scholarly journals Performance Improvement of High-speed Edm and Ecm Combined Process by Using a Helical Tube Electrode With Matched Internal and External Flushing

2021 ◽  
Author(s):  
Lei Ji ◽  
Yan Zhang ◽  
Guoqian Wang ◽  
Jie Zhang ◽  
Wentao Yang
Keyword(s):  
Surface Quality ◽  
Electrical Discharge ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Electrochemical Machining ◽  
Machining Parameters ◽  
Tube Electrode ◽  
Helical Tube ◽  
Narrow Gaps ◽  
Helical Electrode

Abstract Micro-hole fabrication at a high speed and accuracy of machining while maintaining high surface quality is challenging. A core difficulty is the removal of the products of machining from extremely narrow gaps. To solve this problem, this study proposes an approach that combines high-speed electrical discharge machining (EDM) with electrochemical machining (ECM) by using a helical tube electrode with matched internal and external flushing. During high-speed electrical discharge drilling, matching the internal flushing with the clockwise rotation of the helical electrode can help remove debris from the bottom of the blind hole. During ECM, matching the external flushing with the anticlockwise rotation of the helical electrode can improve the flow of electrolyte in the gap. First, the flow field was simulated to show that matching the internal and external flushing of the helical electrode can enhance the flow of the medium and reduce particle concentration in extremely narrow gaps. Second, a series of experiments were conducted to verify that the taper of the hole and the surface quality of its wall can be improved by using the helical tube electrode. Finally, an experiment was carried out to optimize the machining parameters, and yielded a minimum taper of 0.008 at a speed of rotation of 460 rpm, and pressures of internal and external flushing of 9 MPa and 4 MPa, respectively.

scholarly journals Geometric Accuracy Improvement by Using Electrochemical Reaming with a Helical Tube Electrode as Post-Processing for EDM

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3564
Author(s):  
Yan Zhang ◽  
Chen Wang ◽  
Yu Wang ◽  
Qin Ni ◽  
Lei Ji
Keyword(s):  
Flow Field ◽  
Surface Quality ◽  
Electrical Discharge Machining ◽  
Cylindrical Tube ◽  
Helical Structure ◽  
Machining Accuracy ◽  
Machining Parameters ◽  
Post Processing ◽  
Tube Electrode ◽  
Helical Tube

Electrochemical reaming using a helical tube electrode together with lateral flushing is proposed as post-processing to improve the machining accuracy and surface quality of holes produced by electrical discharge machining (EDM). The velocity distributions of flushing in the machining gap for a cylindrical tube electrode and for a helical tube electrode were compared using flow field simulations. The role of the helical structure in promoting removal of machining products was illustrated by the results of the flow field simulations for different lateral flushing pressures. The performance of electrochemical reaming as post-processing in improving machining accuracy and surface quality was verified by comparative experiments examining the exit circularity error, taper, and surface morphology of machined holes. Finally, an optimum combination of machining parameters was obtained through a process parameter optimization experiment.

Removal of Defective Layer after Electrical Discharge Machining

2019 ◽  
Vol 973 ◽  
pp. 157-160
Author(s):  
Stanislav A. Mozgov ◽  
Yuriy A. Morgunov ◽  
Boris P. Saushkin
Keyword(s):  
Electrical Discharge ◽  
Metal Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Electrochemical Machining ◽  
Work Piece ◽  
Machining Parameters ◽  
Electrode Gap ◽  
Machining Time ◽  
Defective Layer

This study investigates the possibility of electrochemical removal of the defective layer formed on the surface of the product after its electrical discharge machining. A set of experiments was conducted in different electrolytes based on aqueous and aqueous-organic solvents. The experiments were to trace the influence of such settings of electrochemical machining as current density, electrolyte pumping speed, electrolyte temperature, and an electrode gap upon both the dynamics of metal removal and surface quality. Morphology of the obtained surface was examined by an Olympus BX-51Microscope. The dynamics of removing material (stock) from the work piece was inspected. Appropriate adjustments were made to the machining parameters during the machining of 65G steels, and a preferred composition was selected for the working medium. A sufficient design for production tools was proposed. Pitting corrosion was discovered on the surface of the samples in all studied modes of electrolysis. It was observed that switching from aqueous electrolyte to aqueous-organic electrolyte gave lower material removal rate and longer machining time accordingly. At the same time, a reduction in surface roughness was visualized, together with smaller pits and lower density of their distribution. The obtained results may be applied in operation design for electrochemical machining of steels with relatively high carbon contents.

scholarly journals Study on Ultrasonic Assisted Electrochemical Drill-Grinding of Superalloy

Chemosensors ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 62
Author(s):  
Huanghai Kong ◽  
Yong Liu ◽  
Xiangming Zhu ◽  
Tengfei Peng
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
High Speed ◽  
Electrochemical Machining ◽  
Machining Parameters ◽  
Mechanical Grinding ◽  
High Quality ◽  
Passive Behavior ◽  
Ultrasonic Assisted ◽  
Small Holes

Electrochemical grinding (ECG) technique composed of electrochemical machining (ECM) and mechanical grinding is a proper method for machining of difficult-to-cut alloys. This paper presents a new ultrasonic assisted electrochemical drill-grinding (UAECDG) technique which combines electrochemical drilling, mechanical grinding, and ultrasonic vibration to fabricating high-quality small holes on superalloy. By applying ultrasonic vibration to high-speed rotating electrode in ECG, machining stability, efficiency, and surface quality can be obviously improved. Firstly, the electrochemical passive behavior of superalloy is studied, the mathematical model and simulation of gap electric field are established. Then, several experiments are conducted to investigate the influence of applied voltage, feed rate and ultrasonic amplitude on the machining quality. The balance of material removal between electrochemical reaction and mechanical grinding is achieved by optimizing the machining parameters. It reveals that the surface quality as well as machining stability and efficiency can be significantly improved by applying rotating ultrasonic vibration to the ECG process. Finally, several small holes of high quality have been machined successfully along with surface roughness of hole sidewall decreases from Ra 0.99 μm to Ra 0.14 μm by UAECDG.

