scholarly journals A Study of a PID Controller Used in a Micro-Electrical Discharge Machining System to Prepare TiO2 Nanocolloids

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1044 ◽  
Author(s):  
Kuo-Hsiung Tseng ◽  
Yur-Shan Lin ◽  
Chaur-Yang Chang ◽  
Meng-Yun Chung

This study developed a micro-electrical discharge machining (micro-EDM) system for producing TiO2 nanocolloids. When a proportional–integral–derivative controller designed using the Ziegler–Nichols method was adopted to control the interelectrode gap, TiO2 nanocolloids were obtained from spark discharges generated between two titanium wires immersed in deionized water. For a pulse on time–off time of 40–40 μs and a colloid production time of 100 min, TiO2 nanocolloids were produced that had an absorbance of 1.511 at a wavelength of 245 nm and a ζ potential of −47.2 mV. They had an average particle diameter of 137.2 nm, and 64.2% of particles were smaller than 91.28 nm. The minimum particles were spherical. The characteristics of colloids confirmed that the micro-EDM system can produce TiO2 nanocolloids with excellent suspension stability. The colloid production method proposed in this study has the advantages of low equipment cost and no dust diffusion in the process environment. These advantages can improve the competitiveness of the electric spark discharge method for high-quality TiO2 nanoparticle production. The colloids produced in this study did not contain elements other than titanium and oxygen, and they may prevent secondary environmental pollution.

2009 ◽  
Vol 69-70 ◽  
pp. 177-181
Author(s):  
Zi Long Peng ◽  
Zhen Long Wang ◽  
Ying Huai Dong ◽  
Hui Chen

Based on the principle of micro electrical discharge machining (EDM), a reversible machining method is proposed, which can achieve depositing or removing selectively metal material for the fabrication of micro structures. It is easy to transform the machining process from deposition to removal in one machining system. The characteristics of the deposited material show that the components of deposited material are almost the same as those of the tool electrode, and the metallurgical bonding has formed on the interface between the deposited material and the base. Moreover, the deposited material has well machinability in different micro EDM selective removal process, including micro EDM die-sinking and micro EDM milling. As a result, a micro square column with 0.1mm in side length, 0.88mm in height and a micro cylinder with 0.14mm in diameter, 1.18mm in height were fabricated by using the micro reversible EDM process.


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.


Mechatronics ◽  
2021 ◽  
Vol 79 ◽  
pp. 102649
Author(s):  
Kuo-Hsiung Tseng ◽  
Kuo-Hui Chen ◽  
Chaur-Yang Chang ◽  
Yagus Cahyadi ◽  
Meng-Yun Chung

Author(s):  
P. C. Tan ◽  
S. H. Yeo

The thickness of recast layers produced during electrical discharge machining (EDM) is an important process performance measure as it may indicate an extent of crack propagation in a machined surface or thickness of a functional layer alloyed onto a machined surface. Thus, the availability of the recast layer thickness prediction models is needed to allow better control of machining outcomes, which becomes more vital for micro-EDM due to the microscale of machined features. The proposed numerical model, based on a multiple discharge approach for recast layer prediction, is developed to fill an existing gap in micro-EDM. The multiple discharge approach accounts for the overlapping nature by which craters are generated on the machined surface and considers the recast layer to be a combination of individual recast regions from individual craters. The numerical analysis, based on finite element methods, is used to determine the melting isotherms due to heat inputs on overlapping crater profiles. Then, a hemispherical-capped crater profile is estimated by applying a recast plasma flushing efficiency to the amount of molten material bounded by the melting isotherm. Finally, the recast region is defined to be bounded by the melting isotherm and crater profile. The model, developed for a peak discharge current of 1.45 A and pulse on time between 166 ns and 606 ns, predicted recast layer thicknesses of between 1.0 μm and 1.82 μm. It is then validated at pulse on time settings of 244 ns and 458 ns, which generated average recast layer thicknesses of 1.18 μm and 1.56 μm, respectively. Thus, the numerical model developed using the multiple discharge approach is suitable for estimation of recast layer thicknesses in micro-EDM.


2012 ◽  
Vol 472-475 ◽  
pp. 2401-2404 ◽  
Author(s):  
Guo Zheng Zhu ◽  
Ji Cheng Bai ◽  
Yong Feng Guo ◽  
Peng Ju Hou ◽  
Chao Jiang Li

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


2015 ◽  
Vol 651-653 ◽  
pp. 759-764
Author(s):  
Oliver Kröning ◽  
Mathias Herzig ◽  
Matthias Hackert-Oschätzchen ◽  
Ralf Kühn ◽  
Henning Zeidler ◽  
...  

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.


2011 ◽  
Vol 411 ◽  
pp. 315-318 ◽  
Author(s):  
Lan Chen

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.


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