scholarly journals The Influence of WEDM Parameters Setup on the Occurrence of Defects When Machining Hardox 400 Steel

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3758 ◽  
Author(s):  
Katerina Mouralova ◽  
Tomas Prokes ◽  
Libor Benes ◽  
Josef Bednar
Keyword(s):  
Electrical Discharge Machining ◽  
Subsurface Layer ◽  
Cutting Speed ◽  
Electrically Conductive ◽  
Subsequent Determination ◽  
Time Gap ◽  
Almost All ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
The Given

The unconventional technology wire electrical discharge machining is a highly used technology for producing precise and indented shaped parts of all materials that are at least electrically conductive. Its wide use makes this technology applicable in almost all branches of industry, even in the automotive industry, where the abrasion resistant material under investigation Hardox 400 steel is widely used for the manufacturing of truck bodies. The aim of this study was a comprehensive analysis of the machinability of this material using WEDM employing a 33−round experiment. Based on the change in machine parameters (pulse off time, gap voltage, discharge current, pulse on time, and wire feed), the cutting speed, the topography of machined surfaces, and the chemical composition of the workpiece surface, the morphology and condition of the subsurface layer including lamella production and a subsequent determination of the distribution of individual elements in the given area were analyzed. It has been found that during the machining of this steel, many defects occur in the subsurface layer of the material in the form of cracks with a depth of up to 22 µm and burned cavities. However, by appropriately adjusting the machine parameters, it was possible to completely remove these cracks.

Multicut technology used in WEDM machining of Mar-M247

2021 ◽  
pp. 095440542110434
Author(s):  
Katerina Mouralova ◽  
Ales Polzer ◽  
Libor Benes ◽  
Josef Bednar ◽  
Radim Zahradnicek ◽  
...  
Keyword(s):  
Electrical Discharge Machining ◽  
Subsurface Layer ◽  
Cutting Speed ◽  
Complete Removal ◽  
Nickel Superalloy ◽  
Machined Surface ◽  
The Third ◽  
Optimal Setting ◽  
Pulse On Time ◽  
Pulse Off Time

Wire electrical discharge machining (WEDM) technology is often used for the final machining of parts to the required surface quality without further finishing operations. At the same time, WEDM has a significant advantage over other machining technologies, and in the fact, it is possible to machine all materials, regardless of their hardness or toughness, it only needs to be at least electrically conductive. Aviation nickel superalloy Mar-M247, which is usually machined to the final form by parts using WEDM, was the subject of research in this study. In order to find the optimal setting of machine parameters (Pulse on time, Pulse off time, and Discharge current) for multicut machining, an extensive design of experiment was performed with a total of 54 circles, which optimized the cutting speed in the first and second cuts and the topography of the machined surface was taken into account in the third cut. Subsequently, an analysis of the topography and morphology of the machined samples was performed, including an analysis of the condition of the subsurface layer. The study also included the analysis of the lamella in a transmission electron microscope. It was found that with the maximization of the cutting speed in the third cut, the surface topography deteriorates proportionally, but it also leads to the complete removal of all cracks formed in the first cut.

scholarly journals Analysis of the Machinability of Copper Alloy Ampcoloy by WEDM

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 893 ◽  
Author(s):  
Katerina Mouralova ◽  
Libor Benes ◽  
Tomas Prokes ◽  
Josef Bednar ◽  
Radim Zahradnicek ◽  
...  
Keyword(s):  
Copper Alloy ◽  
Electrical Discharge Machining ◽  
Subsurface Layer ◽  
Cutting Speed ◽  
Response Monitoring ◽  
Composition Analysis ◽  
Cross Sectional ◽  
Optimal Setting ◽  
Pulse On Time ◽  
Pulse Off Time

The unconventional technology of wire electrical discharge machining is widely used in all areas of industry. For this reason, there is always an effort for efficient machining at the lowest possible cost. For this purpose, the following comprehensive study has been carried out to optimize the machining of the copper alloy Ampcoloy 35, which is particularly useful in plastic injection moulds. Within the study, a half-factor experiment of 25-1 with 10 axial points and seven central points of a total of 33 rounds was carried out, which was focused on the response monitoring of the input factors in the form of the machine parameters setup: gap voltage, pulse on time, pulse off time, discharge current, and wire speed. Based on the study of the response in the form of cutting speed and surface topography, their statistical models were created, while the optimal setting of machine parameters was determined to maximize the cutting speed and minimize the topography parameters. Further, a detailed cross-sectional analysis of surface and subsurface layer morphology was performed using electron microscopy including chemical composition analysis. In order to study microstructural changes in the material at the atomic level, a lamella was created, which was then studied using a transmission electron microscope.

