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.

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.

scholarly journals Experimental investigation of the electrochemical micromachining process of Ti-6Al-4V titanium alloy under the influence of magnetic field

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
T. Praveena Gopinath ◽  
J. Prasanna ◽  
C. Chandrasekhara Sastry ◽  
Sandeep Patil
Keyword(s):  
Magnetic Field ◽  
Titanium Alloy ◽  
Removal Rate ◽  
Electrochemical Machining ◽  
Machining Process ◽  
Electrochemical Micromachining ◽  
Machining Accuracy ◽  
Micro Hole ◽  
Neodymium Magnets ◽  
Pulse On Time

Abstract An attempt has been made to study the influence of magnetic field on the micro hole machining of Ti-6Al-4V titanium alloy using electrochemical micromachining (ECMM) process. The presence of magneto hydro dynamics (MHD) is accomplished with the aid of external magnetic field (neodymium magnets) in order to improve the machining accuracy and the performance characteristics of ECMM. Close to ideal solution for magnetic and nonmagnetic field ECMM process, the parameters used are as follows: concentration electrolyte of 15 g/l; peak current of 1.35 A; pulse on time of 400 s; and duty factor of 0.5. An improvement of 11.91–52.43% and 23.51–129.68% in material removal rate (MRR) and 6.03–21.47% and 18.32–33.09% in overcut (OC) is observed in ECMM of titanium alloy under the influence of attraction and repulsion magnetic field, respectively, in correlation with nonmagnetic field ECMM process. A 55.34% surface roughness factor reduction is ascertained in the hole profile in magnetic field-ECMM in correlation with electrochemical machined titanium alloy under nonmagnetic field environment. No machining related stress is induced in the titanium alloy, even though environment of electrochemical machining process has been enhanced with the presence of magnetic field. A slight surge in the compressive residual factor, aids in surge of passivation potential of titanium alloy, resulting in higher resistance to outside environment.

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.

Process Experimental Research of Micro-Hole in Electrochemical Micromachining by Nanosecond Pulse Current

2013 ◽  
Vol 764 ◽  
pp. 15-19
Author(s):  
Zhi Yong Li ◽  
Hong Li Liu ◽  
Zhi Peng Duan
Keyword(s):  
Pulse Current ◽  
Electrochemical Machining ◽  
Pulse Frequency ◽  
Electrochemical Micromachining ◽  
Machining Accuracy ◽  
Anode Dissolution ◽  
Micro Hole ◽  
Processing Accuracy ◽  
Hole Machining

Electrochemical micro-machining (ECMM) is a method that utilizes anode dissolution principle to process shaping. In the Electrochemical machining （ECM）of micro-hole, machining precision is an important aspect to measure machining quality of micro-hole. In this paper micro-hole machining is regarded as the research object, effects of many factors such as power supply natures, electrolyte composition, pulse width and pulse frequency on machining accuracy in micro-hole ECM have been evaluated. Research shows that processing accuracy can be improved through using non-linear electrolyte in high frequency, narrow pulse electrochemical machining.

A Measuring Method of Liquid Food Conductivity Based on Pulse Response Measurement Method

2014 ◽  
Vol 981 ◽  
pp. 628-631
Author(s):  
Xin Lao Wei ◽  
Yu Long LI
Keyword(s):  
Electric Field ◽  
Pulsed Electric Field ◽  
Measuring Method ◽  
Pulse Response ◽  
Impact Factors ◽  
Liquid Food ◽  
Stray Capacitance ◽  
Response Measurement ◽  
Response Method ◽  
The Impact

The food conductivity is one of impact factors on pulsed electric field sterilization. Abnormal breakdown of high conductivity liquid is also one of the bottlenecks in pulsed electric field sterilization technology. The conductivity of liquid food should be accurate calculated for searching the mechanism of abnormal breakdown deeply. An accurate measuring method of conductivity of liquid food is proposed based on pulse response method. Conductivity can be calculated by data recorded from oscilloscope with electrical pulse treating on the conductance cell. This method can decrease the impact of stray capacitance and polarization phenomenon on measured results.

