Brass Wire Electrode Research Articles

Experimental Investigation and Optimization of Process Parameter for Inconel 718 Using Wire Electrical Discharge Machining

Inconel 718 is a nickel-based superalloy having high strength and low thermal conductivity. Due to its properties, wire electrical discharge machining has been selected. The paper reports an experimental investigation of Inconel 718 using zinc-coated brass wire electrode. Based on [Formula: see text], Box-Behnken design of response surface methodology has been adopted to estimate the effect of process parameter on the machining responses. Four controllable process parameters (viz., wire tension, wire speed, discharge current and pulse-on time) vary, each at three discrete levels, between parametric domains. The following machining responses, in terms of material removal rate (MRR), surface roughness ([Formula: see text]) and corner deviation ([Formula: see text]), have been investigated. Finally, an evolutionary computation method has been used based on non-dominated sorting genetic algorithm (NSGA-II) in order to find out the optimal set of solutions for rough-cutting. Experimental data have been used to develop regression models to optimize the process. The adequacy of the developed mathematical model has also been tested by the analysis of variance results. Pareto-optimal settings obtained through NSGA-II have been ranked by gray relation analysis to identify the best optimal set of solutions to avoid lengthiness and impreciseness in the judgment. Confirmation tests have been conducted for optimum machining parameter from the set of Pareto-optimal solutions for proving betterment.

EFFECT OF ELECTRODE MATERIAL ON CUT QUALITIES OF SHAPE MEMORY ALLOY DURING WEDM: A COMPARATIVE STUDY

This paper compares some of the vigorous machinability characteristics of SMA-Nitinol during WEDM process using uncoated and zinc coated brass wire electrodes. A series of experiments were regulated based on Taguchi’s L[Formula: see text] orthogonal array with an objective of unveiling the benefits of using coated brass wire electrodes in comparison to uncoated counterparts. Five factors, namely pulse-on time ([Formula: see text]), discharge current ([Formula: see text]), wire tension (WT), wire speed (WS) and flushing pressure (FP), were considered, each at three different levels to scrutinize four responses, viz. surface roughness (Ra), kerf width (KW), machining time (MT) and micro-hardness ([Formula: see text]h). It was perceived that zinc-coated brass wire was more preferable to get favorable responses like Ra, KW and [Formula: see text]h when compared with brass wire counterparts. FESEM micrographs also revealed that micro and large cracks, wide craters, recast layer were more prominent on the WEDMed surface of brass wire compared to zinc-coated brass wire. Use of zinc-coated brass wire electrode significantly improves the machinability of the selected work material within the specified range of process variables.

The effect of power supply current on recast layer in S45C steel using wire EDM

The purpose of this study is to determine the effect of the power supply current on recast layer on S45C steel cutting using wire EDM. In this research, the process of cutting workpieceused Mitsubishi Wire EDM Machine BA-8. Brass wire electrodes used Ø 0.2 mm and work piece material S45C 22 mm. The workpiece was cut into a circle to get 20 mm diameter with EDM wire machine with current power supply value of 4, 5, 6, 7, and 8 amperes. The results showed that the greater the power supply current used to produce thicker recast layer and the greater the hardness value was. The highest thickness value occurred at 8 Ampere power supply current variance of 35 μm. And the highest hardness value alsooccurred on the variation of 8 Ampere current power supply of 277.3 VHN.

Investigation on a novel surface microstructure wire electrode for improving machining efficiency and surface quality in WEDM

Wire electrode is one of the key factors in determining the machining performance of wire electrical discharge machining (WEDM), and developing high-performance wire electrode is an effective method for meeting the ever-increasing requirement of modern manufacturing industries. In this paper, a novel surface microstructure wire electrode (SMWE) is proposed to enhance the performance of WEDM. Experiment data demonstrate that, compared with brass wire electrode and zinc-coated wire electrode, SMWE increases machining efficiency by 23.9–77.8% for Inconel 718 and 14.8–38.6% for Ti6Al4V, and decreases surface roughness by 11–20% for Inconel 718 and 7–10% for Ti6Al4V, respectively. Besides, SMWE can also obtain smoother surface topography, thinner recast layer, and narrower surface cracks. Furthermore, the improvement mechanism of SMWE is revealed from different aspects. It can be found that SMWE can shorten discharge gap breaking downtime, avoid the occurrence of sparks at the same point, and promote more removed debris and heat energy to be brought out. In a word, this proposed SMWE has good popularization value for application in practical industries, and this study provides a new idea for developing high-performance wire electrode.