Influence of Electrode Cooling on Material Migration among the Electrodes during EDM of Titanium Alloy

2011 ◽  
Vol 264-265 ◽  
pp. 1199-1204 ◽  
Author(s):  
Suleiman Abdulkareem ◽  
Ahsan Ali Khan ◽  
Mohamed Konneh
Keyword(s):  
Liquid Nitrogen ◽  
Electrical Discharge Machining ◽  
Electrically Conductive ◽  
Workpiece Surface ◽  
Hard Metals ◽  
Material Migration ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time ◽  
Dies And Moulds

Electrical discharge machining (EDM) is widely used in the machining of electrically conductive hard metals for the production of dies and moulds. This paper describes an investigation of the effect of electrode cooling on the amount of elements migration from the electrode to the workpiece surface and from the workpiece to the electrode surface. In the present study EDM has been performed with electrodes cooled by liquid nitrogen as well as with electrodes without cooling. Current, pulse-on time, pulse-off time and voltage were taken as the variables during conducting the experiments. The analysis on material migration during EDM was carried out by SEM and EDX. It was observed that EDM with liquid nitrogen reduces material migration and minimizes the surface contamination of both the electrodes.

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.

Machining of B1914 nickel-based superalloy using wire electrical discharge machining

2021 ◽  
pp. 095440892110317
Author(s):  
Katerina Mouralova ◽  
Ales Polzer ◽  
Libor Benes ◽  
Josef Bednar ◽  
Radim Zahradnicek ◽  
...  
Keyword(s):  
Surface Topography ◽  
Discharge Current ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Cutting Speed ◽  
Wire Electrical Discharge Machining ◽  
Nickel Based Superalloy ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time

The unconventional technology of wire electrical discharge machining is a key engineering technology, designed primarily for machining of conventionally difficult machine materials. One of them is nickel alloys, which are majorly used in the aerospace and energy industries. The subject of research in this study was specifically the B1914 nickel-based superalloy, which was subjected to many analyses leading to an overall optimization of its machining using wire electrical discharge machining. In order to determine the effect of machine parameters setup (pulse off time, gap voltage, discharge current, pulse on time and wire feed) on cutting speed, topography, morphology, surface and subsurface layer quality, an extensive Box–Behnken design experiment consisting of 46 rounds was carried out. The analyses of the condition of the surface and subsurface layers were performed, including their chemical composition and changes caused by wire electrical discharge machining. It was found out that the factors like pulse off time, discharge current and pulse on time have the greatest effect on the cutting speed, although from the point of view of surface topography the parameter pulse off time is not significant. The remaining two parameters cause the cutting speed to act against the surface topography i.e. with the increasing cutting speed, the surface topography gets worse and vice versa.

scholarly journals Modelling and experimental investigation of process parameters in WEDM of WC-5.3 % Co using response surface methodology

2012 ◽  
Vol 3 (2) ◽  
pp. 63-72 ◽  
Author(s):  
K. Jangra ◽  
S. Grover
Keyword(s):  
Experimental Data ◽  
Experimental Investigation ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Electrical Discharge Machining ◽  
Cutting Speed ◽  
Performance Characteristics ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Factor Interaction

Abstract. Tungsten carbide-cobalt (WC-Co) composite is a difficult-to-machine material owing to its excellent strength and hardness at elevated temperature. Wire electrical discharge machining (WEDM) is a best alternative for machining of WC-Co composite into intricate and complex shapes. Efficient machining of WC-Co composite on WEDM is a challenging task since it involves large numbers of parameters. Therefore, in present work, experimental investigation has been carried out to determine the influence of important WEDM parameters on machining performance of WC-Co composite. Response surface methodology, which is a collection of mathematical and experimental techniques, was utilised to obtain the experimental data. Using face-centered central composite design, experiments were conducted to investigate and correlate the four input parameters: pulse-on time, pulse-off time, servo voltage and wire feed for three output performance characteristics – cutting speed (CS), surface roughness (SR) and radial overcut (RoC). Using analysis of variance on experimental data, quadratic vs. two-factor interaction (2FI) models have been suggested for CS and RoC while two-factor interaction (2FI) has been proposed for SR. Using these mathematical models, optimal parameters can be determined easily for desired performance characteristics, and hence a trade-off can be made among different performance characteristics.

scholarly journals Performance evaluation of wire electrical discharge machining on Titanium Alloy

2018 ◽  
Vol 1 (1) ◽  
pp. 27-38
Author(s):  
Jun Qi Tan ◽  
Mohd Yazid Abu
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Cutting Speed ◽  
Wire Electrical Discharge Machining ◽  
Machining Parameters ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Machining Parameter

The experimental carried out to aim at the selection of the best condition machining parameter combination for wire electrical discharge machining (WEDM) of titanium alloy (Ti–6Al–4V). By using Design Expert 10 software, a series of experiments were performed by selecting pulse-on time, pulse-off time, servo voltage and peak current as parameters. The responses that considered were cutting speed, material removal rate, sparking gap and surface roughness. Based on ANOVA analysis, the effect from the parameters on the responses was determined. The optimum machining parameters setting for the maximum cutting speed, minimum sparking gap and minimum surface roughness were found by proceed optimization experiment. Then, each optimization response had their own combination setting on WEDM to cut titanium alloy. 3D response surface graph such as dome and bowl shape represent maximum and minimum point for the solutions had shown in the report. Finally, predicted and actual value from the experiment have been calculated for validation.

