Gas-Liquid Combined Multiple Cut in High-Speed WEDM

2010 ◽  
Vol 97-101 ◽  
pp. 4168-4171
Author(s):  
Tong Wang ◽  
Yu Mei Lu ◽  
Xian Chong Lu ◽  
Sun Fei Wang ◽  
Jing Zhe
Keyword(s):  
Surface Roughness ◽  
Electrical Discharge ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Wire Electrode ◽  
Machined Surface ◽  
Machined Surface Quality ◽  
New Process ◽  
Dry And Wet Conditions ◽  
Discharge Gap

This paper investigates a new process of wire electrical discharge machining (WEDM) as gas-liquid combined multiple cut. High-speed WEDM (HS-WEDM) finishing was compared in atmosphere and emulsion. Dry finishing has shorter discharge gap, better straightness and surface roughness and much higher material MRR than that in emulsion. Influences of wire winding speed and no load worktable feed on machined surface quality in dry and wet conditions were discussed. The better straightness obtained in gas is explained by analyzing forces acting on wire electrode. When first cut and second cut were performed both in emulsion liquid, and third cut was done in atmosphere, the surface roughness is improved compared with conventional WEDM.

scholarly journals Surface Roughness Analysis of H13 Steel during Electrical Discharge Machining Process Using Cu–TiC Sintered Electrode

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5943
Author(s):  
Arminder Singh Walia ◽  
Vineet Srivastava ◽  
Mayank Garg ◽  
Nalin Somani ◽  
Nitin Kumar Gupta ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Electrical Discharge ◽  
Pulse Current ◽  
Electrical Discharge Machining ◽  
Machining Process ◽  
H13 Steel ◽  
Machined Surface ◽  
Machined Surface Quality ◽  
Semi Empirical

In electrical discharge machining (EDM), the machined surface quality can be affected by the excessive temperature generation during the machining process. To achieve a longer life of the finished part, the machined surface quality plays a key role in maintaining its overall integrity. Surface roughness is an important quality evaluation of a material’s surface that has considerable influence on mechanical performance of the material. Herein, a sintered cermet tooltip with 75% copper and 25% titanium carbide was used as tool electrode for processing H13 steel. The experiments have been performed to investigate the effects of EDM parameters on the machined surface roughness. The findings show that, as the pulse current, pulse length, and pulse interval are increased, the surface roughness tends to rise. The most significant determinant for surface roughness was found to be pulse current. A semi-empirical surface roughness model was created using the characteristics of the EDM technique. Buckingham’s theorem was used to develop a semi-empirical surface roughness prediction model. The semi-empirical model’s predictions were in good agreement with the experimental studies, and the built empirical model based on physical features of the cermet tooltip was tested using dimensional analysis.

scholarly journals Influence of Gap Phenomenon on Various Kinds of Powder-Suspended EDM

2013 ◽  
Vol 7 (4) ◽  
pp. 419-425
Author(s):  
Hideki Takezawa ◽  
◽  
Tadashi Asano ◽  
Naotake Mohri ◽  
◽  
...  
Keyword(s):  
Surface Roughness ◽  
Electrical Discharge ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
High Speed Camera ◽  
Machined Surface ◽  
Machined Surface Roughness ◽  
Observation Results

Powder-suspended Electrical Discharge Machining (EDM) produces a mirror-like finish due to the electrical discharge dispersed using powder-suspended fluid. Machined surface roughness differed, however, when several powders are mixed, so the influence of the gap phenomenon was not apparent. To vary the gap phenomenon in powder-suspended EDM, the gap region is observed using a high-speed camera. This report describes observation results in powdersuspended EDM.