Modeling and reducing workpiece corner error due to wire deflection in WEDM rough corner-cutting

Workpiece accuracy is one of the key technology indexes in wire electrical discharge machining (WEDM), and workpiece corner error is an important form of workpiece geometric error. The goal of this paper is to model and reduce workpiece corner error due to wire deflection in WEDM rough corner-cutting using a novel surface microstructures wire electrode (SMWE) and cut-back method. Firstly, based on string vibration theory, a wire deflection model is presented to reveal the forming mechanism of workpiece corner error during rough corner-cutting, and the theoretical solution of corner error due to wire deflection is derived out. Secondly, a set of single factor experiment is implemented to analyze the improvement effect of SMWE on the corner error. Experiment data indicates that the proposed SMWE can decrease workpiece corner error by 5.53–27.15% comparing with brass wire electrode (BWE) in rough corner-cutting. Besides, the influences of process parameters on corner error are also investigated. Additionally, through the inverse method, the discharge resultant force acting on wire electrode is acquired, and the calculated data of corner error shows good agreement with experiment data in verified experiment. Finally, on the basis of wire deflection model, the cut-back method (CBM) is proposed to compensate wire electrode path, and it is proved that this method can reduce workpiece corner error by about 87% in rough corner-cutting.

Influence of process parameters on MRR, kerf width and surface roughness during WEDM on Inconel 718: performance analysis of electrode tool material

In the present study, an attempt has been made to study the performance of (brass wire electrode and zinc coated brass wire electrode) wire electrodes in relation to material removal rate (MRR), kerf width and surface roughness of machined Inconel 718 obtained by wire electro discharge machining (WEDM) process. Experiments have been conducted using L16 orthogonal array with two different types of wire electrodes and by tuning following controllable process parameters; discharge current, flushing pressure, wire tension, and pulse-on time. It has been observed that zinc coated brass wire produces lesser kerf width as well as surface roughness; higher MRR as compared to brass wire electrode. The pulse-on time is found to be the most significant factor on influencing MRR for all electrodes types. Pulse-on time and discharge current is found to be very significant on affecting kerf width for all electrodes types finally, Grey-Taguchi relational analysis have been adopted to establish the optimal parametric combination for both the wire electrode.

Influence of process parameters on MRR, kerf width and surface roughness during WEDM on Inconel 718: performance analysis of electrode tool material

In the present study, an attempt has been made to study the performance of (brass wire electrode and zinc coated brass wire electrode) wire electrodes in relation to material removal rate (MRR), kerf width and surface roughness of machined Inconel 718 obtained by wire electro discharge machining (WEDM) process. Experiments have been conducted using L16 orthogonal array with two different types of wire electrodes and by tuning following controllable process parameters; discharge current, flushing pressure, wire tension, and pulse-on time. It has been observed that zinc coated brass wire produces lesser kerf width as well as surface roughness; higher MRR as compared to brass wire electrode. The pulse-on time is found to be the most significant factor on influencing MRR for all electrodes types. Pulse-on time and discharge current is found to be very significant on affecting kerf width for all electrodes types finally, Grey-Taguchi relational analysis have been adopted to establish the optimal parametric combination for both the wire electrode.

Utility approach for multi target streamlining of process parameters in wire EDM

This paper depicts the improvement of multireaction enhancement system utilizing utility technique to foresee and select the ideal setting of machining parameters in wire electro-release machining (WEDM) process. Investigations were arranged utilizing Taguchi's L27 orthogonal exhibit. A wide range of Wire EDM control variables such as pulse on time duration, pulse off time duration, servo voltage along with wire feed rate were judged for investigation. Multi reaction enhancement was performed for both cutting pace (CS) and surface unpleasantness (SR) utilizing utility idea to discover the ideal procedure parameter setting. The level of essentialness of the machining parameters for their impact on the CS and SR were controlled by utilizing investigation of fluctuation (ANOVA). In present study utility approach method used to optimize the process parameter in wire EDM of magnesium Al6061/SiC/Graphite hybrid composite with zinc covered brass wire electrode. The approach depicted here is relied upon to be profoundly useful to assembling enterprises, and furthermore different territories, for example, aviation, car and apparatus making businesses. The parameters corresponding to experiment run number 7 are pulse on time 108 units (Level 1), pulse off time 60 units (Level 3), peak current 230 units (Level 3), gap set voltage 60 units (Level 3), wire feed 3 units (Level 1) and wire tension 4 units (Level 1) are the best combination to achieve better surface roughness and cutting speed.

