scholarly journals Experimental and Numerical Study of Crater Volume in Wire Electrical Discharge Machining

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 577 ◽  
Author(s):  
Jun Wang ◽  
José. A. Sánchez ◽  
Borja Izquierdo ◽  
Izaro Ayesta

Wire Electrical Discharge Machining (WEDM) is a popular non-conventional machining technology widely used in high-added value sectors such as aerospace, biomedicine, and the automotive industry. Even though the technology is now ready to meet the requirements of the most complex components, certain fundamental aspects related to the discharge process and gap conditions are not yet fully explained and understood. Combining single discharge experiments with numerical simulation represents a good approach for obtaining a deeper insight into the fundamentals of the process. In this paper, a fundamental study of the WEDM through single discharge experiments and numerical simulation is presented. WEDM single discharge experiments are described with the aim of identifying the relation between crater dimensions, discharge gap, and part surface roughness. A thermal transient numerical model of the WEDM process is presented, and correlation with actual industrial material removal rates (MRR) is analyzed. Results from single discharge WEDM experiments show that crater volume is as much as 40% lower when discharging on a rough surface than when the discharge occurs on a flat surface. The proposed thermal numerical model can predict actual removal rates of industrial machines with great accuracy for roughing cuts, deviations with experimental values being below 10%. However, lager deviations have been observed for other WEDM conditions, namely trim cuts, thus confirming the need for future research in this direction.

2012 ◽  
Vol 630 ◽  
pp. 114-120 ◽  
Author(s):  
Mamidala Ramulu ◽  
Mathew Spaulding ◽  
P. Laxminarayana

To improve strength to weight ratios, the fiber reinforced polymer composite materials are often used in conjunction with another material, like metals, to form hybrid structure. This paper reports the feasibility of using wire electrical discharge machining (WEDM) for cutting Titanium/Graphite Hybrid Composites (TiGr). Slit and slot cuts with WEDM process has been performed. Cutting times and process parameters were recorded, and cut surface characteristics were evaluated both with an optical and scanning electron microscopy (SEM). The results in terms of cutting time, workpiece material removal rate, and damage were presented and discussed. It was found that use of WEDM is possible for machining advanced hybrid metal composite laminates with appropriate machine settings.


Author(s):  
K H Ho ◽  
S T Newman ◽  
R D Allen

Over the last five years, a great deal of research effort has been concentrated on the development of a new data model ISO 14649, informally known as STEP-NC. It has been strongly argued that STEP-NC has huge implications on the integration of the computer-aided design/computer-aided process planning/computer-aided manufacture (CAD/CAPP/CAM) (CAx) systems, giving the opportunity to realize interoperable computer numerical control (CNC) manufacturing. This is largely owing to the data model, which provides the capability to revolutionize the current state of the art in CNC manufacturing by offering a bi-directional interface with a high-level description of the geometrical and manufacturing information. This paper provides a view of how these STEP-NC compliant information models can be used to support the wire electrical discharge machining (WEDM) CAD to the CNC process chain. The models are based on part 13 of the ISO 14649 standard, which is dedicated to the WEDM process, together with part 10 of the standard, which specifies the general machining information. The information models have been identified and their structures have been defined and modelled using the unified modelling language (UML). A STEP-NC compliant WEDM CAx prototype system, based on the Java and the object-oriented database management system (DBMS) ObjectStore, has been constructed with an example case study to demonstrate the information models.


2019 ◽  
Vol 12 (2) ◽  
pp. 107
Author(s):  
Fipka Bisono ◽  
Dhika Aditya P.

