Empirical Modeling of High-Speed WEDM Finishing in Gas

2012 ◽  
Vol 486 ◽  
pp. 503-508 ◽  
Author(s):  
Yu Mei Lu ◽  
Tong Wang ◽  
Chao Qun Wang ◽  
Cheng Wen Wang
Keyword(s):  
Regression Model ◽  
High Speed ◽  
High Reliability ◽  
Cutting Speed ◽  
Process Models ◽  
Empirical Modeling ◽  
Pulse Interval ◽  
Five Factors ◽  
Pulse On Time ◽  
Wedm Process

This paper aims at getting the finishing process models in HS-WEDM in gas. Using cutting speed and the roughnessRaas index, the five factors of pulse-on time, peak current, offset, pulse interval ratio and worktable feed were chosen in dry finishing. The effects of the five factors and their interaction on cutting speed and the Surface roughnessRaand empirical models for cutting speed and roughnessRawere developed by performing a designed experiment based on the central composite design (CCD) experiments, significant order influencing cutting speed and roughness were found. The results of the verification test show thatRaRegression Model and Cutting Speed Regression Model have high reliability, and can achieve significant prediction effect, more accurate mathematical models are provided for the further HS-WEDM process research.

Experimental Study on High-Speed WEDM Finishing in Gas Based on Central Composite Design

2013 ◽  
Vol 662 ◽  
pp. 319-322
Author(s):  
Tong Wang ◽  
Yu Mei Lu ◽  
Chao Qun Wang ◽  
Kun Jiang ◽  
Fei Xie ◽  
...  
Keyword(s):  
Regression Model ◽  
Central Composite Design ◽  
Pulse Duration ◽  
High Speed ◽  
High Reliability ◽  
Cutting Speed ◽  
Pulse Interval ◽  
Five Factors ◽  
Verification Test ◽  
Central Composite

Using cutting speed and the roughness as index, the five factors as pulse duration, peak current, offset, ratio of pulse interval to pulse duration and worktable feed were chosen in dry finishing. Based on the single factor experiment, the central composite design (CCD) method is used to study the effects of the five factors and their interactions on cutting speed and the surface roughness and develop empirical models for cutting speed and roughness Ra. Significant order influencing cutting speed and roughness are found. The results of the verification test show that Ra regression model and cutting speed regression model have high reliability, and can achieve significant prediction effect.

scholarly journals Empirical Modeling of Average Cutting Speed during WEDM of Hastelloy C22

2018 ◽  
Vol 249 ◽  
pp. 02003 ◽  
Author(s):  
Bhupinder Singh ◽  
Joy Prakash Misra
Keyword(s):  
Process Parameters ◽  
Cutting Speed ◽  
Performance Measure ◽  
Empirical Modeling ◽  
Workpiece Material ◽  
Peak Current ◽  
The Right ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Wedm Process

Cutting speed (CS) is a key performance measure to achieve optimal utilization of the WEDM process. However, input process parameters of WEDM and combination of wire and workpiece material greatly hamper CS and hence productivity and machining efficiency. Therefore, it is essential to pick the right combination of parameters and wire and workpiece material to obtain better CS. In this paper, four process parameters: Pulse-on time, Pulse-off time, Spark-gap voltage, and Peak current were chosen to develop an empirical model for CS during WEDM of Hastelloy C22 to provide a guideline to the potential users of the technique. This paper describes the response surface methodology (RSM) based mathematical modeling for average cutting speed. Furthermore, analysis of variance (ANOVA) was applied to find out significant process parameters and it was depicted that pulse on time and peak current were the major parameters affecting CS.

scholarly journals Empirical Modeling of Average Cutting Speed during WEDM of Gas Turbine Alloy

2018 ◽  
Vol 221 ◽  
pp. 01002 ◽  
Author(s):  
Bhupinder Singh ◽  
Joy Prakash Misra
Keyword(s):  
Process Parameters ◽  
Energy Levels ◽  
Cutting Speed ◽  
Performance Measure ◽  
Empirical Modeling ◽  
Workpiece Material ◽  
The Right ◽  
Spherical Droplets ◽  
Pulse On Time ◽  
Wedm Process