A Study of the Mechanism of Electrical Discharge Machining of Particle Reinforced Metal Matrix Composites with Concavo-Convex Electrode

2011 ◽  
Vol 480-481 ◽  
pp. 300-305
Author(s):  
Jiang Wen Liu ◽  
T.M. Yue ◽  
Zhong Ning Guo ◽  
Z. Y. Wan ◽  
G.Y. Liu
Keyword(s):  
Metal Matrix ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Processing Condition ◽  
Matrix Composites ◽  
Wire Electrode ◽  
Machined Surface ◽  
Particulate Reinforced ◽  
Stable Processing ◽  
Processing Mechanism

A new concavo-convex electrode has been designed and employed. And an analysis of the electrical discharge machining (EDM) mechanism of a particulate reinforced metal matrix composite with this new electrode was conducted in this study. It was found that EDM with this new electrode can accelerate the debris discharge during machining so that it has a higher MRR compared to the case where a normal electrode was employed. Moreover, by studying the surface craters, it could confirm that discharge craters tend to connect together for the normal electrode. This indicates an abnormal arcing condition. Thus, the wire electrode was easy to be broken. While for the new electrode, separated craters were observed on the machined surface. This means a stable processing condition. The experiment results reveal the processing mechanism of EDM electrical discharge machining of MMCs by employing this new electrode.

Direct Measurement of Electrode Movement During Electrical Discharge Machining by Means of Automatic Discharge Gap Controller

2010 ◽  
Vol 4 (6) ◽  
pp. 552-561 ◽  
Author(s):  
Masahiko Kita ◽  
◽  
Tohru Ishida ◽  
Yoshimi Takeuchi
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Power Supply ◽  
Research Group ◽  
Electrical Discharge ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Working Fluid ◽  
Method Of Measurement ◽  
Discharge Gap

This study deals with the development of a new method of directly measuring the movement of an electrode during normal electrical discharge machining (EDM) and the movement of an electrode during EDM by means of an automatic discharge gap controller (ADGC) devised by our research group. The ADGC, which mainly consists of a bidirectional actuator using a shape memory alloy (SMA) and an electrode and power supply for EDM, can sustain stable EDMby autonomously and automatically controlling the position of the electrode to keep the discharge gap appropriate. However, the movement of the electrode being controlled by the ADGC cannot be directly measured due to itsminute, high-speed, vibration-like movements inside the working fluid during EDM. This means that there is no way to prove that the ADGC actually controls the position of the electrode so as to maintain a suitable discharge gap for continuing stable EDM. This also means that there is no way to evaluate the movement of the electrode quantitatively and to design or optimize the structure of an ADGC so as to give the ADGC the desired or best performance. Therefore, a method to directlymeasure the electrodemovement by an ADGC is devised in this study. The results obtained in the measurement experiments using this method of measurement prove that the ADGC actually moves its electrode to achieve stable EDM, and they allow the movement of the electrode to be evaluated quantitatively.

scholarly journals Study on Surface Evenness of Super-high-thickness Cutting in High-speed Wire Electrical Discharge Machining

2021 ◽  
Author(s):  
Cong Deng ◽  
Zhidong Liu ◽  
Ming Zhang ◽  
Hongwei Pan ◽  
Mingbo Qiu
Keyword(s):  
Electrical Discharge ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Point Of View ◽  
Working Fluid ◽  
Wire Electrical Discharge Machining ◽  
Wire Electrode ◽  
Positional Accuracy ◽  
Vibration Absorption ◽  
The Wire

Abstract Surface machined by high-speed wire electrical discharge machining (HS-WEDM) at super-high thickness (more than 1000 mm) cutting suffers from uneven surface, a major problem that has been investigated in this paper. According to the analysis, as wire frame span increases, the rigidity of the wire electrode decreases, and under the action of discharge explosive force, wire electrode vibration intensifies. As a result, the machining stability inevitably decreases. However, the core problem is whether there is enough working fluid in the slit to dampen and absorb the vibration of the wire electrode so as to ensure the positional stability of the wire electrode. To verify the above point of view: first, the wire guide and gravity take-up with bidirectional tension in the wire feeding system were installed to improve the positional accuracy of the wire electrode; second, to improve the flow of the working fluid into the slit, the slit width was increased by improving the working fluid and a medium carrier with a higher melting point and vaporization point can reduce the vaporization of the working fluid in the slit as much as possible. The experiment showed that the outlet flow of the improved working fluid is 56.72% higher than that of the original working fluid when cutting a 750 mm thick workpiece, which increases the damping and vibration absorption effect of the working fluid on the wire electrode in the long and narrow gap. After the above measures were implemented, super-high thickness cutting can be carried out continuously and steadily, the surface evenness was significantly improved, and the workpiece with a thickness of 2000 mm was cut successfully.

