Wire Electrical Discharge Machining Parameters Research Articles

Exploration on WEDM process parameters effect on LM13 alloy and LM13/SiC composites using Taguchi method

In manufacturing sectors and the automobile field’s aluminium and aluminium based composites usage in various range of applications owing to their higher physical and mechanical properties. Wire electrical discharge machining process is a highly complex, time varying & stochastic process. The process output is affected by input variables. Therefore a suitable selection of input variables for the wire electrical discharge machining (WEDM) process relies heavily on the operator's technology & experience due to wide range of demand. Metal removal rate (MRR) & surface finish (Ra) are sought to obtain precision work. Using Taguchi's parameter design, significant machining parameters affecting the performance measures are identified as pulse off time (Toff), pulse on time (Ton) and input current (amps). In the present study, first experimentation on LM13 aluminium alloy and LM13/SiC composites has been fabricated by squeeze casting process under optimal parametric condition to attain better hardness and tensile strength. In second phase of examination the machinability study were carried out of LM13 alloy and LM13/SiC composites through WEDM techniques input process variables such as pulse on time (Ton, 30–40 µs), pulse off time (Toff, 4–10 µs) and peak current (Ip, 1–3 Amp) on response of material removal rate (MRR) and surface roughness (Ra). The L9 OA Taguchi method was implemented for calculating the machining characteristics. The effect of each control factor on the performance measure is studied individually using the plots of signal to noise (S/N) ratio. The study demonstrates that the WEDM process parameters can be adjusted so as to achieve better metal removal rate and surface finish. Therefore, the optimal set of WEDM parameters is suggested for all manufacturing sectors.

Multi-objective parametric optimization on machining of Inconel-825 using wire electrical discharge machining

Wire electrical discharge machining is a thermal energy-based non-conventional machining process which can machine conductive materials with high precision. In this present work, machining of Inconel-825 was performed using wire electrical discharge machining. Multi-objective parametric optimization was performed for maximum cutting rate and minimum surface roughness using teaching–learning-based optimization, grey relational analysis, and genetic algorithm. Four wire electrical discharge machining parameters, namely spark off time (SOFF), spark on time (SON), peak current (IP), and angle of cutting (A) were considered. Comparison of optimum wire electrical discharge machining parameters through teaching–learning-based optimization, grey relational analysis, and genetic algorithm was performed. The better optimum solution for wire electrical discharge machining parameters was obtained using teaching–learning-based optimization and optimum values were at IP (1 A), SON (30 µs), SOFF (12.5 µs), and A (44.8°) with cutting rate as 19.744 mm/min and surface roughness as 1.331 µm. The optimum results obtained using optimization techniques were validated with the experimental results and error was observed to be within 5%. Moreover, response surface models were developed to predict the cutting rate and surface roughness in terms of wire electrical discharge machining parameters using analysis of variance.

Optimization of WEDM process parameters in machining Nimonic 75 alloy using brass wire

PurposeAn experimental study has been conducted to model and optimize wire electric discharge machining (WEDM) process parameters such as pulse-on time, pulse-off time, servo voltage and peak current for response characteristics during machining of Nimonic 75 alloy.Design/methodology/approachThe response surface methodology (RSM)-based Box–Behnken's design has been employed for experimental investigation. RSM is used for developing quadratic regression models for selected response variables i.e. material removal efficiency and kerf width. To validate the model, confirmation experiments have been performed. The multi-response optimization has been done using desirability function approach.FindingsThrough analysis of variation, the percent contribution of process parameters on the response characteristics has been found. Pulse-off time is the most significant parameter affecting the kerf width and material removal efficiency followed by pulse-on time. The quadratic regression models have been developed for prediction of selected response variables. An attempt has been made to optimize the WEDM parameters for material removal efficiency and kerf width. The recommended process parameter setting for maximum material removal efficiency and minimum kerf width have been found to be pulse-on time = 0.6 µs, pulse-off time = 14 µs, servo voltage = 25 V and peak current = 200 A.Originality/valueThe “kerf width” is an important response variable for maintaining dimensional accuracy of the machined component, but has not been given due attention by the researchers. In the present work, the developed regression model for “kerf width” can be used in estimating wire offset setting and thereby getting a dimensionally accurate product. The optimum process parameters obtained in WEDM of Nimonic 75 alloy will contribute in database of machining. The outcome of this study would be added to scare database of the machining of Nimonic 75 alloy and also would be extremely useful for making the technology charts for WEDM.

