Microelectrode Array Fabrication by Micro-WEDM

2009 ◽  
Vol 69-70 ◽  
pp. 79-82 ◽  
Author(s):  
Yu Kui Wang ◽  
Zhen Long Wang ◽  
Mao Sheng Li ◽  
Wei Liang Zeng ◽  
M.H. Weng
Keyword(s):  
Microelectrode Array ◽  
Electrode Array ◽  
Machining Process ◽  
Hole Array ◽  
Micro Edm ◽  
Peak Current ◽  
Micro Hole ◽  
Discharge Duration ◽  
Micro Wedm ◽  
Array Fabrication

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.

Experimental Study of Microelectrode Array and Micro-Hole Array Fabricated by Ultrasonic Enhanced Micro-EDM

2007 ◽  
Vol 364-366 ◽  
pp. 482-487 ◽  
Author(s):  
Wei Liang Zeng ◽  
Yan Ping Gong ◽  
Ying Liu ◽  
Zhen Long Wang
Keyword(s):  
Experimental Study ◽  
Ultrasonic Vibration ◽  
Microelectrode Array ◽  
Machining Process ◽  
High Price ◽  
Hole Array ◽  
Micro Edm ◽  
Mean Square ◽  
Mean Square Deviation ◽  
Micro Hole

Micro electrical discharge machining (EDM), enhanced with ultrasonic vibration, is explored and assessed as a method 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 not rotate, resulting in electric arc and short-circuit occurring easily, so it is necessary to add ultrasonic vibration on the plane plate electrode, in order to exclude debris as soon as possible and stabilize machining process. In the process of machining, four parameters, such as working voltage, working capacity, ultrasonic amplitude and holes spacing, are important to machining efficiency, each parameter has four typical values. In order to reduce experiment times, a scheme of orthogonal experiment was designed with different parameters combination. With result of experiments, the ratio of mean square deviation to error mean square deviation of each parameter was calculated and significance of each parameter was obtained, and the best parameters combination was asserted through theoretical calculation. Also, experimental study of using microelectrode array to machine micro-hole array by Micro- EDM was made and influence curve of each parameter was drawn. Finally, 5×5 arrays of microelectrode were obtained, the diameter of single electrode is less than about 30.m and heightto- width aspect ratios is more than 8, moreover, these microelectrode arrays have good coaxiality and surface quality.

Key Technology of Microelectrode Array Fabrication by Ultrasonic Enhanced Micro-EDM

2007 ◽  
Author(s):  
Guanxin Chi ◽  
Weiliang Zeng ◽  
Desheng Dong ◽  
Zhenlong Wang
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Microelectrode Array ◽  
Electrical Discharge Machining ◽  
Short Circuit ◽  
High Price ◽  
Hole Array ◽  
Micro Edm ◽  
Plane Plate ◽  
Micro Hole

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.

Experimentation and Analysis into Micro-Hole Machining of Ti-6Al-4V by Micro-EDM Using Boron Carbide Powder Mixed De-Ionized Water

2014 ◽  
Vol 4 (1) ◽  
pp. 22-41 ◽  
Author(s):  
G. Kibria ◽  
I. Shivakoti ◽  
B. Bhattacharyya
Keyword(s):  
Boron Carbide ◽  
Electrode Surface ◽  
Machining Process ◽  
Carbide Powder ◽  
Chemical Compositions ◽  
Tool Electrode ◽  
Micro Edm ◽  
Machined Surface ◽  
Micro Hole ◽  
Hole Machining

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.