Research on Electrochemical Micromachining System and Related Techniques

2006 ◽  
Vol 315-316 ◽  
pp. 731-735
Author(s):  
Xiao Hai Li ◽  
Zhen Long Wang ◽  
Wan Sheng Zhao
Keyword(s):  
Machine Tool ◽  
Electrical Discharge Machining ◽  
Short Pulse ◽  
Electrochemical Machining ◽  
Electrochemical Micromachining ◽  
Machining Accuracy ◽  
Tool Electrode ◽  
Micro Electrical Discharge Machining ◽  
Micro Hole ◽  
Micro Tool

Electrochemical machining (ECM) has been rarely applied in micromachining because the electric field is not localized. In order to explore the feasibility of applying ECM to micromachining at micro to meso-scale, an experimental setup with precision control over electrochemical micromachining (EMM) was developed, which is in fact a multifunctional machine tool. The micro tool electrodes for EMM can also be fabricated by micro electrical discharge machining (EDM) on the same machine tool. A high-frequency short-pulse micro-energy MOSFET power supply was designed. Lower machining voltage and lower concentration of passivity electrolyte are utilized together to localize dissolution area in EMM. A micro hole 45 ,m in diameter was drilled by EMM on stainless steel foil with 100 μm thickness. A new approach of fabricating microstructures by means of EMM milling using a simple micro tool electrode is proposed, and a shaped hole and a micro cantilever beam with high precision were acquired by EMM milling. The satisfactory process results indicate the potential capability of EMM for higher machining accuracy and smaller machining size.

The Impact of Anglicizing Former German-Language Psychology Journals on Authorship and Citation Frequencies

2012 ◽  
Vol 17 (3) ◽  
pp. 190-198 ◽  
Author(s):  
Günter Krampen ◽  
Thomas Huckert ◽  
Gabriel Schui
Keyword(s):  
Side Effects ◽  
English Language ◽  
General Trend ◽  
Native Language ◽  
Impact Factors ◽  
German Language ◽  
Journal Articles ◽  
Number Of Citations ◽  
The Impact ◽  
Number Of Authors

Exemplary for other than English-language psychology journals, the impact of recent Anglicization of five former German-language psychology journals on (1) authorship (nationality, i.e., native language, and number of authors, i.e., single or multiple authorships), (2) formal characteristics of the journal (number of articles per volume and length of articles), and (3) number of citations of the articles in other journal articles, the language of the citing publications, and the impact factors (IF) is analyzed. Scientometric data on these variables are gathered for all articles published in the four years before anglicizing and in the four years after anglicizing the same journal. Results reveal rather quick changes: Citations per year since original articles’ publication increase significantly, and the IF of the journals go up markedly. Frequencies of citing in German-language journals decrease, citing in English-language journals increase significantly after the Anglicization of former German-language psychology journals, and there is a general trend of increasing citations in other languages as well. Side effects of anglicizing former German-language psychology journals include the publication of shorter papers, their availability to a more international authorship, and a slight, but significant increase in multiple authorships.

scholarly journals The Impact of the Electric Field on Surface Condensation of Water Vapor: Insight from Molecular Dynamics Simulation

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 64 ◽  
Author(s):  
Qin Wang ◽  
Hui Xie ◽  
Zhiming Hu ◽  
Chao Liu
Keyword(s):  
Molecular Dynamics ◽  
Water Vapor ◽  
Electric Field ◽  
Intermolecular Forces ◽  
Dynamics Simulation ◽  
Water Molecules ◽  
Attraction Force ◽  
Condensation Rate ◽  
Shape Transformation ◽  
The Impact

