scholarly journals Dynamic Control of Discharge Energy During WEDM for the Purpose of Eliminating Vibrations of the Wire Tool Electrode

2021 ◽  
Vol 29 (4) ◽  
pp. 260-265
Author(s):  
Ľuboslav Straka ◽  
Patrik Kuchta
Keyword(s):  
Electrical Discharge Machining ◽  
Production Systems ◽  
Dynamic Control ◽  
High Strength ◽  
Tool Electrode ◽  
Discharge Process ◽  
Machined Surface ◽  
The Wire ◽  
Wedm Process

Abstract Production in all industry fields is currently affected by new scientific and technical knowledge and the requirements for its rapid deployment. In many cases, the most modern and highly sophisticated technical systems are applied. Simultaneously, fully automated production systems are rather successfully used and progressive production technologies are implemented. In most cases, there is an integral part of a management system that operates the challenging technological processes. These processes would not be executable without the system’s precise control, which provides a suitable precondition for ensuring the high quality of manufactured products. However, the customer’s demanding requirements are not always met. These involve increased requests for the quality of the final product due to the reduction of the tolerance band and application of high-strength materials. This paper aims to describe one of the solutions by which it is possible to achieve a higher quality of the machined surface after wire electrical discharge machining (WEDM). The solution proposes that through dynamic management, the WEDM process eliminates the vibrations of the wire tool electrode and thereby achieves a substantial increase in the quality of the eroded area in terms of its geometric accuracy. With the support of an extensive database of information with precise exchange of information, the proposed system will allow to control the electro discharge process with regard to the optimal way of operation of the electro discharge machine on the basis of individually selected conditions.

scholarly journals Adjustment of Wire Vibrations in Order to Improve Geometric Accuracy and Surface Roughness at WEDM

2021 ◽  
Vol 11 (11) ◽  
pp. 4734
Author(s):  
Ľuboslav Straka ◽  
Ivan Čorný
Keyword(s):  
Surface Roughness ◽  
Economic Efficiency ◽  
Acoustic Emissions ◽  
Tool Electrode ◽  
Geometric Accuracy ◽  
Dynamic Adjustment ◽  
Machined Surface ◽  
Minimal Impact ◽  
The Wire ◽  
Wedm Process

Although WEDM is one of the most precise finishing technologies, deviations from the required geometric shapes and surface roughness occur in the production of parts with rotary surfaces. Even though these shortcomings have only a minimal impact on planar cuts, the production of circular profiles is a different problem. One of the factors causing this poor quality is the vibration of the wire electrode. With appropriate vibration adjustment, it would be possible to achieve significant improvements of the eroded area quality, both in terms of geometric accuracy and in terms of surface roughness. This would significantly increase quality, enabling WEDM technology to compete with other technologies in terms of economic efficiency. Therefore, the proposed solution aims to provide a partial adjustment to the wire tool electrode vibrations, based on their sensing by the means of acoustic emissions or a laser beam, with subsequent dynamic adjustment of the actual technological parameter values. This way, the given solution will increase the production accuracy of circular holes, increase productivity, and ultimately provide an overall increase in the economic efficiency of the WEDM process. The article also presents the scheme of a control algorithm for monitoring and subsequent adjustments of the vibrations of the wire tool electrode during the electroerosion process in order to minimize geometric deviations of circularity, cylindricity and roughness of the machined surface.

