MULTI-OBJECTIVE OPTIMIZATION IN WIRE-ELECTRICAL DISCHARGE MACHINING (WEDM) OF TITANIUM ALLOY

2015 ◽  
Vol 76 (6) ◽  
Author(s):  
J.B. Saedon ◽  
Norkamal Jaafar ◽  
Nor Hafiez Mohamad Nor ◽  
Mohd Azman Yahaya ◽  
Hazran Husain

This paper presents an investigation on influences and multiple optimizations of wire-electrical discharge (WEDM) machining performances such as cutting rate, material removal, surface roughness and kerf width processed on titanium alloy material. The experimental studies were conducted under varying machining parameters namely pulse-off time, peak current, wire tension and wire feed. The experimental works were designed base on Taguchi design of experiment. The optimum multi-objective performance characteristics was determined using analysis of variance (ANOVA) coupled with grey relational analysis (GRA). ANOVA was used to study the significance of process parameters on grey relational grade which showed the most significant factor. The grey relational grade obtained from GRA was used to optimize the wire-electrical discharge machining process. To validate the findings, confirmation experiment had been carried out using the optimal parameters and the predicted results were found in good agreements with experimental finding. Improved machining performance in the wire electrical machining process has been achieved by using this approach.

2015 ◽  
Vol 651-653 ◽  
pp. 738-743
Author(s):  
Oana Dodun ◽  
Vasile Merticaru ◽  
Laurenţiu Slatineanu ◽  
Margareta Coteaţă

The wire electrical discharge machining is a machining method able to allow detaching parts from plates type workpieces as a consequence of electrical discharges developed between workpiece and wire tool electrode found in a motion along its axis; there is also a work motion along the contour to be obtained. There are many factors able to exert influence on the sizes of parameters of technological interest. On the other hand, there are various methods that can be used in order to establish the optimal combination of the input factors, so that obtaining of machining best results is possible. When there are many process output factors, a problem of multiobjective optimization could be formulated. The Grey relational analysis method and the Taguchi method could be applied in order to optimize the wire electrical discharge machining process, when various criteria having distinct significances are considered. An experimental research was designed and developed in order to optimize the wire electrical discharge cutting of parts made of an alloyed steel, by considering six input factors: test piece thickness, pulse on time, pulse off time, wire axial tensile, current intensity and travelling wire electrode speed. As output parameters, one took into consideration surface roughness, wire tool electrode massic wear, cutting speed along the contour to be obtained. 16 experiments were developed in accordance with the requirements specific to a Taguchi table L16. The results of experiments were processed by means of Grey relational analysis method and Taguchi method.


2012 ◽  
Vol 576 ◽  
pp. 527-530
Author(s):  
Mohammad Yeakub Ali ◽  
W.Y.H. Liew ◽  
S.A. Gure ◽  
B. Asfana

This paper presents the estimation of kerf width in micro wire electrical discharge machining (micro WEDM) in terms of machining parameters of capacitance and gap voltage. An empirical model is developed by the analysis of variance (ANOVA) of experimental data. Using a wire electrode of 70 µm diameter, a minimum kerf width is found to be 92 µm for the micro WEDM parameters of 0.01 µF capacitance and 90.25 V gap voltage. Around 30% increament of the kerf is found to be high. The analysis also revealed that the capacitance is more influential parameter than gap voltage on kerf width produced by micro WEDM. As the gap voltage determines the breakdown distance and affects the wire vibration, the wire vibration factor is to be considered in the analysis and in formulation of model in future study.


Machines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 69
Author(s):  
Laurenţiu Slătineanu ◽  
Oana Dodun ◽  
Margareta Coteaţă ◽  
Gheorghe Nagîţ ◽  
Irina Beşliu Băncescu ◽  
...  

Wire electrical discharge machining has appeared mainly in response to the need for detachment with sufficiently high accuracy of parts of plate-type workpieces. The improvements introduced later allowed the extension of this machining technology to obtain more complex ruled surfaces with increasingly high requirements regarding the quality of the machined surfaces and the productivity of the wire electrical discharge machining process. Therefore, it was normal for researchers to be interested in developing more and more in-depth investigations into the various aspects of wire electrical discharge machining. These studies focused first on improving the machining equipment, wire electrodes, and the devices used to position the clamping of a wire electrode and workpiece. A second objective pursued was determining the most suitable conditions for developing the machining process for certain proper situations. As output parameters, the machining productivity, the accuracy, and roughness of the machined surfaces, the wear of the wire electrode, and the changes generated in the surface layer obtained by machining were taken into account. There is a large number of scientific papers that have addressed issues related to wire electrical discharge machining. The authors aimed to reveal the aspects that characterize the process, phenomena, performances, and evolution trends specific to the wire electrical discharge machining processes, as they result from scientific works published mainly in the last two decades.


Author(s):  
N Tosun ◽  
C Cogun

In this study, the effects of machining parameters on the wire wear, on the size of erosion craters on the wire and on the workpiece surface roughness were investigated experimentally in wire electrical discharge machining (WEDM). An attempt was made to correlate the crater volume and the pulse energy. The experiments were conducted under different settings of pulse duration, open-circuit voltage, wire speed and dielectric flushing pressure. The variations of the wire wear, the size of erosion craters on the wire and the workpiece surface roughness with machining parameters were modelled mathematically by using regression analysis. The relationship between the workpiece surface roughness and the crater size was established. The analysis of variance (ANOVA) and F-test were performed to obtain statistically significant process parameters and the percentage contribution of these parameters to the performance outputs.


2014 ◽  
Vol 984-985 ◽  
pp. 37-41
Author(s):  
N.E. Arun Kumar ◽  
A. Suresh Babu ◽  
V. Muthu Kumar

This paper investigates the relationship of process parameters in wire electrical discharge machining of titanium alloy with brass wire as tool electrode. Wire electrical discharge machining (WEDM) is used to cut conductive metals of any hardness or that difficult to cut with conventional methods. The process performances such as material removal rate (MRR) and surface finish (Ra) were evaluated by giving specific input parameters which practiced to obtain optimal response. The difficulty in machine tool industry is to predict the expected output performance for the desired input variables by the way of conducting more number of experiments for different machining parameters, which leads to the increase in consumption of electric power, material and time. To overcome this phenomenon, parametric investigation was made on WED machining on titanium alloy by using Taguchi’s method.


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