scholarly journals Fabrication of various micropatterns by maskless micro-electrochemical texturing

2019 ◽  
Vol 6 ◽  
pp. 6 ◽  
Author(s):  
Sandip Kunar ◽  
Bijoy Bhattacharyya
Keyword(s):  
Flow Rate ◽  
Cross Flow ◽  
Pulse Frequency ◽  
Electrochemical Micromachining ◽  
Duty Ratio ◽  
Machining Accuracy ◽  
Machining Time ◽  
Interelectrode Gap ◽  
Set Up ◽  
Cell Electrode

In this paper, an innovative and alternative concept of maskless micro-electrochemical texturing is exploited for the fabrication of simple and complex micropatterns. In this process, the tool is masked incorporated with the textured patterns and the workpiece has no mask. This research study concentrates on generation of simple micropattern, i.e. linear micropattern, and complex micropattern, i.e. cascade micropattern using maskless micro-electrochemical texturing method without repeated use of photolithography process. A single masked patterned tool with SU-8 2150 mask can produce many high-quality simple and complex micropatterns economically using this method. A well-planned experimental set-up consisting of electrochemical micromachining (EMM) cell, electrode fixtures, electrical connections and constricted vertical cross-flow electrolyte system has been designed and developed indigenously for carrying out the experiments. Influences of major influencing parameters, i.e. machining voltage, interelectrode gap, flow rate and machining time, are investigated on width overcut and machining depth of micropatterns. For higher machining accuracy, controlled depth and lower standard deviations, machining with lower machining time, lower voltage, lower interelectrode gap and higher flow rate is recommended. From the detailed experimental investigation, the best parametric combination are voltage of 8 V, duty ratio of 30%, pulse frequency of 15 kHz, electrolyte of NaCl (0.34 M) + NaNO3 (0.23 M), flow rate of 5.35 m3/h, interelectrode gap of 50 µm and machining time of 40 s.

Influence of electrolytes on surface texture characteristics generated by electrochemical micromachining

2018 ◽  
Vol 1 (2) ◽  
pp. 124-133 ◽  
Author(s):  
Sandip Kunar ◽  
S. Mahata ◽  
B. Bhattacharyya
Keyword(s):  
Flow Rate ◽  
Surface Engineering ◽  
Pulse Frequency ◽  
Electrochemical Micromachining ◽  
Duty Ratio ◽  
Machining Time ◽  
Novel Approach ◽  
Best Parameter ◽  
Work Samples ◽  
Set Up

Generation of microsurface texture is an important technology for surface engineering that can produce a significant improvement of engineering components in aspects to wear resistance, friction coefficient, load capacities, part lubrication, etc. This research proposes a novel approach of maskless electrochemical micromachining (EMM), which is anodic dissolution based on electrochemical reaction. One reused textured cathode tool with patterned SU-8 2150 mask can fabricate many work samples economically with less time. Maskless EMM set-up with developed EMM cell and vertical crossflow electrolyte supply system is used to generate micro circular patterns on stainless steel (SUS 304) using three different types of electrolytes such as NaCl, NaNO3 and NaCl + NaNO3. The influences of major process parameters such as interelectrode gap (IEG), flow rate, machining time and electrolyte concentration on mean radial overcut and mean machining depth have been investigated using these electrolytes. Out of these three electrolytes, only NaCl + NaNO3 of 20 g l−1 is selected as the best electrolyte with other best parameter settings such as applied voltage of 12 V, duty ratio of 30%, pulse frequency of 5 kHz, flow rate of 3.12 m3 hr−1, IEG of 50 µm and machining time of 3 minutes for generating good textured characteristics with overcut of 27.581 µm and depth of 15.1 µm. Analyses have also been done to investigate the textured characteristics using these electrolytes for acquiring the best parametric combination with suitable electrolyte.

scholarly journals Fabrication of array of micro circular impressions using different electrolytes by maskless electrochemical micromachining

2020 ◽  
Vol 7 ◽  
pp. 15 ◽  
Author(s):  
S. Kunar ◽  
E. Rajkeerthi ◽  
K. Mandal ◽  
B. Bhattacharyya
Keyword(s):  
Experimental Investigation ◽  
Cross Flow ◽  
Surface Characteristics ◽  
Pulse Frequency ◽  
Electrochemical Micromachining ◽  
Duty Ratio ◽  
Mixed Electrolyte ◽  
Radial Overcut ◽  
Cell Electrode ◽  
Electrical Connections