Benefits of Using Diamond Dies for Cold Alternate Drawing of Magnesium Alloys

2016 ◽  
Vol 716 ◽  
pp. 13-21 ◽  
Author(s):  
Vladimir Stefanov Hristov ◽  
Kazunari Yoshida
Keyword(s):  
Magnesium Alloy ◽  
Weight Ratio ◽  
High Strength ◽  
Wire Drawing ◽  
High Ductility ◽  
Element Analysis ◽  
The Wire ◽  
Shearing Strain ◽  
Drawing Method

In recent years, due to its low density and high strength/weight ratio, magnesium alloy wires has been considered for application in many fields, such as welding, electronics, medical field (for production of stents). But for those purposes, we need to acquire wires with high strength and ductility. For that we purpose we proposed alternate drawing method, which is supposed to highly decrease the shearing strain near the surface of the wire after drawing, by changing the direction of the wire drawing with each pass and thus acquiring high ductility wires.We have done research on the cold alternate drawing of magnesium alloy wires, by conducting wire drawing of several magnesium wires and testing their strength, hardness, structure, surface and also finite element analysis, we have proven the increase of ductility at the expense of some strength.In this research we are looking to further improve the quality of the drawn wires by examining the benefits of using diamond dies over tungsten carbine dies. Using the alternate drawing method reduces the strength of the drawn wires and thus lowering their drawing limit. By using diamond dies we are aiming to decrease the drawing stress and further increase the drawing limit of the alternate drawn wires and also improve the quality of the finishing surface of the wires. With this in mind we are aiming to produce a good quality wire with low diameter, high ductility, high strength and fine wire surface.

Research on Electrical Discharge Machining for Injection Mold of Automotive Connector

2012 ◽  
Vol 522 ◽  
pp. 17-20
Author(s):  
Wei Min Pan ◽  
Ke Ke Shi ◽  
Xian Qing Lei
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Tool Electrode ◽  
Injection Mold ◽  
Workpiece Material ◽  
Electrode Tool ◽  
Mating Surface ◽  
Plastic Components

Electrical discharge machining (EDM) processing is generally applied on the area of molding plastic component or mating surface required high accuracy. The areas determine the quality of the plastic components. The principle of EDM is based on the material vaporization of high potential difference across the workpiece and Tool electrode. Tool electrode and workpieces are discontiguous when the EDM processes. Because there is no mechanical contact, Hardness and strength of the workpiece material have minimal effect on the material removal rate .The application of EDM technology on injection mold of automotive connector is focused on in this paper. Processing of the complex cores is researched. The design and processing of the tool electrode have been completed in the meantime.

Electrical Discharge Machining of Submicron-Diameter Micropins

2010 ◽  
Vol 447-448 ◽  
pp. 238-241 ◽  
Author(s):  
Hiromitsu Ueno ◽  
Yuki Kono ◽  
Kai Egashira
Keyword(s):  
Electrical Discharge ◽  
Tungsten Wire ◽  
Open Circuit Voltage ◽  
Pulse Generator ◽  
Electrical Discharge Machining ◽  
Open Circuit ◽  
Tool Electrode ◽  
Stray Capacitance ◽  
Finish Machining ◽  
The Wire

The wire electrodischarge grinding (WEDG), which is one of the electrical discharge machining (EDM) methods, of submicron-diameter zinc micropins was attempted using a relaxation-type pulse generator. Tungsten wire of 30 µm diameter was employed as the tool electrode. The open-circuit voltage was set at lower than or equal to 15 V in the finish machining step. The electrostatic capacitance of the pulse generator was its stray capacitance only. As a result, a micropin of 0.3 µm diameter was processed. They are the smallest-diameter micropins fabricated by EDM, to the best of our knowledge.

scholarly journals QUALITY OPTIMIZATION OF THE MACHINED SURFACE IN TERMS OF ELECTRIC ENERGY CONSUMPTION IN THE WEDM PROCESS

2021 ◽  
Vol 2021 (2) ◽  
pp. 4400-4407
Author(s):  
LUBOSLAV STRAKA ◽  
◽  
PATRIK KUCHTA ◽  
Keyword(s):  
Energy Consumption ◽  
Production Process ◽  
Electric Energy ◽  
Quality Parameters ◽  
Machining Process ◽  
Discharge Energy ◽  
Machined Surface ◽  
Electric Energy Consumption ◽  
Wedm Process