Assessment of material removal capability with vibration-assisted wire electrical discharge machining

Titanium alloys are prevalently used in automotive, aerospace and biomedical applications. It is identified as not easy to machine by conventional machining process because of fast tool wear. Hence, for machining of titanium alloy, non-conventional machining processes are generally recommended. In non-conventional machining, vibration assisted Wire Electrical Discharge Machining has shown promising results to improve the machining rate. The present work will focus on machining of titanium alloy workpiece by vibrating the wire in lateral direction with varied frequency of excitation to enhance the material removal rate and to obtain the required kerf width in Wire Electrical Discharge Machining. Experiments were performed on Ti-6Al-4V alloy material during a wire electrical discharging machine operation using zinc coated brass wire and brass wire electrode. Roughness with all those irregularities on machined surface, with varied vibration condition, are measured with contact stylus type surface roughness measuring instrument. Machined kerf size was measured using non-contact optical Co-ordinate Measuring Machine. White layer formed and surface integrity were examined through Scanning Electron Microscope with provision of Energy Dispersive Spectroscopy. The developed vibrating system worked effectively, improved material removal rate and their surface modification has been obtained and reported.

Experimental investigation and modelling of WEDM process for machining nano-structured hardfacing material

In recent years, nano-structured hardfacing alloy constituting fine carbides, borides and boro-carbides have become pioneered in modern manufacturing industries due to their superior properties (excellent hardness, toughness and wear resistance) even at elevated temperatures. A nano-structured hardfacing alloy component was produced using manual metal arc welding process for making turning tool insert. The present paper investigates the effect of wire electrical discharge machining (WEDM) parameters such as discharge pulse time, discharge stop time, servo voltage, wire tension and wire feed rate on machining performances viz. material removal rate, machining time and surface roughness after proof-machining of welded nano-structured hardfacing material. Taguchi’s (L25) orthogonal array has been used to perform the experimental runs using conventional brass wire and zinc-coated wire electrodes, respectively. A combination of Taguchi’s robust design concept with principal component analysis has been applied to optimize the process parameters. For brass wire, the optimal settings of the input process parameters corresponds to discharge pulse time 0.45 µs, discharge stop time 8 µs, servo voltage 35 V, wire tension 800 g and wire feed rate 7 m/min, respectively. Similarly, for zinc-coated brass wire, the corresponding settings are discharge pulse time 0.5 µs, discharge stop time 11 µs, servo voltage 41 V, wire tension 600 g and wire feed rate 7 m/min. This paper also establishes the inter-relationships of various WEDM machining parameters and performances by employing response surface methodology-based approach. A confirmation test has also been carried out with the optimal process parameters to conform to the experimental result.

Properties Evaluation of Thin Microhardened Surface Layer of Tool Steel after Wire EDM

This paper describes results of experimental research on the thin microhardened surface layer of a machined surface that occurs in materials using wire electrical discharge machining (WEDM) with brass wire electrode. The direct influence of microhardened surface layer on resulting machined surface quality of tool steel EN X210Cr12 (W.-Nr. 1.2080) was examined. The aim of the experiment was to contribute to the knowledge of mutual interactions between main WEDM technological parameters, the influence of these parameters on the total affected depth, and on the variation of microhardness of sub-surface layers of machined surface. Based on the microhardness experimental measurements, mathematical models were established by the Least Square Method (LSM) in order to simulate and predict final quality of machined surface after WEDM. Recommendations are given for setting the main technological parameters of the discharge process concerning minimization of total microhardened surface layer depth and microhardened surface layer homogeneity along the whole cross-section profile of the machined surface.

Influence of process parameters on material removal rate and surface roughness in WED-machining of Ti<SUB align="right">50Ni<SUB align="right">40Cu<SUB align="right">10 shape memory alloy

Among the shape memory alloys (SMAs), TiNi SMAs have been typically used as the functional elements in the larger part of the industries due to exceptional properties like super elasticity and shape memory effect. However, traditional machining of these alloys is fairly complex due to these properties. The non-traditional machining process like electric discharge machining (EDM) exhibits outstanding capability in machining of these alloys. The poor selection of machining parameters may cause increased roughness of workpiece and lesser material removal rate. Hence, an effort has been made in the present work to explore the effects of three process parameters, such as pulse on time, pulse off time and servo voltage in wire electric discharge machining (WEDM) of Ti50Ni40Cu10 shape memory alloy (SMA) using zinc coated brass wire electrode on material removal rate and surface roughness using response surface methodology (RSM)-based mathematical models. The experiments were planned as per central composite design (CCD). The investigations revealed that pulse on time and servo voltage have predominant effects in maximising material removal rate and minimising surface roughness. The best combination of the process parameters for multi-response optimisation was obtained through desirability function.