In this study, molecular dynamics simulations were carried out to study the coupling effect of electric field strength and surface wettability on the condensation process of water vapor. Our results show that an electric field can rotate water molecules upward and restrict condensation. Formed clusters are stretched to become columns above the threshold strength of the field, causing the condensation rate to drop quickly. The enhancement of surface attraction force boosts the rearrangement of water molecules adjacent to the surface and exaggerates the threshold value for shape transformation. In addition, the contact area between clusters and the surface increases with increasing amounts of surface attraction force, which raises the condensation efficiency. Thus, the condensation rate of water vapor on a surface under an electric field is determined by competition between intermolecular forces from the electric field and the surface.

scholarly journals Exploring Factors Influencing Scenarios Evolution of Waste NIMBY Crisis: Analysis of Typical Cases in China

2021 ◽  
Vol 18 (4) ◽  
pp. 2006
Author(s):  
Ling He ◽  
Qing Yang ◽  
Xingxing Liu ◽  
Lingmei Fu ◽  
Jinmei Wang
Keyword(s):  
Network Theory ◽  
Development Process ◽  
Dynamic Bayesian Network ◽  
Impact Factors ◽  
Social Stability ◽  
Ground Theory ◽  
Evolution Path ◽  
Dynamic Scenario ◽  
The Impact

As the impact factors of the waste Not-In-My-Back Yard (NIMBY) crisis are complex, and the scenario evolution path of it is diverse. Once the crisis is not handled properly, it will bring adverse effects on the construction of waste NIMBY facilities, economic development and social stability. Consequently, based on ground theory, this paper takes the waste NIMBY crisis in China from 2006 to 2019 as typical cases, through coding analysis, scenario evolution factors of waste NIMBY crisis are established. Furtherly, three key scenarios were obtained, namely, external situation (E), situation state (S), emergency management (M), what is more, scenario evolution law of waste NIMBY crisis is revealed. Then, the dynamic Bayesian network theory is used to construct the dynamic scenario evolution network of waste NIMBY crisis. Finally, based on the above models, Xiantao waste NIMBY crisis is taken as a case study, and the dynamic process of scenario evolution network is visually displayed by using Netica. The simulation results show that the scenario evolution network of Xiantao waste NIMBY crisis is basically consistent with the actual incident development process, which confirms the effectiveness and feasibility of the model.

scholarly journals Do Agricultural Machinery Services Facilitate Land Transfer? Evidence from Rice Farmers in Sichuan Province, China

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 466
Author(s):  
Xi Yu ◽  
Xiyang Yin ◽  
Yuying Liu ◽  
Dongmei Li
Keyword(s):  
Negative Impact ◽  
Sichuan Province ◽  
Impact Factors ◽  
Farm Labor ◽  
Agricultural Machinery ◽  
Rice Farmers ◽  
Land Transfer ◽  
Land Rental ◽  
Rental Markets ◽  
The Impact

Agricultural machinery services play an increasingly important role in the land transfer market, especially in developing countries. Prior studies have explored the impact factors of machinery use on agricultural production and land transfer, respectively. However, little research has focused on the relationship between the adoption of agricultural machinery services and the land transfer of rice farmers. To bridge this gap, this study investigated the correlation between machinery services and land transfer, using unique survey data of 810 rice farmers collected from Sichuan province in China. Additionally, this study further explored the impact mechanism on land transfer of rural households with IV-Probit and IV-Tobit models. The empirical results show the following: (i) Agricultural machinery services have a significantly positive and robust effect on both the incidence and area of rice farmers’ land transfer-in, while the impact degree is different. Specifically, with other conditions remaining unchanged, and with a 1% increase in the proportion of machinery services, the average probability of land transfer-in of rice farmers increased by 2.4%, and the area of land transfer-in increased by 13.4 mu, on average. (ii) For control variables, head education, agricultural certificates and whether the majority of land, are in a flat area have positive impacts on land transfer-in behavior. Yet, age and off-farm labor have a negative impact on land transfer-in area. Moreover, our findings highlight the importance of agricultural machinery services in stimulating the development of rural land rental markets.

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