Surface Integrity of Ni-Rich NiTi Shape Memory Alloy at Optimized Level of Wire Electric Discharge Machining Parameters

The concern of this experimental work is to study the surface integrity aspects such as surface morphology, three-dimensional surface topography, recast layer, phase analysis, and micro-hardness for Ni55.95Ti44.05 shape memory alloy at the optimized level of wire electric discharge machining parameters. A mathematical model was developed for surface roughness and material removal rate considering servo voltage, pulse on time, wire tension, wire feed rate, and pulse off time using response surface methodology technique. In order to obtain the optimized parameters, multi-objective optimization technique grey relation analysis was utilized. The adequacy of the developed model was also checked by analysis of variance. At optimal parameters setting, i.e., pulse on time 123 µs, pulse off time 58 µs, servo voltage 50 V, wire tension 3 N, and wire feed rate 5 m/min, maximum material removal rate (8.223 mm3/min) and minimum surface roughness (1.93 µm) were achieved. Surface characteristics of machined surface divulge the presence of discharge craters, debris, molten droplets, micro-voids, spherical nodules, and cracks. A recast layer of thickness 19 µm with approximately 21% of foreign elements was deposited on the machined surface at optimized parameters, whereas the micro-hardness of the outer machined surface was found to be increased approximately 1.98 times as compared to micro-hardness of bulk material. X-ray diffraction analysis shows the presence of the following compounds on the machined surface NiTi, Ni4Ti3, Ti4O3, Cu5Zn8, Ni(TiO3), and NiZn.

Detailed Experimental Investigations on Machinability of EN31 Steel by WEDM

EN31 steel is a potential member in automobile industry, and achieving dimensional accuracy with outstanding surface characteristics is a challenging task while machining this alloy. The current investigations deal with wire electrical discharge machining (WEDM) of EN31 die steel and establish a fundamental understanding of the process parameters on micro-scale machined surface characteristics. WEDM parameters such as pulse on-time, servo voltage, wire feed and wire tension are grouped in an efficient way to understand the influence of these parameters on edge roughness, kerf width and cutting rate. The current study revealed that low pulse on-time and servo voltage decreased kerf width and edge roughness. However, cutting rate decreased with pulse on-time but increased with servo voltage. Wire tension and wire feed were found to have diverse effects on the response parameters. While edge roughness varied inversely, kerf width was directly proportional to the wire feed corresponding to lower wire tension.

Performance and Surface Integrity of Wire Electrical Discharge Machining of Thin Ti6al4v Plate Using Coated and Uncoated Wires

Wire Electrical Discharge Machining (WEDM) is one of the most important production technologies to manufacture very accurate small components and tools on any electrical conductive material. Titanium and its alloys have been widely used in automobile and aerospace industry as well as in medical engineering field. Small components and tools with complex geometrical shapes are difficult to be produced on titanium alloys by both conventional and nonconventional machining technologies. In this work an experimental investigation on the influences of wire electrode type and electrical variables when WEDM a thin plate of Ti6Al4V alloy has been carried out. Uncoated brass wire and copper wire with a diffused zinc coating were used for the experiments. Interval time, wire run-off speed, discharge duration and dielectric inlet pressure were evaluated in order to achieve adequate process parameter settings. Characteristics of surface integrity were also investigated. The best technological results for all tested WEDM parameters were attained for copper wire with a diffused zinc coating. The recast layer of the samples WEDMachined with the copper wire presented a smaller thickness and more compact than that obtained with uncoated brass wire. For WEDM with both types of wire, the existence of thermal cracks was observed.

Optimization of WEDM Process Parameters for Cutting Speed using Taguchi technique

Abstract In this present experimental study, the effect and advancement of machining parameters on cutting speed in wire electrical discharge machining (WEDM) operations were studied. The hybrid metal matrix composite (MMC) was manufactured by process named as stir casting utilizing particulates of Silicon carbide and graphite each in Al6061 combination. The analyses were outlined with Taguchi L27 design matrix. WEDM parameters resemble pulse (PU) on time, current, PU off time, gapset voltage, wire tension and wire feed are considered. The impact of parameters on the cutting speed (CS) is dictated by utilizing examination of fluctuation. The optimized parameters are PU on time (Level 3), PU off time (Level 1), peak current (Level 2), gap set voltage (Level 1), wire feed (Level 3) and wire tension (Level 2) are the best combination to achieve best cutting speed. PU off time, set voltage, PU on time and discharge current have considerable effect and most influenced control parameters on CS