scholarly journals Sliding abrasive wear when combining WEDM conditions and polishing treatment on H13 disks over 1045 carbon steel pins

2021 ◽  
Author(s):  
Antonio J. Sánchez Egea ◽  
Vitaliy Martynenko ◽  
Alejando Simoncelli ◽  
Gil Serrancoli ◽  
Daniel Martínez Krahmer
Keyword(s):  
Surface Roughness ◽  
Surface Properties ◽  
Electrical Discharge ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Wire Electrical Discharge Machining ◽  
Initial Surface ◽  
Friction Coefficients ◽  
Surface Conditions ◽  
Aisi 1045

AbstractForging dies are crucial in forging to manufacture accurate workpieces. These dies are generally made of AISI H steel series and hardened and tempered medium carbon alloy steel. Dies are processed by using high-speed milling + polishing or electrical discharge machining + polishing. The surface quality of the workpiece depends on the surface properties of these dies, where surface roughness, material hardness, and wear evolution of their surfaces are critical aspects to consider. This research analyzes different wire electrical discharge machining surface conditions combined with polishing treatment to describe their influence on friction and wear. Wire electrical discharge machining defines the disks’ surface properties in finishing and roughing conditions, and polishing treatment varies in time and paper sand depending on the roughness. Abbott-Firestone curves and Rsk-Rku roughness parameters characterize the surface roughness of each studied configuration. Room temperature pin-on-disk tests were performed to analyze friction coefficients and wear rate for AISI 1045 pins and AISI H13 disks. On average, the highest (0.284) and the lowest (0.201) friction coefficients were found for the combination of finishing wire electrical discharge machining + polishing and roughing wire electrical discharge machining conditions, respectively. Scanning electron microscope images were taken to describe the wear tracks and pin degradation for different sliding abrasive configurations. The diagram correlating the surface morphology and the friction coefficient predicts the wear damage on initial surface conditions, which is crucial in the forging industry to determine tool maintenance or replacement.

scholarly journals 302 Evaluation of Machined Surface Quality of Long Fiber FRM by Electrical Discharge Machining

2000 ◽  
Vol 2000.53 (0) ◽  
pp. 49-50
Author(s):  
Rikio HIKIJI ◽  
Yoshihiro KAWANO ◽  
Koji ABURADA ◽  
Masakazu HARADA ◽  
Minoru ARAI
Keyword(s):  
Surface Quality ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Machined Surface ◽  
Machined Surface Quality

Surface Study in a Non-conventional (Electrical Discharge Machining) Process for Grade 6 Titanium Material

2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Md. Ashikur Rahman Khan ◽  
M. M. Rahman
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Machining Process ◽  
Machined Surface ◽  
Titanium Material ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time

Electrical discharge machining (EDM) produces complex shapes and permits high-precision machining of any hard or difficult-to-cut materials. The performance characteristics such as surface roughness and microstructure of the machined face are influenced by numerous parameters. The selection of parameters becomes complicated. Thus, the surface roughness (Ra) and microstructure of the machined surface in EDM on Grade 6 titanium alloy are studied is this study. The experimental work is performed using copper as electrode material. The polarity of the electrode is maintained as negative. The process parameters taken into account in this study are peak current (Ip), pulse-on time (Ton), pulse-off time (Toff), and servo-voltage (Sv). A smooth surface finish is found at low pulse current, small on-time and high off-time. The servo-voltage affects the roughness diversely however, a finish surface is found at 80 V Sv. Craters, cracks and globules of debris are appeared in the microstructure of the machined part. The size and degree of craters as well as cracks increase with increasing in energy level. Low discharge energy yields an even surface. This approach helps in selecting proper process parameters resulting in economic EDM machining. 

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