scholarly journals Effects of a Magnetic Field on the Machining Accuracy for the Electrochemical Drilling of Micro Holes

2020 ◽  
pp. 1148-1159
Author(s):  
Changfu Zhang ◽  
Keyword(s):  
Magnetic Field ◽  
Machining Accuracy ◽  
Electrochemical Drilling ◽  
Micro Holes

scholarly journals Fabrication of Taper Free Micro-Holes Utilizing a Combined Rotating Helical Electrode and Short Voltage Pulse by ECM

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 28 ◽  
Author(s):  
Yong Liu ◽  
Minghong Li ◽  
Jingran Niu ◽  
Shizhou Lu ◽  
Yong Jiang
Keyword(s):  
Voltage Pulse ◽  
High Speed ◽  
Manufacturing Industry ◽  
Difficult Problem ◽  
Machining Accuracy ◽  
Gap Flow ◽  
Electrochemical Drilling ◽  
Micro Holes ◽  
Micro Hole ◽  
Helical Electrode

Fabrication of the injection nozzle micro-hole on the aero engine is a difficult problem in today’s manufacturing industry. In addition to the size requirements, the nozzle micro-hole also requires no burr, no taper and no heat-affected zone. To solve the above problem, an ultra-short voltage pulse and a high-speed rotating helical electrode were used in electrochemical drilling (ECD) process. Firstly, a theoretical model of ECD with ultra-short voltage pulse was established to investigate the effects of many predominant parameters on machining accuracy, and the effect of rotating helical electrode on the gap flow field was analyzed. Secondly, sets of experiments were carried out to investigate the effects of many key parameters on machining accuracy and efficiency. Finally, the optimized parameters were applied to machine micro holes on 500 μm thickness of GH4169 plate, and micro-holes with the diameter of 186 μm with no taper were machined at the feed rate of 1.2 μm/s. It is proved that the proposed ECD process for fabricating micro-holes with no taper has a huge potential and broad application prospects.

Fabrication of High-Aspect Ratio Micro Holes on Hard Brittle Materials -Study on Electrorheological Fluid-Assisted Micro Ultrasonic Machining-

2008 ◽  
Vol 389-390 ◽  
pp. 264-270 ◽  
Author(s):  
T. Tateishi ◽  
Nobuhito Yoshihara ◽  
Ji Wang Yan ◽  
Tsunemoto Kuriyagawa
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Brittle Materials ◽  
Electrorheological Fluid ◽  
Machining Accuracy ◽  
Machining Efficiency ◽  
Ultrasonic Machining ◽  
Auxiliary Electrode ◽  
Abrasive Grains ◽  
Micro Holes

Ultrasonic machining (USM) is an effective method for machining of hard brittle materials. In this process, the slurry is supplied to the gap between the workpiece and the ultrasonic vibrating tool, and the materials are removed by the impacts of the abrasive grains that are pressurized by an ultrasonic vibrating tool. The purpose of this research is to achieve precise and efficient microfabrication on hard brittle materials by USM. However, in the case of microfabrication, chipping which is generally observed around the edges of machined micro holes and grooves, deteriorates the machining accuracy. In addition, there is another problem in that the machining efficiency decreases with the progress of the machining. Electrorheological fluid-assisted USM has been proposed as a countermeasure to these problems. In the present study, the problems and countermeasures associated with the machining of high-aspect ratio micro holes in hard brittle materials by electrorheological fluid-assisted USM are investigated. By positioning an auxiliary electrode under the workpiece, it becomes possible to keep the electric field high even when the machining depth becomes large. As a result, high-precision and high-aspect ratio micro holes can be machined on hard brittle materials.

Micro-Hole Machined by Electrochemical Discharge Machining (ECDM) with High Speed Rotating Cathode

2011 ◽  
Vol 295-297 ◽  
pp. 1794-1799 ◽  
Author(s):  
Shao Fu Huang ◽  
Di Zhu ◽  
Yong Bin Zeng ◽  
Wei Wang ◽  
Yong Liu
Keyword(s):  
High Speed ◽  
Electrochemical Machining ◽  
304 Stainless Steel ◽  
Machining Accuracy ◽  
Micro Machining ◽  
Rotating Speed ◽  
Electrochemical Discharge Machining ◽  
Electrochemical Discharge ◽  
Micro Holes ◽  
Micro Hole

Electrochemical discharge machining (ECDM), based on electrochemical machining (ECM) and electrodischarge machining (EDM), is an unconventional micro-machining technology. In this paper, with the use of water, the process of micro hole on ANSI 304 stainless steel machined by micro-ECDM with high speed rotating cathode is studied. The effects of machining conditions such as the cathode rotating speed and cathode diameter on the surface quality and accuracy of the shape are investigated. The results indicate that a relatively higher electrode rotating speed can improve the machining accuracy of the micro-holes and reduce the electrodes wear.