Analyzing wire deflection errors of WEDM process on small arced corners

Wire electrical discharge machining (WEDM) is an advanced machining process capable of precise machining of parts with complicated shapes. Machining inaccuracy at small arced corners is a major problem of WEDM process. It is aimed to develop a novel mathematical methodology validated by experimental data for analyzing the wire deflection and evaluating total machining errors of arced corners during the WEDM process. The maximum spark gap, spark angle around the wire, spark forces applied to the wire and the resulting deflection are mathematically described based on the nature of the electrical discharge process and plasma channel properties to clarify the causes of wire deflection error in the small arced corners. The influence of the driving WEDM parameters, including discharge frequency and wire tension, are theoretically and experimentally studied in regard to the wire deflection and total machining errors for various experimental sets. Finally, the estimated wire deflection and total machining errors are compared and evaluated. The results indicate that wire deflection error is one of the major causes of machining errors in the arced corners; this error is almost 57% of the total machining error. In addition, the effect of wire vibration and excitation of discharges on the total machining errors are mentioned. According to the results, it is concluded that the proposed theoretical formulations can be used for prediction and compensation of wire deflection errors in the arced corner machining.

Experimental Investigation and Optimization of Machining Parameters in WEDM of Nano-SiC Particles Reinforced Magnesium Matrix Composites

Among various machining processes, wire electrical discharge machining (WEDM) is regarded as one of the efficient and cost-effective processes in machining of metal matrix nanocomposites (MMNC). This article discusses the investigation and optimization of machining parameters like the voltage, pulse off time, pulse on time, wire feed rate and wt% nano-SiC particles in WEDM of magnesium metal matrix nanocomposites. Experiments are conducted on magnesium reinforced with nano-silicon carbide particles of diameter 50-80 nm. Machining parameters like the voltage, pulse off time, pulse on time, wire feed rate and wt% nano-SiC are considered for the investigation using a four-factor D-optimal design based on the response surface methodology. The WEDM performances of MMNCs are evaluated by employing the parameters like metal removal rate (MRR) and surface roughness (SR). The second order quadratic models are developed between WEDM parameters and responses by regression analysis. The derived mathematical models are then optimized using the multi-objective optimization technique based on desirability analysis. The investigation indicates that the predicted values of the obtained model are in accordance with the experimental values. Surface morphology and the effects of nanoparticle reinforcement in the machined surface are observed through SEM micrographs.

Electric Discharge Machining of Tungsten Carbide using Uncoated and Coated Wire Electrodes: Analysis of Cutting Speed and Workpiece Geometrical Accuracy

Tungsten carbide is an important tool and die material due to its excellent mechanical properties such as high hardness, good toughness, and wear resistance. Wire electric discharge machining (WEDM) is regarded as a process capable of machining complex geometries and curved features in difficult-to-cut tungsten carbide. The present research work is carried out to study the influence of wire electrode, workpiece taper angle, and WEDM parameters on cutting speed and geometrical error of curved profile machined in tungsten carbide. Experiments are performed based on Taguchi’s L18 orthogonal array using two types of wires; uncoated brass wire and zinc-coated brass wire. Experimental results indicate that zinc-coated brass wire offers higher cutting speed as compared to uncoated brass wire. Main effects plots show that pulse-on time and pulse-off time are the most significant factors affecting cutting speed while taper angle is the most significant factor for geometrical error.

Experimental investigation of WEDM process parameters for cutting speed using response surface methodology

In this present experimental study, the effect and advancement of machining parameters on cutting speed (CS) in wire electrical discharge machining (WEDM) operations were studied. The hybrid metal matrix composite (MMC) was manufactured by process named as stir casting utilizing particulates of Silicon carbide and graphite each in Al6061 combination. The analyses were outlined with response surface methodology. WEDM parameters resemble Pulse on time, current, Pulse off time and control speed are considered. The optimized parameters are Pulse on time (Level 3), Pulse off time (Level 1), peak current (Level 2) and control speed (Level 2) are the best combination to achieve best material removal rate. Pulse off time, control speed, Pulse on time and discharge current have considerable effect and most influenced control parameters on CS.