Wire electrical discharge machining(WEDM) banyak digunakan untuk proses pembuatan punch and dies. Dimana material yang digunakan memiliki tingkat kekerasan yang sangat tinggi. Parameter pemesinan yang kurang tepat dapat menyebabkan hasil pemotongan yang tidak optimal. Penelitian ini dilakukan untuk mengoptimalkan beberapa karakteristik hasil proses pemesinan secara serentak dengan cara mevariasikan variabel-variabel proses pemesinan WEDM. Karakteristik hasil proses yang diteliti antara lain adalah lebar pemotongan, kekasaran permukaan, dan tebal lapisan white layer. Proses pemesinan dilakukan pada material tool steel SKD 11. Arc on time, on time, open voltage dan servo voltage merupakan variabel-variabel proses yang akan divariasikan. Rancangan percobaan dilakukan menggunakan metode Taguchi dengan matriks ortogonal L18(21x33) dengan dua kali replikasi. Sedangkan langkah yang digunakan untuk mengoptimasi karakteristik hasil proses pemesinan yang diteliti secara serentak adalah menggunakan metode grey relational analysis (GRA). Lebar pemotongan, kekasaran permukaan dan tebal lapisan white layer memiliki performance characteristics “smaller-is-better.” Hasil dari penelitian menunjukkan nilai variabel-variabel proses pemesinan yang menghasilkan kualitas karakteristik yang paling optimum adalah sebagai berikut: arc on time (1A), on time (4?s), open voltage (70V), dan servo voltage (40V). Dengan persentase kontribusi variabel proses dari yang terbesar berturut-turut adalah on time (65,09%), open voltage (11,35%), arc on time (7,71%), dan servo voltage (5,61%). Wire electrical discharge machining (WEDM) process is commonly used to make punch and dies. WEDM services are typically used to cut hard metals. Inappropriate machining parameters can cause suboptimal cutting results. This research was conducted to optimize several characteristics of the machining process simultaneously by varying WEDM machining process variables. Performance characteristics of the WEDM process include the kerf, surface roughness and thickness of the white layer. The machining process is carried out on SKD 11 tool steel material.  Arc on time, on time, open voltage and servo voltage are process variables that will be varied. The experimental matrix design was carried out using the Taguchi method L18 (21x33) orthogonal array with two replications. Then to optimize the performance characteristics of the machining process simultaneously is using the Gray Relational Analysis (GRA) method. Performance characteristics of kerf, surface roughness, and thickness of the white layer is "smaller-is-better". The results of the experiment indicate the value of the machining process variables that produce the most optimum quality performance characteristics are as follows: arc on time (1A), on time (4?s), open voltage (70V), and servo voltage (40V). And the percentage of contribution of the process variables from the largest to smallest are as follows: on time (65,09%), open voltage (11,35%), arc on time (7,71%), and servo voltage (5,61%).


Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 454 ◽  
Author(s):  
Arkadeb Mukhopadhyay ◽  
Tapan Barman ◽  
Prasanta Sahoo ◽  
J. Davim

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.


2016 ◽  
Vol 15 (02) ◽  
pp. 85-100 ◽  
Author(s):  
P. C. Padhi ◽  
S. S. Mahapatra ◽  
S. N. Yadav ◽  
D. K. Tripathy

The present work is aimed at optimizing the cutting rate (CR), surface roughness (Ra) and dimensional deviation (DD) in wire electrical discharge machining (WEDM) of EN-31 steel considering various input parameters such as pulse-on-time, pulse-off-time, wire tension, spark gap set voltage and servo feed. A face centered central composite design of response surface methodology (RSM) has been adopted to develop the empirical model for the responses. It is often desired to obtain a single parameter setting that can decrease Ra and DD and increase CR simultaneously. Since the responses are conflicting in nature, it is difficult to obtain a single combination of cutting parameters satisfying all the objectives in any one solution. The optimum search of the machining parameter values for maximization of CR and minimization of Ra and DD are formulated as a multi-objective, multi-variable, nonlinear optimization problem using genetic algorithm weighted sum method to evaluate the performance.


2012 ◽  
Vol 507 ◽  
pp. 180-183 ◽  
Author(s):  
Cun Shan Xu

Wire electrical discharge machining (WEDM) is an advanced thermal machining process capable of accurately machining parts with complicated shapes, especially for the parts that are very difficult to be machined by traditional machining processes. WEDM process is based on the conventional EDM sparking phenomenon utilizing the widely accepted non-contact technique of material removal. Since the introduction of the process, WEDM has evolved from a simple means of making tools and dies to the best alternative of producing micro-scale parts with the highest degree of dimensional accuracy and surface finish quality. This author reviews the vast array of research work carried out from the EDM process to the development of the WEDM, also highlights the working principle and mechanical performance of machining conditions. A wide range of WEDM industrial applications are reported together with the development of the hybrid machining processes. The final part of the paper discusses these developments and outlines the possible trends for future WEDM research.


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