Cutting speed (CS) is a key performance measure to achieve optimal utilization of the WEDM process. However, input process parameters of WEDM and combination of wire and workpiece material greatly hamper CS and hence productivity and machining efficiency. Therefore, it is essential to pick the right combination of parameters and wire and workpiece material to obtain better CS. In this paper, four process parameters: Ton, Toff, Sv, and Ip were chosen to develop an empirical model for CS during WEDM of nimonic 263 to provide a guideline to the potential users of the technique. This paper describes the response surface methodology (RSM) based mathematical modeling for average cutting speed. Furthermore, analysis of variance (ANOVA) was applied to find out significant process parameters and it was depicted that pulse on time and peak current were the major parameters affecting CS. In addition, WEDMed surfaces were analysed through FE-SEM at various discharge energy levels. The WEDMed surfaces appeared in the form of micro-cracks, craters, spherical droplets and the lump of debris. It is obvious from the current investigation that input parameters have the significant influence on cutting speed. The key features of experimental procedure are also highlighted in this paper.

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

2019 ◽  
Vol 27 (04) ◽  
pp. 1950136
Author(s):  
HIMADRI MAJUMDER ◽  
KALIPADA MAITY
Keyword(s):  
Micro Hardness ◽  
Process Variables ◽  
Machining Time ◽  
Five Factors ◽  
Series Of Experiments ◽  
Pulse On Time ◽  
Wedm Process ◽  
Different Levels ◽  
Fesem Micrographs ◽  
Brass Wire

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.

scholarly journals Integration of Fuzzy AHP and Fuzzy TOPSIS Methods for Wire Electric Discharge Machining of Titanium (Ti6Al4V) Alloy Using RSM

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7408
Author(s):  
Kishan Fuse ◽  
Arrown Dalsaniya ◽  
Dhananj Modi ◽  
Jay Vora ◽  
Danil Yurievich Pimenov ◽  
...  
Keyword(s):  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Fuzzy Ahp ◽  
Cutting Speed ◽  
High Hardness ◽  
Fuzzy Topsis ◽  
Ti6al4v Alloy ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Wedm Process

Titanium and its alloys exhibit numerous uses in aerospace, automobile, biomedical and marine industries because of their enhanced mechanical properties. However, the machinability of titanium alloys can be cumbersome due to their lower density, high hardness, low thermal conductivity, and low elastic modulus. The wire electrical discharge machining (WEDM) process is an effective choice for machining titanium and its alloys due to its unique machining characteristics. The present work proposes multi-objective optimization of WEDM on Ti6Al4V alloy using a fuzzy integrated multi-criteria decision-making (MCDM) approach. The use of MCDM has become an active area of research due to its proven ability to solve complex problems. The novelty of the present work is to use integrated fuzzy analytic hierarchy process (AHP) and fuzzy technique for order preference by similarity to ideal situation (TOPSIS) to optimize the WEDM process. The experiments were systematically conducted adapting the face-centered central composite design approach of response surface methodology. Three independent factors—pulse-on time (Ton), pulse-off time (Toff), and current—were chosen, each having three levels to monitor the process response in terms of cutting speed (VC), material removal rate (MRR), and surface roughness (SR). To assess the relevance and significance of the models, an analysis of variance was carried out. The optimal process parameters after integrating fuzzy AHP coupled with fuzzy TOPSIS approach found were Ton = 40 µs, Toff = 15 µs, and current = 2A.