Current engineering production is characterized by ever-increasing requirements for the final quality of products. But high fabrication productivity is required in many cases as well. Another advantage is, of course, a beneficial economic efficiency of the production process. However, despite the advanced technical level of production and extensive knowledge in the field of electro-erosive machining, in many cases, the overall efficiency of the production process is based on the skills of operators. Besides, insufficiently experienced production operators sometimes still use the trial and error system, even today. A comprehensive set of information for selecting optimal conditions of the electric discharge machining process with the possibility of practical application in real conditions of practice is currently non-existent. The paper therefore describes the experimental measurements performed in order to optimize the quality of the machined surface with respect to electric energy consumption in the WEDM process. In contrast to current approaches, the solution of the issue relied on determining the relationship between the performance parameters of the process and its controllable output quality parameters so that they would be applicable to the conditions of real practice. It was found that with the reduction of discharge energy through individual WEDM operations, the quality indicators in terms of roughness parameters improve. However, on the other hand, reducing the discharge energy leads to a significant increase in the total electric energy consumption. Therefore, the aim of the performed optimization was to look for a suitable type of WEDM operation, in which a favourable value of the roughness of the eroded surface is achieved while maintaining favourable electric energy consumption.

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

scholarly journals Multi-Response Optimization of WEDM Process Parameters for Machining of Superelastic Nitinol Shape-Memory Alloy Using a Heat-Transfer Search Algorithm

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1277 ◽  
Author(s):  
Rakesh Chaudhari ◽  
Jay J. Vora ◽  
S. S. Mani Prabu ◽  
I. A. Palani ◽  
Vivek K. Patel ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Process Parameters ◽  
Discharge Process ◽  
The Wire ◽  
Pulse On Time ◽  
Wedm Process

Nitinol, a shape-memory alloy (SMA), is gaining popularity for use in various applications. Machining of these SMAs poses a challenge during conventional machining. Henceforth, in the current study, the wire-electric discharge process has been attempted to machine nickel-titanium (Ni55.8Ti) super-elastic SMA. Furthermore, to render the process viable for industry, a systematic approach comprising response surface methodology (RSM) and a heat-transfer search (HTS) algorithm has been strategized for optimization of process parameters. Pulse-on time, pulse-off time and current were considered as input process parameters, whereas material removal rate (MRR), surface roughness, and micro-hardness were considered as output responses. Residual plots were generated to check the robustness of analysis of variance (ANOVA) results and generated mathematical models. A multi-objective HTS algorithm was executed for generating 2-D and 3-D Pareto optimal points indicating the non-dominant feasible solutions. The proposed combined approach proved to be highly effective in predicting and optimizing the wire electrical discharge machining (WEDM) process parameters. Validation trials were carried out and the error between measured and predicted values was negligible. To ensure the existence of a shape-memory effect even after machining, a differential scanning calorimetry (DSC) test was carried out. The optimized parameters were found to machine the alloy appropriately with the intact shape memory effect.

Electric Discharge Machining of Cryo-Treated BeCu Alloys

2015 ◽  
Vol 787 ◽  
pp. 386-390
Author(s):  
Sandeep Chinke ◽  
Vijaykumar S. Jatti ◽  
T.P. Singh
Keyword(s):  
Tool Wear ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Cryogenic Treatment ◽  
High Strength ◽  
Machining Process ◽  
Tool Electrode ◽  
Severe Problem ◽  
Magnetic Strength ◽  
Conventional Machining

Beryllium copper possesses high strength which produces severe problem of surface integrity and tool wear during machining by conventional machining process. Electrical discharge machining is a practically viable option to solve this problem. The present study investigates the effect of cryogenic treatment of work part along with gap current and external magnetic field on material removal rate (MRR) and tool wear rate (TWR). Blind 3 mm square holes were produced using electrolytic copper tool electrode to machine cryo-treated BeCu and untreated BeCu. Gap current is varied from 8 A to 16 A in a step of 2 amperes and magnetic strength is varied from 0 to 0.496 T in a step of 0.124 T. Based on the experimental results it was found that MRR increases with increase in gap current for both untreated BeCu and treated work part. Plotted graphs of cryo-treated work part showed high values of MRR in comparison to untreated work part. TWR increases for both treated and untreated BeCu work part with increase in gap current. But the TWR was less for cryo-treated work part in comparison to untreated work part. MRR and TWR increases for both treated and untreated BeCu work part with increasing magnetic strength. Again the MRR was found higher with lower TWR for treated workpiece with regard to magnetic strength. Thus it can be concluded that cryogenic-treatment with magnetic strength improves EDM machining efficiency.