Development and Implementation of a Method for Chatter Control in Turning Applying Magnet from below the Tool

2013 ◽  
Vol 394 ◽  
pp. 205-210
Author(s):  
A.K.M. Nurul Amin ◽  
Fawaz Mohsen Abdullah ◽  
Ummu Atiqah Khairiyah B. Mohammad ◽  
Muammer Din Arif
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Metal Removal ◽  
Removal Rate ◽  
Research Work ◽  
Vibration Monitoring ◽  
Machining Accuracy ◽  
Machining Processes ◽  
Resonant Amplitude ◽  
Coated Carbide

Chatter is a self-excited and violent form of vibration which is almost unavoidable in all machining processes. It affects surface roughness, machining accuracy, cutting tool and machine tool life, metal removal rate; and consequently operation cost. This research work focuses on investigation of the influence of the cutting parameters on chatter and implementation of a method based on application of permanent magnet for controlling chatter during turning of stainless steel AISI 304 using coated carbide tool. For this purpose, a powerful permanent bar magnet (of strength 1250-1350 Gauss) was placed inside a specially developed fixture mounted on the lathe machine carriage, to apply magnetic field to the base of the tool holder in the Z direction. The effectiveness of the application of the magnet on chatter suppression was measured in terms of reduction of amplitude of chatter compared to conventional turning. To achieve this, a small central composite design (CCD) of the Response Surface Methodology (RSM) with five levels and an alpha value of 1.4142, was used in the design of the experiments (DoE). Design-Expert 6.0 software was utilized in the model development process. Vibration monitoring was done using an online vibration monitoring system. FFT analysis of the recorded vibration signals was conducted using DASYLab software to evaluate the peak chatter amplitudes and their corresponding excited frequencies. The acceleration amplitude was found to be reduced by a maximum of 73.43% and an average of 31.58% due to the effect of damping on the resonant amplitude offered by the magnetic field created by the permanent magnet.

Chatter Suppression with Magnetic Damping in Turning of Stainless Steel AISI 304

2013 ◽  
Vol 393 ◽  
pp. 183-188 ◽  
Author(s):  
Ummu Atiqah Khairiyah B. Mohammad ◽  
A.K.M.N. Amin ◽  
Muhd Amir Hafiz Bin Ahamad Mahrodi ◽  
Muammer D. Arif
Keyword(s):  
Magnetic Field ◽  
Stainless Steel ◽  
Permanent Magnet ◽  
Surface Finish ◽  
Machining Accuracy ◽  
Aisi 304 ◽  
Tool Holder ◽  
Chatter Suppression ◽  
Steel Aisi ◽  
Stainless Steel Aisi

Chatter is almost an unavoidable phenomenon during machining, normally accompanied by a characteristic sharp and monotonous noise. Apart from noise pollution in the industry, chatter leaves a bad surface finish on the part and negatively influences dimensional tolerances, reduced productivity, excessive tool wear and damaged machine-tool components. Therefore, chatter avoidance is utmost importance. However, a deeper investigation into chatter formation reveals that chatter appears during metal cutting process as a result of resonance caused by interaction of the prominent natural frequencies of the system with the frequency of chip serration. This paper presents an innovative approach to chatter suppression during turning of stainless steel AISI 304 applying permanent magnet from the bottom of the tool holder to increase the damping coefficient of the tool holder, since it has been identified that the tool holder is the main vibrating component during turning. A special fixture was designed, fabricated and mounted on the carriage of a conventional turning machine Harrison M390 for holding a permanent magnet bar. The variable cutting parameters were - cutting speed, feed rate and depth of cut at constant tool overhang of 120 mm. The experiments were designed based small Central Composite Design (small CCD) based on the Response Surface Methodology (RSM) approach using DESIGN EXPERT (DOE) software. The experiments were performed under two different conditions, the first under normal conditions, while the other was under the application of magnetic field from permanent magnet located side direction of the tool holder. The experiments focused on monitoring the vibration signals using a vibration data acquisition system during turning operation. Analysis of the recorded signals in the FFT domain indicated significant reduction of chatter when a magnetic field is applied. It is apparent that a reduction of chatter amplitude will result in improved surface finish, tool life, machining accuracy, productivity, as well as reduction of operation.