Optimization and surface modification in electrical discharge machining of AA 6061/SiCp composite using Cu–W electrode

2015 ◽  
Vol 231 (3) ◽  
pp. 332-348 ◽  
Author(s):  
Balbir Singh ◽  
Jatinder Kumar ◽  
Sudhir Kumar
Keyword(s):  
Process Parameters ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Surface Characteristics ◽  
Electrode Wear ◽  
Material Transfer ◽  
Machined Surface ◽  
Recast Layer Thickness ◽  
Pulse On Time ◽  
Pulse Off Time

This paper presents the experimental investigation on the electro-discharge machining of aluminum alloy 6061 reinforced with SiC particles using sintered Cu–W electrode. Experiments have been designed as per central composite rotatable design, using response surface methodology. Machining characteristics such as material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR) have been investigated under the influence of four electrical process parameters; namely peak current, pulse on time, pulse off time, and gap voltage. The process parameters have been optimized to obtain optimal combination of MRR, EWR, and SR. Further, the influence of sintered Cu–W electrode on surface characteristics has been analyzed with scanning electron microscopy, energy dispersive spectroscopy, and Vicker microhardness tests. The results revealed that all the process parameters significantly affect MRR, EWR, and SR. The machined surface properties are modified as a result of material transfer from the electrode. The recast layer thickness is increased at higher setting of electrical parameters. The hardness across the machined surface is also increased by the use of sintered Cu–W electrode.

Mathematical Modeling of Machining Parameters in Electrical Discharge Machining with Cu-B4C Composite Electrode

2012 ◽  
Vol 488-489 ◽  
pp. 871-875
Author(s):  
V. Anandakrishnan ◽  
V. Senthilkumar
Keyword(s):  
Mathematical Models ◽  
Current Pulse ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Machining Parameters ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time ◽  
Selection Of

Copper based metal matrix composite reinforced with Boron Carbide is a newly developed Electrical Discharge Machining (EDM) electrode showing better performance than the conventional copper based electrode. Right selection of machining parameters such as current, pulse on time and pulse off time is one of the most important aspects in EDM. In this paper an attempt has been made to develop mathematical models for relating the Material Removal Rate (MRR), Tool Removal Rate (TRR) and Surface roughness (Ra) to machining parameters (current, pulse-on time and pulse-off time). Furthermore, a study was carried out to analyze thSubscript texte effects of machining parameters on various performance parameters such as, MRR, TRR and Ra. The results of Analysis of Variance (ANOVA) indicate that the proposed mathematical models, can adequately describe the performance within the limits of the factors being studied. Response surface modeling is used to develop surface and contour graphs to analyze the effects of EDM input parameters on outer parameters.

Surface Roughness at Wire Electrical Discharge Machining

2015 ◽  
Vol 760 ◽  
pp. 551-556 ◽  
Author(s):  
Oana Dodun ◽  
Laurenţiu Slătineanu ◽  
Margareta Coteaţă ◽  
Vasile Merticaru ◽  
Gheorghe Nagîţ
Keyword(s):  
Surface Roughness ◽  
Empirical Model ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Roughness Parameter ◽  
Wire Electrical Discharge Machining ◽  
Power Type ◽  
Surface Roughness Parameter ◽  
Pulse On Time ◽  
Pulse Off Time

Wire electrical discharge machining is a machining method by which parts having various contours could be detached from plate workpieces. The method uses the electrical discharges developed between the workpiece and the wire tool electrode found in an axial motion, when in the work zone a dielectric fluid is recirculated. In order to highlight the influence exerted by some input process factors on the surface roughness parameter Ra in case of a workpiece made of an alloyed steel, a factorial experiment with six independent variables at two variation levels was designed and materialized. As input factors, one used the workpiece thickness, pulse on time, pulse off-time, wire axial tensile force, current intensity average amplitude defined by setting button position and travelling wire electrode speed. By mathematical processing of the experimental results, empirical models were established. Om the base of a power type empirical model, graphical representations aiming to highlight the influence of some input factors on the surface roughness parameter Ra were achieved. The power type empirical model facilitated establishing of order of factors able to exert influence on the surface roughness parameter Ra at wire electrical discharge machining.

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