Electrical Discharge Machining Of Inconel Research Articles

Surface Morphology Investigations during Multi-walled Carbon Nanotubes and Nanographene Mixed Electrical Discharge Machining of Inconel 825

Surface Morphology Investigations during Multi-walled Carbon Nanotubes and Nanographene Mixed Electrical Discharge Machining of Inconel 825

Measurement and optimization of power consumption and aerosol emissions in magnetic field-assisted electrical discharge machining of Inconel 718

Measurement and optimization of power consumption and aerosol emissions in magnetic field-assisted electrical discharge machining of Inconel 718

An effect of process parameters during wire cut electrical discharge machining of Inconel 738

In the recent days, super alloys especially nickel based materials are used more than 50% of aerospace gas turbine components such as turbine disc, blades etc., It becomes very hard to shape these materials with the use of traditional machining processes due to its improved strength at higher temperature. To overcome the issues faced during conventional machining, the various advanced machining techniques are tried for machining these super alloys. In the present study, Inconel 738 was cut by wire electrical discharge machining using 0.25 mm diameter copper wire. Demineralized water was used as dielectric fluid between tool and workpiece electrode. During the process, voltage, wire feed rate, time of pulse on and pulse off were adjusted at four different values and totally sixteen slots were cut to analyze the machining characteristics. The machined surfaces were tested for its surface finish, rate of material removal and kerf width. The ANOVA was performed using Minitab software to find out the optimized variables and percentage contribution of each parameter in providing the influencing results. Wire feed rate was the most influencing parameter to have the lowest kerf width. As far as Material removal rate, the four parameters were had the significant impact in increasing the MRR. Voltage is the important process parameter to reduce the surface roughness.

Powder mixed electrical discharge machining of Inconel 718: investigation on material removal rate and surface roughness

Powder mixed electrical discharge machining of Inconel 718: investigation on material removal rate and surface roughness

Response Surface Methodology and Artificial Neural Network-Based Models for Predicting Performance of Wire Electrical Discharge Machining of Inconel 718 Alloy

This paper deals with the development and comparison of prediction models established using response surface methodology (RSM) and artificial neural network (ANN) for a wire electrical discharge machining (WEDM) process. The WEDM experiments were designed using central composite design (CCD) for machining of Inconel 718 superalloy. During experimentation, the pulse-on-time (TON), pulse-off-time (TOFF), servo-voltage (SV), peak current (IP), and wire tension (WT) were chosen as control factors, whereas, the kerf width (Kf), surface roughness (Ra), and materials removal rate (MRR) were selected as performance attributes. The analysis of variance tests was performed to identify the control factors that significantly affect the performance attributes. The double hidden layer ANN model was developed using a back-propagation ANN algorithm, trained by the experimental results. The prediction accuracy of the established ANN model was found to be superior to the RSM model. Finally, the Non-Dominated Sorting Genetic Algorithm-II (NSGA- II) was implemented to determine the optimum WEDM conditions from multiple objectives.

An experimental parametric analysis on performance characteristics in wire electric discharge machining of Inconel 718

Wire cut electrical discharge machining was identified as a good alternative to conventional machining for machining super alloys that possess low machinability. In the present work, effect of wire tension along with current, pulse on time, and pulse off time on the performance characteristics such as spark gap, surface roughness, amplitude of wire vibration, and cutting rate were studied in wire cut electrical discharge machining of Inconel 718 metal. Experiments were conducted at five levels of the process parameters as per orthogonal array of L25 and their results were collected. These experimental results were analyzed and the interaction effect of wire tension along with current, pulse on time, and pulse off time on performance characteristics was studied using analysis of variance. Response models were developed for the four responses in terms of process parameters and the accuracy of such models was tested. In addition to the above studies, effect of the wire displacement on the kerf size, cutting rate was studied. Spark energy was also estimated for all the experiments and its effect on the performance characteristics was studied. The response models developed in this study were able to predict the experimental results i.e. amplitude of wire vibration, surface roughness, cutting rate, and spark gap with an accuracy of R2 values of 1.0, 0.96, 0.88, and 0.99, respectively. Interaction effect of current and wire tension was found to have the most significant effect on the amplitude of cutter vibration and surface roughness.