The mechanism of improving machining accuracy of ECM by magnetic field

2004 ◽  
Vol 149 (1-3) ◽  
pp. 409-413 ◽  
Author(s):  
Zhijian Fan ◽  
Tiancheng Wang ◽  
Ling Zhong
Keyword(s):  
Magnetic Field ◽  
Machining Accuracy

Research on the Boring Chatter Suppression Based on MR Fluid

2006 ◽  
Vol 532-533 ◽  
pp. 365-368
Author(s):  
Tian Rong Kong ◽  
Zhe He Yao ◽  
Zi Chen Chen
Keyword(s):  
Magnetic Field ◽  
Experimental System ◽  
Machining Accuracy ◽  
Mr Fluid ◽  
Boring Bar ◽  
Chatter Suppression ◽  
Excitation Coil ◽  
Precision Hole ◽  
Stiffness And Damping ◽  
Working Efficiency

Chatter during boring process is one of the main adverse factors influenced on the machining accuracy of precision hole, surface quality and working efficiency. In order to suppress chatter, an innovative controlling means of MR-intelligent-boring-bar with self-chatter-suppression is proposed, which is composed of MR fluid, shell structure, excitation coil and boring bar. The MR fluid’s mechanical characteristic can be adjusted by changing the intensity of magnetic field, thus the system stiffness and damping will be modified, and then the boring chatter can be suppressed. Otherwise, the dynamic model of MR-intelligent-boring-bar with self-chatter-suppression is built. Lastly, the experimental system of MR-intelligent-boring-bar is established, and the experiments of chatter suppression during boring process are performed. The results of experiments show that the new means of chatter suppression is effective.

Electrochemical Micro Drilling of Stainless Steel with Tool Electrode Jump Motion

2009 ◽  
Vol 626-627 ◽  
pp. 333-338 ◽  
Author(s):  
Zhuang Liu ◽  
Z.J. Qiu ◽  
C. Heng ◽  
Ning Song Qu
Keyword(s):  
Stainless Steel ◽  
Linear Motor ◽  
Machining Accuracy ◽  
Tool Electrode ◽  
Machining Time ◽  
High Acceleration ◽  
Micro Holes ◽  
Micro Drilling ◽  
Time Lead ◽  
Accelerating Motion

ECM micro drilling with tool electrode jump motion in cycles is introduced in this work. A linear motor is employed to carry tool to jump with high acceleration in cycles. Due to the high accelerating motion of tool electrode, the electrolyte within machining gap is able to be refreshed. The Z-axis feeding motor, linear motor and DC supplier are coupled in the experimental setup and a series of micro-holes are drilled on stainless steel (1Cr18Ni9Ti) plate with thickness of 0.5mm to investigate the presented process. Experimental results shows, cycle jump motion of tool electrode, higher jump acceleration, longer jump height and shorter cycle machining time lead to better machining accuracy.

Frequency Pulse Period and Duty Factor Effects on Electrochemical Micromachining (EMM)

2011 ◽  
Vol 264-265 ◽  
pp. 1334-1339 ◽  
Author(s):  
M. Malapati ◽  
A. Sarkar ◽  
B. Bhattacharyya
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Duty Factor ◽  
Electrochemical Micromachining ◽  
Machining Accuracy ◽  
Pulse Period ◽  
Sem Micrographs ◽  
Micro Holes ◽  
Frequency Pulse

Electrochemical micromachining (EMM) appears to be promising as a future micro machining technique since in many areas of applications; it offers several advantages including electronic, biomedical and MEMS/NEMS applications. Present paper will highlight the influence of various EMM process parameters i.e. machining voltage, electrolyte concentration, frequency pulse period and duty factor on machining performance criteria e.g. material removal rate and machining accuracy to meet the micromachining requirements. Some of the experiments had been carried out on copper to investigate the most effective zone, which gives high machining accuracy with appreciable amount of material removal rate. Attempt has also been made to study and compare the surface condition of the machined micro-holes through SEM micrographs. From the analysis of test results and SEM micrographs it can be observed that optimum value of frequency pulse period is about 200 μsec and duty factor is about 20% which will produce accurate micro-holes with highest possible amount of material removal.

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