Optimization of WEDM Process Parameters on Machining of AZ91 Magnesium alloy using MOORA method

Selection of optimum machining parameters in wire electrical discharge machining (WEDM) operations leads to good functional attributes for the machined components and increased productivity. In this present experimental work, the effect and advancement of machining control parameters over kerf and cutting speed in wirecut electrical discharge machining operations were analyzed. Multi objective optimization by ratio analysis (MOORA) applied for optimization of kerf width (KW) and cutting speed (CS). Magnesium AZ91 alloy is selected as work material of dimension 100 x 100 x 10 mm. The analyses were outlined with Taguchi L27 design matrix. WEDM parameters resemble Pulse on time, Pulse off time, current, gap voltage, wire speed & wire tension are considered. The effect of the cutting control parameters on the kerf width and cutting speed is directed by using examination of fluctuation. The parameters corresponding to experiment run number 2 are pulse on duration 106 units (Level 1), pulse off duration40 units (Level 1), peak pulse current 150 units (Level 2), gap voltage30 units (Level 2), wire feed 6 units (Level 2) & wire tension 8 units (Level 2) are the best combination to achieve better CS and KW.

Effects of Process Parameters on Material Removal Rate and Surface Roughness in Wedm of H-13 Die Tool Steel

In research work variation of cutting performance with pulse on time, pulse off time, wire type, and peak current were experimentally investigated in wire electric discharge machining (WEDM) process. Soft brass wire and zinc coated diffused wire with 0.25 mm diameter and Die tool steel H-13 with 155 mm× 70 mm×14 mm dimensions were used as tool and work materials in the experiments. Surface roughness and material removal rate (MRR) were considered as performance output in this study. Taguchi method was used for designing the experiments and optimal combination of WEDM parameters for proper machining of Die tool steel (H-13) to achieve better surface finish and material removal rate. In addition the most significant cutting parameter is determined by using analysis of variance (ANOVA). Keywords Machining, Process Parameters, Material removal rate, Surface roughness, Taguchi method

Surface hardenability studies of the die steel machined by WEDM

ABSTRACTThe mechanical properties of steels are well known to be sensitive to the surface treatments or alterations in the surface morphology and the subsurface. The current work attempts to perform the surface/subsurface modifications of the die steel using wire electric discharge machining (WEDM). The effects of WEDM parameters such as servo feed (SF) and wire speed (WS) on the recast layer formation have been discussed. Detailed scanning electron microscopy (SEM) was conducted to observe the nature of the recast layer formed. SEM-energy dispersive X-ray line-scan analysis suggests that the thickness of the recast layer increases with the increase in the WS, for a given SF of the WEDM. The elemental line scan reveals the presence of C, Cr, Cu along with Fe in the recast layer. Microhardness was measured across the recast layer to evaluate the effects of WEDM parameters on the hardenability of the die steel. Results divulge the increase in the surface and subsurface hardness of the die steel due to WEDM. The mechanism of surface hardening involved in the current work is discussed herein.

A Fuzzy approach to trim down the struggles in machining of AMMC by means of optimization of the Surface Roughness and Kerf Width

Aluminum Metal Matrix Composites (AMMCs) are the precise resources for aerospace, defense, marine, automobile, and sports industries due to their elevated strength to mass ratio, even though industries are facing lots of troubles in machining vicinity of these materials due to the existence of abrasive particles such as silicon carbide, aluminium oxide etc., which causes the brisk tool wear and hence tool malfunction within a very near to the ground machining time. In other hand Wire Electrical Discharge Machining (WEDM) may be a well alternative in the Machining of abrasive particle reinforced aluminium metal matrix composites over conventional machining. Also WEDM technology, convoluted cuts can be made through difficult-to-machine electrically conductive components with the high degree of accessible accuracy and the fine surface quality make WEDM priceless. Still, a threat occurred is the ceramic particles resists the current through the composites. Also the selection of Matrix material among the available materials is a tough criterion. Hence this paper focused on trim down these struggles. For this selecting the matrix material among the three series of aluminium materials available with the suppliers by means of the normalization criterion have been done. AMMC samples are produced as per the taguchi experimental design in view of collective material and WEDM parameters and machined to obtain the responses: surface roughness and kerf width. These are analyzed and derived an optimal set of parameters with the patronage of fuzzy approach.

Investigation of Surface Roughness, Kerf Width and MRR on AISI D2 Steel Machined by Wire EDM

Engineering industry has made tremendous growth in its manufacturing fields in the last decade but still the modern machines are not utilized up to the desired level. Wire electrical discharge machining (WEDM) is one such sophisticated machining process used in industry, which is a high-speed cutting and high-precision machining to realize productivity and improved accuracy for all manufacturing parts. Optimisation of the operating parameters of WEDM will result in efficiency with regard to higher surface finish and maximum material removal rate. The present investigation of the cutting performance on die steel with different parameters such as pulse on time, pulse off time, servo voltage, wire feed, current and cutting speed were involved to determine by which using wire electric discharge machining(WEDM) process. The shape of the wire and base material dimensions of brass wire 0.25mm diameter and AISI D2 steel with 100× 100 × 10 mm were carried out. The cutting performance outputs considered in this study are material removal rate (MRR), Kerf width and surface roughness (Ra). Experiments were carried out under Taguchi's L16 orthogonal array under different conditions of parameters. An optimal combination of WEDM parameters for proper machining of AISI D2 steel to achieve better surface roughness and Materials Removal Rate (MRR) is achieved in this investigation.