Investigation of material removal rate and surface roughness during wire electrical discharge machining (WEDM) of Inconel 625 super alloy by cryogenic treated tool electrode

The present investigation focuses the effect of process parameters on material removal rate (MRR) and surface roughness (Ra) in wire electric discharge machining of Inconel 625. Machining was done by using a normal zinc coated wire and cryogenic treated zinc coated wire. The experiments were performed by considering different process parameters viz. tool electrode, current intensity, pulse on time, pulse off time, wire feed and wire tension. The thickness of work material and dia. of wire are kept constant. Taguchi L18 (21*35) orthogonal array of experimental design is used to perform the experiments. Analysis of variance (ANOVA) is employed to optimize the material removal rate and surface roughness. Based on analysis it is found that pulse on time, tool electrode and current intensity are the significant parameters that affect the material removal rate and surface roughness. The scanning electron microscopy (SEM) are used to identify the microstructure of the machined work piece.

Electrical discharge machining of Inconel 825 using cryogenically treated copper electrode: Emphasis on surface integrity and metallurgical characteristics

In the present work, analysis of surface integrity and metallurgical characteristics of the machined Inconel 825 work surface has been carried out in relation to Electrical Discharge Machining (EDM) using Cryogenically Treated Tool (CTT) in comparison with Non Treated Tool (NTT). Degree of severity of surface cracking as well as formation of white layer onto the EDMed Inconel 825 work surface has been investigated herein. The process physics of EDM using CTT has been explained with scientific relevance to EDAX, XRD, residual stress as well as micro-hardness test data of the test samples. For a constant setting of process parameters [Peak current (IP)=10A; Pulse-on time (Ton)=100μs; Duty factor (τ)=85%], surface crack density has been found relatively less (∼73%) for the EDMed Inconel 825 work surface obtained by using CTT, as compared to the case of NTT. However, relatively thick white layer (∼26%) has been attributed to the EDMed Inconel 825 specimen obtained by using CTT, as compared to the case of NTT (for a common parameters setting: IP=6A;Ton=300μs; τ=85%). Additionally, effects of cryogenic treatment of tool electrode have also been discussed emphasizing aspects of tool life, extent of carbon deposition at the bottom and edge of the electrode, and tool shape retention capability. As compared to NTT, carbon (possibly carbide) layer (deposited at the edge of the tool electrode) of relatively low thickness value (∼75%) has been observed for CTT.

Experimental Investigation and Optimization of Process Parameters of Wire Electrical Discharge Machining Process in Cutting of Inconel 740 Alloys

Objectives: To determine optimum values of machining parameters for attaining economical and competent performance of wire EDM and analyze the observed results statistically and predict the optimal values of MRR and surface roughness. Methods/Statistical Analysis: (i) L 18 orthogonal arrays of Taguchi method is adopted for experimental design and analysis of results. (ii) ANOVA technique is carried out to determine the significant cutting parameters of wire EDM, which influences the output factors. (iii) Response surface methodology has been utilized for statistical evaluation and optimization MRR and surface roughness. Findings: (i) A feasible set of cutting factors which maximizes the MRR and minimize surface roughness has been obtained through statistical analysis using RSM. (ii) It is acquired that cutting voltage is the most substantial input factor, which has the greatest impact on MRR as well as surface roughness in wire electrical discharge machining of Inconel 718. Applications/Improvements: The obtained feasible set of cutting factors could be utilized at the time of further experiments of wire electrical discharge machining of Inconel 718. The research works would be employed in aerospace, tool and die, and automobile industries in machining of nickel alloys.