Maskless electrochemical micromachining (EMM) is a prominent technique for producing the array of micro circular impressions. A method for producing the array of micro circular impressions on stainless steel workpiece applying maskless electrochemical micromachining process is presented. The experimental setup consists of maskless EMM cell, electrode holding devices, electrical connections of electrodes and constricted vertical cross flow electrolyte system to carry out the experimental investigation. One non-conductive masked patterned tool can produce more than twenty six textured samples with high quality. A mathematical model is developed to estimate theoretically the radial overcut and machining depth of the generated array of micro circular impressions by this process and corroborate the experimental results. This study provides an elementary perceptive about maskless EMM process based on the effects of EMM process variables i.e. pulse frequency and duty ratio on surface characteristics including overcut and machining depth for NaCl, NaNO3 and NaNO3 + NaCl electrolytes. From the experimental investigation, it is observed that the combined effect of lower duty ratio and higher frequency generates the best array of micro circular impressions using the mixed electrolyte of NaNO3 + NaCl with mean radial overcut of 23.31 µm and mean machining depth of 14.1 µm.

FABRICATIONS OF MICRO TOOLS AND MICRO PATTERNS BY ELECTROCHEMICAL MICROMACHINING AND SOME INVESTIGATION INTO OVERPOTENTIAL

2013 ◽  
Vol 12 (02) ◽  
pp. 85-106 ◽  
Author(s):  
V. K. JAIN ◽  
A. S. CHAUHAN ◽  
ANURAG THAKUR ◽  
AJAY SIDPARA
Keyword(s):  
Duty Cycle ◽  
Electrolyte Concentration ◽  
Machining Process ◽  
Electrochemical Micromachining ◽  
Duty Ratio ◽  
Machining Time ◽  
Interelectrode Gap ◽  
Advanced Machining ◽  
Micro Tools ◽  
Micro Patterns

Electrochemical micromachining (ECMM) is a well-known advanced machining process for fabrication of micro components such as tools, nozzles, mixers, etc. on electrically conductive workpieces. In the present work, experiments are conducted for fabrication of micro tools and micro patterns on the in-house developed and fabricated electrochemical micromachining setup. Effect of various process parameters such as voltage, interelectrode gap, machining time, duty cycle, and electrolyte concentration are studied on micro tools and over potential (in case of fabrication of micro patterns). It is observed that the average change in diameter of the micro tool after the ECMM process increases almost linearly with increase in voltage and time, and increases quadratically with increase in pulse duty ratio and electrolyte concentration. Overpotential increases with increase in applied voltage, interelectrode gap, and duty cycle. Further, overpotential initially decreases quadratically with increase in electrolyte concentration and then increases.

Process Parameter Optimization and Experimental Study of Micro-Holes in Electrochemical Micromachining Using Pulse Current

2010 ◽  
Vol 135 ◽  
pp. 293-297 ◽  
Author(s):  
Zhi Yong Li ◽  
Zong Wei Niu
Keyword(s):  
Electrolyte Concentration ◽  
Pulse Frequency ◽  
Electrochemical Process ◽  
Electrochemical Micromachining ◽  
Machining Accuracy ◽  
Ultrasonic Frequency ◽  
Voltage Range ◽  
Micro Holes ◽  
Set Up ◽  
Pulse On Time

Electrochemical micro-machining (EMM) has become one of the main machining methods for production of miniaturized parts and components. Utilizing a developed EMM set-up, sets of experiments have been carried out to investigate the influences of some of the predominant electrochemical process parameters such as pulse frequency, feed rate of tool, machining voltage and ultrasonic frequency on the machining accuracy of micro-holes. According to the present investigation, the most effective zone of pulse on time and ultrasonic frequency can be considered as 15-50μs and 26KHZ, respectively, which can gives a desirable machining accuracy for micro-holes. A machining voltage range of 6-10V can be commended to obtain high machining accuracy. From the micrographs of the machined micro-holes, it may be observed that a lower value of electrolyte concentration with moderate machining voltage and moderate value of pulse on time will produce more accurate shape of micro-holes.