Application of Uniform Design in Experiments of WEDM in Gas

2012 ◽  
Vol 426 ◽  
pp. 11-14 ◽  
Author(s):  
Tong Wang ◽  
Shu Qiang Xie ◽  
Xiao Cun Xu ◽  
Q. Chen ◽  
X.C. Lü ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
Removal Rate ◽  
Uniform Design ◽  
Cutting Speed ◽  
Pulse Interval ◽  
Machining Parameters ◽  
Regression Equations ◽  
Interval Ratio ◽  
Parameter Values

Comparing with conventional WEDM in emulsion, dry finishing of high-speed WEDM (HS-WEDM) has advantages such as higher material removal rate, better surface roughness and straightness. Authors have presented a new procedure as gas-liquid combined multiple cut, in which roughing is processed in dielectric liquid, and semi-finishing is in liquid or gas, while finishing is in gas. For better understanding the effect of machining parameters on surface roughness(Ra) and cutting speed (Vw) in dry finishing, a L25(56) Design test was implemented. The analysis of variance shows that offset and wire length are not significant on Ra and Vw. In this paper, the other four significant parameters, such as pulse duration, pulse interval ratio, peak current and no load worktable feed, were selected as factors in Uniform Design test. The final regression equations for Ra and Vw in terms of the actual parameter values were calculated out with MATLAB. Regression statistics of values R2 imply the two regression equtions fit well with test data and Model F-Values imply the two models are significant. Values t and α for regression equation coefficient tests of Ra and Vw show the major impacting items and interactions between them.

Performance Analysis on Eco-friendly Machining of Ti6Al4V using Powder Mixed with Different Dielectrics in WEDM

2020 ◽  
Vol 17 (3) ◽  
pp. 8128-8139
Author(s):  
S. Chakraborty ◽  
S. Mitra ◽  
D. Bose
Keyword(s):  
Metal Removal ◽  
Removal Rate ◽  
Machining Process ◽  
Process Efficiency ◽  
Machining Parameters ◽  
Dielectric Fluids ◽  
High Emission ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Wedm Process

The recent scenario of modern manufacturing is tremendously improved in the sense of precision machining and abstaining from environmental pollution and hazard issues. In the present work, Ti6Al4V is machined through wire EDM (WEDM) process with powder mixed dielectric and analyzed the influence of input parameters and inherent hazard issues. WEDM has different parameters such as peak current, pulse on time, pulse off time, gap voltage, wire speed, wire tension and so on, as well as dielectrics with powder mixed. These are playing an essential role in WEDM performances to improve the process efficiency by developing the surface texture, microhardness, and metal removal rate. Even though the parameter’s influencing, the study of environmental effect in the WEDM process is very essential during the machining process due to the high emission of toxic vapour by the high discharge energy. In the present study, three different dielectric fluids were used, including deionised water, kerosene, and surfactant added deionised water and analysed the data by taking one factor at a time (OFAT) approach. From this study, it is established that dielectric types and powder significantly improve performances with proper set of machining parameters and find out the risk factor associated with the PMWEDM process.

Effect of Powder-Mixed Dielectric on EDM Process Performance

2020 ◽  
Vol 38 (8A) ◽  
pp. 1226-1235
Author(s):  
Safa R. Fadhil ◽  
Shukry. H. Aghdeab
Keyword(s):  
Silicon Carbide ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
High Speed Steel ◽  
Transformer Oil ◽  
Dielectric Fluid ◽  
Peak Current ◽  
Powder Concentration ◽  
Pulse On Time

Electrical Discharge Machining (EDM) is extensively used to manufacture different conductive materials, including difficult to machine materials with intricate profiles. Powder Mixed Electro-Discharge Machining (PMEDM) is a modern innovation in promoting the capabilities of conventional EDM. In this process, suitable materials in fine powder form are mixed in the dielectric fluid. An equal percentage of graphite and silicon carbide powders have been mixed together with the transformer oil and used as the dielectric media in this work. The aim of this study is to investigate the effect of some process parameters such as peak current, pulse-on time, and powder concentration of machining High-speed steel (HSS)/(M2) on the material removal rate (MRR), tool wear rate (TWR) and the surface roughness (Ra). Experiments have been designed and analyzed using Response Surface Methodology (RSM) approach by adopting a face-centered central composite design (FCCD). It is found that added graphite-silicon carbide mixing powder to the dielectric fluid enhanced the MRR and Ra as well as reduced the TWR at various conditions. Maximum MRR was (0.492 g/min) obtained at a peak current of (24 A), pulse on (100 µs), and powder concentration (10 g/l), minimum TWR was (0.00126 g/min) at (10 A, 100 µs, and 10 g/l), and better Ra was (3.51 µm) at (10 A, 50 µs, and 10 g/l).