Effect of adding SiC powder on surface quality of quartz glass microslit machined by WECDM

Quartz, being hard and brittle, is difficult to machine. Although good machining effects of quartz have been achieved by wire electrochemical discharge machining (WECDM), the surface quality of microslits obtained needs to be enhanced and higher machining precision is desired. To attain improvement in quartz machining, this study performs WECDM under titrated electrolyte flow with the addition of silicon carbide (SiC) powder. On the one hand, titrated electrolyte can facilitate rapid replenishment of the electrolyte, which contributes to maintain the stability of the insulating gas film, thus ensuring frequent and steady electrical discharge for better machining precision. On the other hand, the SiC powder added can help polish the finished workpiece for surface quality enhancement. Experiments are conducted to determine the appropriate machining parameters and to explore the processing mechanisms involved. Comparison in terms of machining precision and surface quality is made for WECDM conducted with and without additives. Experimental results show that better surface roughness and precision of microslits can be obtained with brass wire electrodes of 150 μm diameter and SiC powder of 11 μm at 5 wt%. The addition of abrasive SiC powder helped decrease surface roughness from 1.13 to 0.22 μm, an improvement in surface quality by 80 %. Moreover, the mean slit width was also reduced from 200 to 185 μm. Hence, WECDM of quartz glass under titrated electrolyte with SiC powder added to the electrolyte can indeed enhance surface quality and precision of the microslit. Moreover, not only does such approach use less electrolyte, but also it incurs lower cost and less pollution, making it cost effective and environmental friendly.

Review of improvements in wire electrode properties for longer working time and utilization in wire EDM machining

Wire electrical discharge machining (WEDM) is an important technology, which demands high-speed cutting and high-precision machining to realize productivity and improved accuracy for manufacturing hard materials. WEDM has experienced explosive growth and complexity of equipment as well as rising demand for the basic process tool (the wire electrode). Greater taper angles, thicker workpieces, automatic wire threading, and long periods of unattended operation make the selection of the ideal wire a much more critical basis for achieving successful operation. This paper focuses on the evolution of EDM wire electrode technologies from using copper to the widely employed brass wire electrodes and from brass wire electrodes to the latest coated wire electrodes. Wire electrodes have been developed to help user demand and needs through maximum productivity and quantity by choosing the best wire. In the final part of the paper, the possible trends for future WEDM electrode research are discussed.

Experimental Study and Optimization of Wire-Electrical Discharge Machined WC-15%Co Metal Matrix Composites

Wire Electrical discharge Machining plays an important role in the field of hard, difficult to machine materials like metal matrix composites. Machining process must keep pace with material development. For electrically conductive materials wire electro discharge machining is a viable option due to high accuracy, precision, and ability to achieve complex, intricate shaped profiles on even thin works. Due to thermo-electric nature it is a stochastic process in nature. To simplify the difficulty in determining parameters for the improvement of cutting performance and optimization, analysis of variance and regression analysis were made use of. Tungsten carbide cobalt metal matrix composites finds increasing applications in conventional application like tools and dies as well as in developing fields like bio-medical instruments and aero-space industries. In this present work, the problem of parameter selection, optimization for wire electro discharge machining on tungsten carbide-15% cobalt metal matrix composites, a less worked composition has been undertaken. Sodick AQ-427L wire-edm machine was used with a 0.25 diameter zinc coated brass wire electrode, to cut the material. Each experiment done under different cutting conditions of inputs like pulse on time, pulse off time, wire speed and peak current and repeated for three observations and the average was selected. Optimum machining parameter combination for material removal rate was obtained by using the desirability response optimizer function. Analysis of variance, Confirmation experiment was carried and good improvements were obtained.

Taguchi Method Implementation in Taper Motion Wire EDM Process Optimization

Wire electrical discharge machining (Wire EDM) is a non-conventional metal removal process as well as one of the best manufacturing processes suitable for producing jigs, fixtures, and dies. Among others, the machine is able to cut a workpiece having oblique and taper form. The objective of this paper is to optimize the input parameters of Wire EDM machine, such as no load voltage, capacitor, on-time, off-time, and servo voltage, for machining medium carbon steel ASSAB 760. The Taguchi design of experiments, the signal-to-noise ratio, and analysis of variance are employed to analyze the effects of the input parameters by adopting L18 Taguchi orthogonal array (OA) to conduct experiments using brass wire electrode of 0.2 mm in diameter. In order to achieve the maximum material removal rate (MRR) or the minimum surface roughness (SR), six controllable factors, i.e., the parameters of each at three levels are applied for determining the optimal combination of factors and levels. The results reveal that the MRR and the SR are greatly influenced by the on-time and the taper angle, respectively. Experimental results affirm the effectiveness of the method, and also prove that the Taguchi method is suitable to solving the stated problem within minimum number of experiments as compared to that of a full factorial design.