Electrochemical micromachining of large-area micro-dimple arrays with high machining accuracy

2016 ◽  
Vol 232 (11) ◽  
pp. 1918-1927 ◽  
Author(s):  
Zhibao Hou ◽  
Ningsong Qu ◽  
Xiaolei Chen
Keyword(s):  
Duty Cycle ◽  
Applied Voltage ◽  
Electrical Discharge Machining ◽  
Electrochemical Micromachining ◽  
Machining Accuracy ◽  
Large Area ◽  
Machining Time ◽  
Pillar Arrays ◽  
Micro Dimples ◽  
Micro Dimple

Surface textures, especially micro-dimple arrays, can significantly improve the friction performance of engineering parts. Through-mask electrochemical micromachining is an effective method for generating micro-dimple arrays. In this article, a new method is introduced to fabricate a large-area polydimethylsiloxane mask containing micro through-holes. Using this technique, a stainless steel mould with micro-pillar arrays is generated by wire electrical discharge machining. A combination of pressure and weight of electrolyte is then proposed to keep the polydimethylsiloxane mask closely attached to the workpiece, which helps to achieve high machining accuracy. The effects of applied voltage, effective machining time and pulse duty cycle on the micro-dimples are investigated. The profiles of the micro-dimples are not sensitive to applied voltage, but pulse duty cycle is a significant factor influencing the depth of the micro-dimples. Micro-dimples of width 95 µm, depth 19 µm and a machining area of diameter 40 mm are successfully generated using a polydimethylsiloxane mask, and the standard deviations of the micro-dimple width and depth are only 0.84 and 0.23 µm, respectively. The present experiments verify that it is feasible to obtain large-area micro-dimple arrays with high machining accuracy using this technique.

scholarly journals Investigation on the Electrochemical Micromachining of Micro Through-Hole by Using Micro Helical Electrode

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 118 ◽  
Author(s):  
Baohui Liu ◽  
Hang Zou ◽  
Haixuan Luo ◽  
Xiaoming Yue
Keyword(s):  
Process Parameters ◽  
High Speed ◽  
Pulse Frequency ◽  
Machining Process ◽  
Electrochemical Micromachining ◽  
Good Effect ◽  
Machining Accuracy ◽  
High Speed Rotation ◽  
Helical Electrode ◽  
Through Hole

The instability of machining process caused by the difficulty of the electrolyte refresh in electrochemical micromachining (EMM) of micro through-hole has been an unsolved problem. Thus, this paper investigates the electrochemical micromachining of micro through-hole by using a micro helical electrode combining with the jetting electrolyte. With the help of high-speed rotation of micro helical electrode and its spiral shape, the internal electrolyte can be stirred while the external jetting electrolyte can flow into the hole along the spiral groove to refresh the electrolyte effectively, thereby, improving the machining stability of EMM. Firstly, the influence of the process parameters on the fabrication of micro through-hole in the EMM by using micro helical electrode without non-conductive mask is investigated. Based on the optimization of the process parameters, a micro through-hole with an inlet dimension of 121.6 μm and an outlet dimension of 114.9 μm is obtained successfully. Furthermore, this paper also tries to use the micro helical electrode coated with the non-conductive mask to decrease the bad influence of the stray corrosion attack. It is found that the non-conductive mask coated on the surface of micro helical electrode can improve the machining accuracy significantly under the condition of low pulse frequency (≤1 KHz). However, its good effect on preventing the stray corrosion decreases along with the increase of the pulse frequency.

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.

Parametric Investigation Into the Fabrication of Disk Microelectrodes by Electrochemical Micromachining

2013 ◽  
Vol 1 (4) ◽  
Author(s):  
Vijaysing Rathod ◽  
B. Doloi ◽  
B. Bhattacharyya
Keyword(s):  
Surface Quality ◽  
Process Parameters ◽  
Removal Rate ◽  
Electrochemical Micromachining ◽  
Duty Ratio ◽  
Machining Accuracy ◽  
Surface Residual Stress ◽  
Taper Angle ◽  
Electro Discharge Machining ◽  
Disk Height