Experimental Studies on Dry WEDM in Improving Surface Quality

2009 ◽  
Vol 626-627 ◽  
pp. 327-332 ◽  
Author(s):  
Tong Wang ◽  
Yu Mei Lu ◽  
Q. Chen ◽  
S.H. Zhou
Keyword(s):  
Surface Quality ◽  
Electrical Discharge ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Experimental Studies ◽  
Pulse Interval ◽  
Wire Length ◽  
Dry Wedm ◽  
Dry And Wet Conditions

This study investigates the dry wire electrical discharge machining (WEDM) in multiple cut. To improve surface quality with high-speed WEDM (HS-WEDM), a new procedure as Gas-liquid Combined Multiple Cut (roughing is processed in dielectric liquid, and semi-finishing is in liquid or gas, while the finishing is in gas) is presented. Effects of pulse duration, pulse interval, peak current, offset, wire winding speed and wire length on roughness, straightness and removal rate had been studied in dry and wet conditions. Experiment results show that multiple cut with dry WEDM in semi-finishing and finishing can improve surface roughness significantly.

Investigating the Effects of Powder Mixed Electrical Discharge Machining on the Surface Quality of γ–TiAl Intermetallic

2012 ◽  
Vol 488-489 ◽  
pp. 396-401 ◽  
Author(s):  
B. Jabbaripour ◽  
M.H. Sadeghi ◽  
Mohammad Reza Shabgard ◽  
S. Shajari ◽  
H. Hassanpour
Keyword(s):  
Silicon Carbide ◽  
Surface Quality ◽  
Aluminum Powder ◽  
Automotive Industry ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Machining Parameters ◽  
Working Temperature ◽  
Corrosion Creep

Due to outstanding properties of γ–TiAl intermetallic such as high resistance against fatigue, oxidation, corrosion, creep, dynamic vibration, high working temperature and also its application in aerospace, automotive industry and turbojet engines; in this paper, powder mixed electrical discharge machining (PMEDM) of γ–TiAl intermetallic by means of different additive powders including aluminum (Al), graphite (Gr), silicon carbide (SiC), chrome (Cr) and iron (Fe) is investigated to compare the output characteristic of surface quality and roughness. The results indicate that aluminum powder produces the best surface finish, followed by silicon carbide, graphite, chrome and iron respectively. The experimental results show that in the determined settings of input machining parameters, aluminum powder can improve the surface roughness of TiAl sample about 32%.

Study on Dry WEDMed Surface Quality of Mould Steel

2008 ◽  
Vol 375-376 ◽  
pp. 416-420 ◽  
Author(s):  
Tong Wang ◽  
Xin Fu Zhang ◽  
Xue Fang Zhao
Keyword(s):  
Surface Quality ◽  
Electrical Discharge ◽  
Material Removal ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Finish Cut ◽  
Straightness Error ◽  
Discharge Gap

This paper studies the surface quality of tool steel with high-speed wire electrical discharge machining (WEDM) method, which is conducted in gas to improve the accuracy of finish cut, and compares the surface quality in atmosphere and in emulsion dielectric. Experiment results showed that WEDM in atmosphere offers advantages such as better straightness and higher material removal rate. With the growth of wire winding speed, the removal rate and straightness error will increase significantly either in atmosphere or in liquid. Along with the feed increasing, the discharge gap lengthes decrease successively under the both media conditions, and the straightness is obviously improved in atmosphere. Regardless of the use of atmosphere or emulsion, an optimum feed will exist, which makes the roughness the lowest and the removal rate the highest.

Precise-Micro PECM System and its Applications Combining Synchronizing Ultrasonical Vibration

2011 ◽  
Vol 295-297 ◽  
pp. 834-839 ◽  
Author(s):  
Yong Wei Zhu ◽  
Xing Lei Miao ◽  
Chao Feng Zhang
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Electrical Discharge Machining ◽  
New Technology ◽  
Electrochemical Machining ◽  
Electrical Circuit ◽  
Machining Accuracy ◽  
Machining Parameters ◽  
Micro Machining ◽  
High Productivity

The micro-PECM (Pulse Electrochemical Machining) combining synchronous ultrasonic vibration is proposed as a new technology for to solve the difficulty machining problems of conductive hard and tough materials. The feasibility of micro-PECM combining synchronous ultrasonic vibration is studied. The synchronous way is analyzed; the synchronous electrical circuit is designed and made. The synchronous electrochemical micro-machining system combining ultrasonical vibration are built and improved，which machining parameters can be adjusted in a wide ranges, and the synchronous target of the ultrasonical vibration with the voltage of micro-PECM can be realized. The micro-machining electrodes are manufactured in different sections and sizes by combined electrical discharge machining. The mechanism tests of micro-PECM are carried, which kentaniums （YBD151、YG8）and stainless steel are machined and the results are analyzed and discussed. Contrast with the single micro-USM, the micro-PECM combining ultrasonic vibration has high productivity, good machining accuracy and surface quality; furthermore, its cathode wastage is low. The micro-PECM combining synchronous ultrasonic vibration has the best machining precision and surface quality.

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