Duplication Error and Repeated Error Analysis of Micro-Hole Array Fabrication by EMM

2010 ◽  
Vol 113-116 ◽  
pp. 1914-1917
Author(s):  
Ying Liu ◽  
Wei Liang Zeng ◽  
Zhen Long Wang
Keyword(s):  
Electric Field ◽  
Electrochemical Micromachining ◽  
Impact Factors ◽  
Hole Array ◽  
Machining Accuracy ◽  
Root Cause ◽  
Micro Hole ◽  
The Impact ◽  
Corner Turning ◽  
Array Fabrication

In the process of Electrochemical micromachining (EMM), the machining gap between tool cathode and workpiece anode is the root cause leading to the error, EMM error of Micro-hole array can be divided into duplication error and repeated error. According to the characteristics of EMM, the impact factors of micro-hole array duplication error and repeated error are analyzed. The distribution of electric field strength and scattered erosion are the most important causation resulting in duplication error. There is stray electric-field existing on electrode side, making scattered erosion to workpiece, impacting micro-hole forming processing precision, the extent of scattered erosion becomes serious with processing time growing, that is showed as phenomenon of sharp corner turning round and the phenomenon is observed carefully by experiments. While the accumulation of air bubbles in the processing region leads to the emergence of repeated error. Through theoretical and experimental analysis, measures are taked to improve machining accuracy.

Study on Machining Characteristics of Ultrasonic Vibration Assisted Micro-EDM

2012 ◽  
Vol 217-219 ◽  
pp. 2163-2166 ◽  
Author(s):  
Tomohiko Ichikawa ◽  
Wataru Natsu
Keyword(s):  
Ultrasonic Vibration ◽  
Machining Process ◽  
Hole Drilling ◽  
Micro Edm ◽  
Discharge Energy ◽  
Machining Speed ◽  
Micro Hole ◽  
Short Circuits ◽  
Small Discharge ◽  
Machining Characteristics

The existence of debris in the inter-electrode area in micro-EDM interrupts the machining process. Applying ultrasonic vibration to the machining fluid helps circulate the machining fluid and remove the debris from the gap area, and thus reduce short-circuits and abnormal discharges. In this study, the effect of applying ultrasonic vibration to machining fluid in micro-EDM was experimentally investigated. It was found that a significant increase in the machining speed was realized by applying ultrasonic vibration. Also, with the vibration of the machining fluid, micro-hole drilling with ultra-small discharge energy became possible.

scholarly journals Precision EDM of Micron-Scale Diameter Hole Array Using in-Process Wire Electro-Discharge Grinding High-Aspect-Ratio Microelectrodes

Micromachines ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 17
Author(s):  
Zhixiang Zou ◽  
Zhongning Guo ◽  
Qinming Huang ◽  
Taiman Yue ◽  
Jiangwen Liu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Turbine Blades ◽  
Hole Array ◽  
Machining Accuracy ◽  
Micro Edm ◽  
Wire Vibration ◽  
Micro Hole ◽  
The Wire

Micro-electrical discharge machining (micro-EDM) is a good candidate for processing micro-hole arrays, which are critical features of micro-electro-mechanical systems (MEMS), diesel injector nozzles, inkjet printheads and turbine blades, etc. In this study, the wire vibration of the wire electro-discharge grinding (WEDG) system has been analyzed theoretically, and, accordingly, an improved WEDG method was developed to fabricate micron-scale diameter and high-aspect-ratio microelectrodes for the in-process micro-EDM of hole array with hole diameter smaller than 20 μm. The improved method has a new feature of a positioning device to address the wire vibration problem, and thus to enhance microelectrodes fabrication precision. Using this method, 14 μm diameter microelectrodes with less than 0.4 μm deviation and an aspect ratio of 142, which is the largest aspect ratio ever reported in the literature, were successfully fabricated. These microelectrodes were then used to in-process micro-EDM of hole array in stainless steel. The effects of applied voltage, current and pulse frequency on hole dimensional accuracy and microelectrode wear were investigated. The optimal processing parameters were selected using response–surface experiments. To improve machining accuracy, an in-process touch-measurement compensation strategy was applied to reduce the cumulative compensation error of the micro-EDM process. Using such a system, micro-hole array (2 × 80) with average entrance diameter 18.91 μm and average exit diameter 17.65 μm were produced in 50 μm thickness stainless steel sheets, and standard deviations of hole entrance and exit sides of 0.44 and 0.38 μm, respectively, were achieved.

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