scholarly journals Modeling and Optimization of Fractal Dimension in Wire Electrical Discharge Machining of EN 31 Steel Using the ANN-GA Approach

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 454 ◽  
Author(s):  
Arkadeb Mukhopadhyay ◽  
Tapan Barman ◽  
Prasanta Sahoo ◽  
J. Davim
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Fractal Dimension ◽  
Process Parameters ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Wire Electrical Discharge Machining ◽  
Machining Parameters ◽  
Machined Surface ◽  
Wedm Process

To achieve enhanced surface characteristics in wire electrical discharge machining (WEDM), the present work reports the use of an artificial neural network (ANN) combined with a genetic algorithm (GA) for the correlation and optimization of WEDM process parameters. The parameters considered are the discharge current, voltage, pulse-on time, and pulse-off time, while the response is fractal dimension. The usefulness of fractal dimension to characterize a machined surface lies in the fact that it is independent of the resolution of the instrument or length scales. Experiments were carried out based on a rotatable central composite design. A feed-forward ANN architecture trained using the Levenberg-Marquardt (L-M) back-propagation algorithm has been used to model the complex relationship between WEDM process parameters and fractal dimension. After several trials, 4-3-3-1 neural network architecture has been found to predict the fractal dimension with reasonable accuracy, having an overall R-value of 0.97. Furthermore, the genetic algorithm (GA) has been used to predict the optimal combination of machining parameters to achieve a higher fractal dimension. The predicted optimal condition is seen to be in close agreement with experimental results. Scanning electron micrography of the machined surface reveals that the combined ANN-GA method can significantly improve the surface texture produced from WEDM by reducing the formation of re-solidified globules.

High Precision Femtosecond Laser Micromachining for Rapid Manufacture of MEMS Devices

2003 ◽  
Author(s):  
A. Bulusu ◽  
S. P. Joshi ◽  
P. S. Shiakolas
Keyword(s):  
Electrical Discharge Machining ◽  
Beam Quality ◽  
Focal Length ◽  
Chemical Vapor ◽  
Laser Micromachining ◽  
Inert Gases ◽  
Mems Devices ◽  
Machined Surface ◽  
Rapid Manufacture

Laser assisted machining in the MEMS context is gaining recognition due to its versatility in application and its cost effectiveness compared to processes such as LIGA, chemical vapor deposition, electrical discharge machining etc. High thermal conductivity causes instant heat transfer to the surroundings leading to significant heat affected zones. Damage to the surroundings is further aggravated by high ablation thresholds for metals when excimer lasers are used. Ultrashort pulse lasers have been found to minimize thermal damage to the surroundings more than any other known laser. Peak power densities cause direct evaporation and plasma formation of the material. High-pressure shock waves at the machined surface transfer the particles away from the spot preventing material redeposition around the feature. In this paper, we explore the use of femtosecond lasers for rapid manufacturing of MEMS devices through laser micromachining of master molds that can be used in replication processes such as hot embossing and injection molding. The effect of various factors that affect the size and quality of the machined feature such as beam quality, length of beam path, beam waist, polarization, energy per pulse and focal length of the lens used is investigated. The effect of various materials along with the use of vacuum and inert gases on the quality of the cut is also This work aims at laying the foundation for the development of a comprehensive database on the effect of various factors that need to be considered in the design of a laser micromachining system for rapid manufacture of MEMS devices.

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