Grey Relational Optimization of Powder Mixed Near-Dry Wire Cut Electrical Discharge Machining of Inconel 718 Alloy

Grey Relational Optimization of Powder Mixed Near-Dry Wire Cut Electrical Discharge Machining of Inconel 718 Alloy

Investigation of the surface integrity characteristics in wire electrical discharge machining of Inconel 617

The wire electrical discharge machining is one of the best options for machining of high strength materials like Inconel 617. In this study, the effects of wire electrical discharge machining input parameters, such as pulse current and pulse duration on micro-hardness of machined surfaces and subsurface and also density of created surface cracks were investigated. Also the energy dispersive X-ray spectroscopy technique was used to elemental analysis of machined workpiece. The results of this study showed that increasing pulse current and pulse duration, decreases surface micro-hardness while subsurface micro-hardness is increased by increasing pulse duration. Also subsurface micro-hardness is increased by increasing pulse current up to 10 A, but after that the subsurface micro-hardness is decreased. According to the results, the micro-hardness of workpiece is reduced by increasing the distance from the top surface. Also the surface crack density is increased by increasing pulse current and pulse duration first, but it is decreased by increasing more of these two parameters.

Optimization of micro milling electrical discharge machining of Inconel 718 by Grey-Taguchi method

The optimization of micro milling electrical discharge machining (EDM) process parameters of Inconel 718 alloy to achieve multiple performance characteristics such as low electrode wear, high material removal rate and low working gap was investigated by the Grey-Taguchi method. The influences of peak current, pulse on-time, pulse off-time and spark gap on electrode wear (EW), material removal rate (MRR) and working gap (WG) in the micro milling electrical discharge machining of Inconel 718 were analyzed. The experimental results show that the electrode wear decreases from 5.6×10−9 to 5.2×10−9 mm3/min, the material removal rate increases from 0.47×10−8 to 1.68×10−8 mm3/min, and the working gap decreases from 1.27 to 1.19 μm under optimal micro milling electrical discharge machining process parameters. Hence, it is clearly shown that multiple performance characteristics can be improved by using the Grey-Taguchi method.

Evaluation of Surface Quality during Electrical Discharge Machining of Inconel 718 with Powder Metallurgy Electrodes

In recent years, researchers have reported powder metallurgy processed electrodes as alternative tooling for electrical discharge machining (EDM). The present experimental study evaluates the quality of machined surface during electrical discharge machining (EDM) of Inconel 718 alloy steel with powder metallurgy (PM) processed electrodes. The investigated process parameters were polarity, electrode type, peek current, pulse on time, duty cycle, gap voltage, retract distance and flushing pressure. The surface quality was measured in terms of surface roughness (Ra). An orthogonal array L36 (21X 37) based on Taguchi methodology was applied to plan and design experiments. Experimental data was statistically analyzed using analysis of variance (ANOVA) and optimum condition was achieved for evaluation criteria. It was concluded that polarity, electrode type, peek current, have significant effect on surface quality and minimum Ra is obtained with CuW2080 electrode at minimum current and negative polarity. Deposition of tungsten with CuW2080 (80%W 20%Cu) electrode was confirmed by energy dispersion spectrum (EDS) of the machined surface.

Multi-objective parametric optimisation during electrical discharge machining of Inconel 718 with different electrodes

This paper presents multi-objective parametric optimisation of electrical discharge machining (EDM) process by the Taguchi method with grey relation analysis. Experimental investigations are performed on Inconel 718 with three different electrodes. Orthogonal array (L36) is used to identify the effect of process parameters (viz. polarity, electrode type, peak current, pulse on time, duty cycle, gap voltage, retract distance and flushing pressure) on the performance characteristics in terms of material removal rate surface roughness and tool wear rate. Using grey relational analysis, grey relational grade has been determined, which effectively represents the aggregate of different process attributes. As a result, a multi-objective parametric optimisation is converted into optimisation of a single grey relational grade. Experimental results have shown that utilisation of optimal machining parameter combination enhances a significant improvement of the grey relation grade and the grey relation grade is improved by 8.72%.