In electrochemical micromachining (EMM) of microfeatures using straight cylindrical microtools, sidewalls of the structure tapers as depth increases. Disk microtool electrodes are used to minimize the taper formation during the machining of microfeatures. At present disk microtool electrodes are fabricated by wire electrical discharge grinding, reverse electro discharge machining (EDM), and microwire electro discharge machining method, which needs separate EDM machine as well as fabricated microtools suffer from thermal defects like microcracks on surface, residual stress, deformation, and needs careful handling. To overcome these limitations, new method is proposed to fabricate disk microtool electrode by EMM. Also the influences of EMM process parameters like applied voltage, pulse frequency, duty ratio, electrolyte concentration on shank diameter, material removal rate, and surface quality are investigated. Disk microtool electrode of disk height 70 μm, disk diameter 175 μm, shank diameter 93 μm, and shank height 815 μm have been fabricated from tungsten microrod of 300 μm diameter by proposed method and used to machine microfeatures like cylindrical hole with reduced taper angle, reverse taper hole, taper free microgroove, and 3D microstructure with plane surfaces on stainless steel by EMM. Effects of disk height on machining accuracy during generation of microhole, in the form of taper angle are also presented in the paper. Proposed method of developing disk electrode by EMM will be very useful for fabricating disk microtool electrodes with different disk diameters, disk heights, shank diameter, and shank height with desired surface quality by controlling various process parameters. Disk microtools with lower disk heights are more effective to generate microfeatures with minimum taper.

On the Influence of the Slot Orifice in Diesel Common Rail Nozzle

2018 ◽  
Vol 11 (1) ◽  
pp. 55-69 ◽  
Author(s):  
Giancarlo Chiatti ◽  
Ornella Chiavola ◽  
Fulvio Palmieri ◽  
Roberto Pompei
Keyword(s):  
Cross Section ◽  
Flow Rate ◽  
Experimental Analysis ◽  
Common Rail ◽  
Spray Angle ◽  
The Novel ◽  
Hydraulic Behavior ◽  
Reference Information ◽  
Light Duty ◽  
Set Up

Background:The paper deals with a diesel common rail nozzle in which a novel orifice layout is implemented.Objective:Its influence on the nozzle mechanical-hydraulic behavior and on the spray shape transient development is experimentally investigated.Methods:In the research, a solenoid injector for light duty diesel engines is equipped with the novel nozzle prototype and tested. The prototype layout is described, pointing out the features of the nozzle orifices, in which a Slot cross-section is adopted; the investigation is accomplished extending the hydraulic tests and the spray visualizations to a reference nozzle with standard holes. The influence of the hole layout on the mechanical-hydraulic behavior of the nozzle is assessed by experimental analysis based on the rate of injection measurement, in comparison with the reference nozzle. Once the hydraulic behavior of the novel nozzle has been characterized in terms of mass flow rate, the slot influence on the spray shape is assessed analyzing the macroscopic features such as the penetration distance and the spray angle, in non evaporative conditions. The study is carried out under transient injection conditions, for different injection pressures, up to 1400 bar.Results:The results on spray characteristics also provide reference information to set up spray models suited to take the Slot orifice into account.

scholarly journals Using uniform design and regression methodology of turning parameters study of nickel alloy

2021 ◽  
Author(s):  
Shao-Hsien Chen ◽  
Chih-Hung Hsu
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Nickel Alloy ◽  
Design Methodology ◽  
Cutting Tool ◽  
Uniform Design ◽  
Machining Time ◽  
Variable Parameters ◽  
Cutting Test ◽  
Set Up

AbstractThe nickel alloy has good mechanical strength and corrosion resistance at high temperature; it is extensively used in aerospace and biomedical and energy industries, as well as alloy designs of different chemical compositions to achieve different mechanical properties. However, for high mechanical strength, low thermal conductivity, and surface hardening property, the nickel alloy has worse cutting tool life and machining efficiency than general materials. Therefore, how to select the optimum machining parameters will influence the workpiece quality, cost, and machining time. This research will be using a new experimental design methodology to the cutting parameter planning for nickel-based alloy cutting test, and used the uniform design methodology to cutting test to reduce the number of experiments. Three independent variable parameters are set up, including cutting speed, feed rate, and cutting depth, and four dependent variable parameters are set up, including cutting tool wear, surface roughness, machining time, and cutting force. A nickel alloy turning parameter model is built by using regression analysis to further predict the I/O relationship among various combinations of variables. The errors between actual values and prediction values are validated. When the cutting tool wear (VB) is 2.72~6.18%, the surface roughness (Ra) is 4.10~7.72%, the machining time (T) is 3.75~8.82%, and the cutting force (N) is 1.54~7.42%; the errors of various dependent variables are approximately less than 10%, so a high precision estimation model is obtained through a few experiments of uniform design method.

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