Single and multiobjective optimization of Inconel 718 nickel-based superalloy in the wire electrical discharge machining

Inconel 718 is widely used in high-temperature environments, high-performance aircraft, and hypersonic missile weapon systems; however, it is very difficult to machine using conventional techniques. This study employed an L9 Taguchi orthogonal array for the analysis of wire electrical discharge machining parameters when used for the machining of Inconel 718. Our aim was to determine the optimal combination of parameters to minimize surface roughness while maximizing the material removal rate. The Taguchi method is widely applied in mechanical engineering with the aim of identifying the optimal combination of processing parameters as they pertain to single quality characteristics. Unfortunately, Taguchi analysis often leads to contradictory results when seeking to rectify multiple objectives. To resolve this issue, this study implemented gray relational analysis in conjunction with Taguchi method to obtain the optimal combination of parameters to deal specifically with multiple quality objectives. For the dual objectives of surface roughness and material removal rate, the optimal combination of parameters derived using gray relational analysis resulted in a mean surface roughness of 2.75 μm. In L9 orthogonal array experiments, run 1 produced the best gray relational grade with mean surface roughness of 2.80 μm, representing an improvement of 1.8%. The material removal rate achieved after the application of gray relational analysis was 0.00190 g/s, whereas the L9 experiment achieved a material removal rate of 0.00123 g/s, representing an improvement of 54.5%.

Modeling of Process Parameters for Surface Roughness and Analysis of Machined Surface in WEDM of Al/SiC-MMC

Wire electric discharge machining (WEDM) is a newly emerging non-traditional technology for machining MMCs. In the present study, an attempt has been made to investigate the effect of WEDM parameters such as pulse on time, pulse off time, peak current, spark gap voltage, wire feed rate and wire tension on the surface roughness height (Ra) during WEDM of particulate silicon carbide aluminum metal matrix composites (Al/SiC-MMC). The RSM based Box–Behnken design is employed for experimental investigation. Utilized the acquired results, a quadratic regression model for surface roughness height (Ra) has been developed. An attempt has been made to optimize the process parameters for surface roughness height (Ra). To validate, confirmation experiments have been carried out and predicted results have been found to be in good agreement with experimental findings. The surface morphology of machined surfaces has also been studied using scanning electron microscope. Various surface defects and their possible reasons have been discussed.

Evaluation of the Influence of Wire Electrical Discharge Machining Parameters on Material Removal Rate and Surface Characteristics in Cutting of Inconel 825

Wire electrical discharge machining (WEDM) is a significant and broadly applicable non-conventional machining process due to its capability to produce parts with higher precision, accuracy and tolerance and complex profiles involving considerable surface characteristics. In this research, practical attempt has been made for cutting Inconel 825 material by WEDM process. Taguchi method and regression analysis have been adopted in order to optimize machining variables and developed equation to correlate the input variables and output variables. Input variables such as spark voltage, wire tension, flushing pressure and pulse on time have been taken for analysis and used orthogonal arrays to design experiments. Enumeration of output variables, material removal rate and surface roughness, has been carried out as they are of crucial importance in machining processes. The surface morphology of machined samples has also been examined by scanning electron microscopy (SEM).

Wire Rupture Optimization in Wire Electrical Discharge Machining using Taguchi Approach

Wire electrical discharge machining (WEDM) is one of the most important nontraditional machining process that is well-known for cutting difficult to machine materials. The wire electrode along with machining parameters control the WEDM process. This research work focuses on optimizing WEDM parameters using Taguchi technique to minimize wire rupture. Experiments have been done using the L18 orthogonal array. Each experiment is repeated three times to ensure accurate readings of the wire rupture. The statistical methods of signal to noise ratio (S/N ratio) is applied to study effects of peak current, pulse width, charging time, wire speed, and wire tension on wire rupture. As a results, the peak current, pulse width, and wire tension have the most significant effect on wire rupture followed by charging time and wire speed. The developed analysis can be used in the metal cutting field to identify the optimum machining parameters for less wire rupture.