Effect of Micro-EDM on Diameter Consistency of Micro-Hole Arrays

2014 ◽  
Vol 609-610 ◽  
pp. 1489-1493
Author(s):  
Guo Zheng Zhu ◽  
Ji Cheng Bai ◽  
Yong Yi Huang

The inkjet template is an important part of digital printing equipment. The diameter of hole arrays on the template determines the consistency of the ink droplet and thus affects print quality. To improve the printing performance of digital printing equipment, this study investigated the effect of micro-electrical discharge machining (micro-EDM) on the diameter consistency of micro-hole arrays on an inkjet template. Combining block electrical discharge grinding and wire electrical discharge grinding enabled the online processing of the fine tool electrode, whose diameter can be stably controlled at less than 45 μm, whose maximum diameter deviation was about 1 μm. The tool electrode can also be used to process micro-hole arrays. Subsequently, the relationship between the discharge energy of micro-EDM and the erosion material was theoretically analyzed, as was the effects of the diameter consistency of the micro-electrode itself on that of the micro-hole array processed by the micro-electrode and the relationship between processing parameters and the discharge gap between the micro-electrode and the workpiece. Experimentations were conducted on the effect of the flow rate, flush angle, and rotation speed of the electrode and the resistivity of de-ionized water to the diameter consistency of the micro-hole arrays. On the optimized parameters, a 16×16 micro-hole array with a diameter deviation of less than 2 μm was successfully processed, and the average diameter of the holes, about 44 μm, was used for the inkjet template. Beside, an electrode with a diameter of 14μm is also machined and it was used to process a 8×8 micro-hole array, whose diameter deviation is 0.9μm and average diameter is less than 20μm. Large number of experiments show that by the proposed method, one electrode can stably machined 800 holes with diameter less than 50μm, and their diameter deviation is less than 3μm. ​The digital printing equipment with these holes can meet the current demand for components with micro-hole arrays.

CIRP Annals ◽  
1999 ◽  
Vol 48 (1) ◽  
pp. 127-130 ◽  
Author(s):  
D.M. Allen ◽  
H.J.A. Almond ◽  
J.S. Bhogal ◽  
A.E. Green ◽  
P.M. Logan ◽  
...  

Author(s):  
Guanxin Chi ◽  
Weiliang Zeng ◽  
Desheng Dong ◽  
Zhenlong Wang

Micro electrical discharge machining (EDM), enhanced with ultrasonic vibration, is explored and assessed as a new technology for developing microelectrode array, for microelectrode array fabricated by LIGA has shortcomings such as complex technology and high price. Based on the mechanism of micro-EDM, micro-hole array discharges to fabricate microelectrode array by reverse copying. In the process of reverse copying, the thicker rod electrode can’t rotate, resulting in electric arc and short-circuit easily, so it is necessary to add ultrasonic vibration on the plane plate electrode. According to the technology, a set of micro-EDM system is designed and developed. On the machining system, influence of ultrasonic vibration is analysed from the way of vibration mechanics through theoretical analysis and experimental observation. Compared with machining without ultrasonic vibration, single discharging energy decreases 1/2, discharge frequency improves three times, machining efficiency increases two times and better surface quality is achieved. Finally, 5×5 arrays of microelectrode and microhole made by these microelectrode arrays are got, the diameter of single electrode is less than 30μm and height-to-width aspect ratio is more than 8, moreover these arrays of microelectrode and micro-hole have very good surface quality.


2009 ◽  
Vol 69-70 ◽  
pp. 79-82 ◽  
Author(s):  
Yu Kui Wang ◽  
Zhen Long Wang ◽  
Mao Sheng Li ◽  
Wei Liang Zeng ◽  
M.H. Weng

In the paper, in order to overcome machining limits in throughput and precision because of positioning error and tool wear of a single tool electrode, a method for the microelectrode array fabrication by micro-WEDM is described and assessed. Characteristics of the microelectrode array fabrication by micro-WEDM, such as machining open voltage, pulse peak current, discharge duration and servo feed rate so on, are investigated through a series of experiments. A 10 10 squared electrode array is machined by micro-WEDM and the width of each squared electrode is about 40µm. The microelectrode array with good quality is obtained by applying decreased open voltage and peak current, increased discharge duration and optimized machining speed. Then micro hole-array is processed by applying obtained electrode array in micro-EDM method. The diameter of each squared hole in the array is about 50 µm due to appropriate control strategy that per micro pulse energy is decreased and periodic jump-down is applied during the machining process. Experiments have demonstrated that the combination process of microelectrode array fabricated by micro-WEDM and micro-hole array done by micro-EDM is a novel method of process which makes it more feasible and efficient to fabricate microelectrode array and high-density hole-array.


2017 ◽  
Vol 64 (2) ◽  
pp. 149-163 ◽  
Author(s):  
Govindan Puthumana

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.


2005 ◽  
Vol 475-479 ◽  
pp. 1337-1340
Author(s):  
Chien Cheng Liu ◽  
Jow Lay Huang

Conductive TiN/Si3N4 ceramic composites were processed by electrical discharge machining (EDM) and their microstructure and conductivity investigated. A low electrical resistivity of 1.25×10-3Ω.cm was obtained in 40vol%TiN/Si3N4 composite. The whole process of tool electrode wear is evaluated by sinker-EDM. The machined surfaces of TiN/Si3N4 ceramic composites were examined by scanning electron microscopy (SEM) and profilometry to determine the surface finish. Micropores of 700µm in depth and 70µm in diameter were successfully machined in TiN/ Si3N4 composites by the micro-EDM method.


Author(s):  
G. Kibria ◽  
I. Shivakoti ◽  
B. Bhattacharyya

In micro-electrical discharge machining (micro-EDM), dielectric plays a significant role during the machining process as different types of dielectrics encounters different chemical compositions, cooling rates and dielectric strengths. Therefore, while employing these different dielectrics, dissimilar process responses are accounted when machining in EDM at micron level. The present paper investigates micro-EDM characteristics such as material removal rate (MRR), tool wear rate (TWR), overcut (OC), taperness and machining time (MT) during micro-machining of through holes on Ti-6Al-4V superalloy employing de-ionized water based dielectric other than conventional hydro-carbon oil i.e. kerosene. The paper also includes the comparative study of the micro-EDM machining characteristics employing boron carbide (B4C) powder as additive in de-ionized water dielectric at different discharge energies. The results show that MRR and taper of micro-hole are better and TWR is less employing B4C additive in the dielectric than pure one, i.e. the productivity is improved and same micro-tool can be used for machining an array of micro-holes. Surface topography and recast layer formed during micro-hole machining by micro-EDM has also been investigated based on optical and SEM micrographs. Energy dispersive spectroscopy (EDS) analysis of machined surface as well as tool electrode surface has been done and the results show that there is significant amount of infusion of tungsten element onto the machined surface. A significant amount of carbon element is found onto the tool electrode surface.


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