) has shortcoming of low working efficiency, especially in the case of micro machining. For fabricating micro electrode by BEDG, mechanics of initial clamping errors are analyzed, the technology of electrode movement is proposed to compensate the clamping errors and control the finish size of micro electrodes. On the basis of a great deal of experiments, the effect of working voltage on machining efficiency has been found out and been analyzed theoretically, threshold value of working voltage is determined to be about 30V.As shown by result with the technology, at a high machining speed, the minimum diameter of micro electrodes reaches 3*m, its slenderness ratio is more than 5.


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