Selection of Wire Electrical Discharge Machining Process Parameters on Stainless Steel AISI Grade-304 using Design of Experiments Approach

Wire electrical discharge machining (WEDM) is a specialized thermal machining process capable of accurately machining parts of hard materials with complex shapes. Parts having sharp edges that pose difficulties to be machined by the main stream machining processes can be easily machined by WEDM process. Design of Experiments approach (DOE) has been reported in this work for stainless steel AISI grade-304 which is used in cryogenic vessels, evaporators, hospital surgical equipment, marine equipment, fasteners, nuclear vessels, feed water tubing, valves, refrigeration equipment, etc., is machined by WEDM with brass wire electrode. The DOE method is used to formulate the experimental layout, to analyze the effect of each parameter on the machining characteristics, and to predict the optimal choice for each WEDM parameter such as voltage, pulse ON, pulse OFF and wire feed. It is found that these parameters have a significant influence on machining characteristic such as metal removal rate (MRR), kerf width and surface roughness (SR). The analysis of the DOE reveals that, in general the pulse ON time significantly affects the kerf width and the wire feed rate affects SR, while, the input voltage mainly affects the MRR.

Effect of cryogenic treated brass wire electrode on material removal rate in wire electrical discharge machining

In this article, the effect of cryogenic treatment on the brass wire electrode used in wire electrical discharge machining is investigated. Deep cryogenic (−184°C) treatment is given to the brass wire electrode. The microstructure and crystalline phase of deep and non-cryogenic treated brass wire electrodes is observed by scanning electron microscope and X-Ray diffraction. The experimental results show that the structure is more refined in deep cryogenic treatment as compared to non-cryogenic treatment. The electrical conductivity of deep electrode is greatly improved. The effect of deep cryogenic treatment on the brass wire electrode is also investigated for the performance of wire electrical discharge machining. Taguchi experimental design has been applied to investigate the optimal parameters for maximum material removal rate. The ANOVA analysis indicates that type of wire, pulse width, time between two pulses and wire tension are significant factors for maximization of material removal rate. The cryogenic treatment results in improved material removal rate.

Effect of shallow cryogenic treated brass wire electrode on workpiece surface roughness in wire-EDM

In this paper, the effect of shallow cryogenic treated (–110°C) brass wire electrodes on workpiece (EN-31) surface roughness (SR) in wire electrical discharge machining (wire-EDM) is investigated. Five process parameters, namely type of wire, pulse width, time between two pulses, wire tension and servo reference mean voltage have been considered. The outcome of the investigation will identify the significant parameters and their effect on SR with shallow cryogenic treated and untreated wire electrode. The study indicated that all the selected parameters except wire tension and servo reference mean voltage have a significant effect on the means and S/N ratio (of analysis of variance) for SR. Taguchi experimental design has been applied to investigate the optimal parameters for minimisation of SR. The analysis of variance (ANOVA) analysis indicates that the shallow cryogenic treated wire reduces the SR. The results of confirmation experiments for SR showed that the setting of pulse width at low level (0.4 μs), time between two pulses at high level (16 μs) and selecting shallow cryogenic treated wire, produced optimal surface roughness (SR) from EN-31 material surface.

The effect of machining parameters on surface roughness and material removal rate with cryogenic treated wire in WEDM

Wire electrical discharge machining (WEDM) has been used widely for the manufacturing of dies, moulds, punches and machine parts. The machining performance is affected by process parameters and type of wire electrode used. Increased cutting speed and improved accuracy can be realised in terms of high performance wire electrodes. The purpose of this study is to investigate the effect of cryogenic treated brass wire electrode on surface roughness and material removal rate for WEDM. This paper describes the influence of various machining parameters (including pulse width, time between two pulses, wire tension and wire feed) on surface roughness and material removal rate by using one variable at a time approach. Improvement in surface roughness was observed for lower values of pulse width and higher values of time between two pulses. Under same conditions, deep and shallow cryogenic treated wire electrodes shows significant improvement in machining rate over untreated wire electrodes.