Enhancement of EDM Performance by Using Copper-Silver Composite Electrode

2020 ◽  
Vol 38 (9A) ◽  
pp. 1352-1358
Author(s):  
Saad K. Shather ◽  
Abbas A. Ibrahim ◽  
Zainab H. Mohsein ◽  
Omar H. Hassoon
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
High Speed ◽  
Composite Electrode ◽  
Removal Rate ◽  
Pure Copper ◽  
High Speed Steel ◽  
Pulse On Time ◽  
Pulse Off Time

Discharge Machining is a non-traditional machining technique and usually applied for hard metals and complex shapes that difficult to machining in the traditional cutting process. This process depends on different parameters that can affect the material removal rate and surface roughness. The electrode material is one of the important parameters in Electro –Discharge Machining (EDM). In this paper, the experimental work carried out by using a composite material electrode and the workpiece material from a high-speed steel plate. The cutting conditions: current (10 Amps, 12 Amps, 14 Amps), pulse on time (100 µs, 150 µs, 200 µs), pulse off time 25 µs, casting technique has been carried out to prepare the composite electrodes copper-sliver. The experimental results showed that Copper-Sliver (weight ratio70:30) gives better results than commonly electrode copper, Material Removal Rate (MRR) Copper-Sliver composite electrode reach to 0.225 gm/min higher than the pure Copper electrode. The lower value of the tool wear rate achieved with the composite electrode is 0.0001 gm/min. The surface roughness of the workpiece improved with a composite electrode compared with the pure electrode.

Effects of Cooling Conditions on Thermal Crack Initiation of Brittle Cutting Tools during Intermittent Cutting

2015 ◽  
Vol 656-657 ◽  
pp. 237-242
Author(s):  
Kenji Yamaguchi ◽  
Tsuyoshi Fujita ◽  
Yasuo Kondo ◽  
Satoshi Sakamoto ◽  
Mitsugu Yamaguchi ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Thermal Shock ◽  
High Speed ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Condition ◽  
Thermal Crack ◽  
Cooling Conditions ◽  
Cutting Operation ◽  
Intermittent Cutting

It is well known that a series of cracks running perpendicular to the cutting edge are sometimes formed on the rake face of brittle cutting tools during intermittent cutting. The cutting tool is exposed to elevated temperatures during the periods of cutting and is cooled quickly during noncutting times. It has been suggested that repeated thermal shocks to the tool during intermittent cutting generate thermal fatigue and result in the observed thermal cracks. Recently, a high speed machining technique has attracted attention. The tool temperature during the period of cutting corresponds to the cutting speed. In addition, the cooling and lubricating conditions affect the tool temperature during noncutting times. The thermal shock applied to the tool increases with increasing cutting speed and cooling conditions. Therefore, to achieve high-speed cutting, the evaluation of the thermal shock and thermal crack resistance of the cutting tool is important. In this study, as a basis for improving the thermal shock resistance of brittle cutting tools during high-speed intermittent cutting from the viewpoint of cutting conditions, we focused on the cooling conditions of the cutting operation. An experimental study was conducted to examine the effects of noncutting time on thermal crack initiation. Thermal crack initiation was found to be restrained by reducing the noncutting time. In the turning experiments, when the noncutting time was less than 10 ms, thermal crack initiation was remarkably decreased even for a cutting speed of 500 m/min. In the milling operation, the number of cutting cycles before thermal crack initiation decreased with increasing cutting speed under conditions where the cutting speed was less than 500 m/min. However, when the cutting speed was greater than 600 m/min, thermal crack initiation was restrained. We applied the minimal quantity lubrication (MQL) coolant supply to the intermittent cutting operation. The experimental results showed that the MQL diminished tool wear compared with that under the dry cutting condition and inhibited thermal crack initiation compared with that under the wet cutting condition.

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