Parametric investigation of tool wear rate in EDM of Fe-based shape memory alloy: microstructural analysis and optimization using genetic algorithm

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ranjit Singh ◽  
Ravi Pratap Singh ◽  
Rajeev Trehan
Keyword(s):  
Tool Wear ◽  
Tool Electrode ◽  
Tool Wear Rate ◽  
Sem Images ◽  
Peak Current ◽  
Content Type ◽  
Desirability Approach ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time

Purpose This study aims to experimentally investigate the influence of considered process parameters, i.e. pulse on time, pulse off time, peak current and gap voltage, on tool wear rate (TWR) in electrical discharge machining (EDM) of iron (Fe)-based shape memory alloy (SMA) through designed experiments. The parametric optimization for TWR has also been attempted using the desirability approach and genetic algorithm (GA). Design/methodology/approach The response surface methodology (RSM) in the form of Box–Behnken design has been used to scheme out the experiments. The influence of considered process inputs has also been observed through variance analysis. The reliability and fitness of the developed mathematical model have been established with test results. Microstructure analysis of machined samples has also been evaluated and analyzed using a scanning electron microscope (SEM). SEM images revealed the surface characteristics such as micro-cracks, craters and voids on the tool electrode surface. SEM images provide information about the surface integrity and type of wear on the surface of the tool electrode. Findings The input parameters, namely, pulse on time and pulse off time, are major influential factors impacting the TWR. High TWR has been reported at large pulse on time and small pulse off time conditions whereas higher TWR is reported at high peak current input settings. The maximum and minimum TWR values obtained are 0.073 g/min and 0.017 g/min, respectively. The optimization with desirability approach and GA reveals the best parametric values for TWR i.e. 0.01581 g/min and 0.00875 g/min at parametric combination as pulse on time = 60.83 µs, pulse off time = 112.16 µs, peak current = 18.64 A and gap voltage = 59.55 V, and pulse on time = 60 µs, pulse off time = 120 µs, peak current = 12 A and gap voltage = 40 V, correspondingly. Research limitations/implications Proposed work has no limitations. Originality/value SMAs have been well known for their superior and excellent properties, which make them an eligible candidate of paramount importance in real-life industrial applications such as orthopedic implants, actuators, micro tools, stents, coupling, sealing elements, aerospace components, defense instruments, manufacturing elements and bio-medical appliances. However, its effective and productive processing is still a challenge. Tool wear study while processing of SMAs in EDM process is an area which has been less investigated and of major concern for exploring the various properties of the tool and wear in it. Also, the developed mathematical model for TWR through the RSM approach will be helpful in industrial revelation.

Optimization of Machining Parameters on Tool Wear Rate of Ti-6Al-4V through EDM Using Copper Tungsten Electrode: A Statistical Approach

2010 ◽  
Vol 152-153 ◽  
pp. 1595-1602 ◽  
Author(s):  
M.M. Rahman ◽  
Md. Ashikur Rahman Khan ◽  
K. Kadirgama ◽  
M.M. Noor ◽  
Rosli A. Bakar
Keyword(s):  
Wear Rate ◽  
Tool Wear ◽  
Machining Process ◽  
Electrode Wear ◽  
Tool Wear Rate ◽  
Peak Current ◽  
Long Pulse ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time

Electrical discharge machining (EDM) is relatively modern machining process having distinct advantages over other machining processes and able to machine Ti-alloys effectively. This paper attempts to investigate the effects of peak ampere, pulse on time and pulse off time on tool wear rate (TWR) of titanium alloy Ti-6Al-4V in EDM utilizing copper tungsten as an electrode and positive polarity of the electrode. A mathematical model for electrode wear rate is developed in this paper. Design of experiments method and response surface methodology techniques are implemented. The validity test of the fit and adequacy of the proposed models has been carried out through analysis of variance. It can be seen that as the peak current increases the TWR decreases till certain ampere and then increases. The excellent surface finish is investigated in this study at short pulse on time and in contrast the long pulse duration causes the lowest TWR. Long pulse off time provides minimum TWR and the impact of pulse interval on TWR depends on peak current. The result leads to wear rate of electrode and economical industrial machining by optimizing the input parameters.

Research on Tool Wear Rate of Powder Mixed near Dry Electrical Discharge Machining

2013 ◽  
Vol 652-654 ◽  
pp. 2222-2227 ◽  
Author(s):  
Xue Bai ◽  
Qin He Zhang ◽  
Ting Yi Yang ◽  
Jian Hua Zhang ◽  
Jing Tan
Keyword(s):  
Wear Rate ◽  
Tool Wear ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Tool Wear Rate ◽  
Powder Concentration ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time ◽  
Dry Electrical Discharge Machining

Powder mixed near dry electrical discharge machining (PMND-EDM) is one of the novel EDM processes, which uses gas-liquid-powder mixture as the dielectric medium. The tool wear rate (TWR) in PMND-EDM is researched based on single factor experiments. Effects of process parameters, such as peak current, pulse on time, pulse off time, flow rate, powder concentration, tool rotational speed and air pressure, on TWR are found out. TWR increases with the increase of peak current. TWR decreases with increasing of pulse on time. TWR increases firstly and then decreases while pulse off time increases. Increase of flow rate results in the increase of TWR. With the increase of powder concentration, TWR increases firstly and then decreases. Existence of tool rotation facilities decrease of TWR, however, further increase of rotational speed leads to increase of TWR. Increase of air pressure leads to lower TWR.

scholarly journals Findings of performance evaluation of EDM for different materials of electrodes and work pieces- a review

2018 ◽  
Vol 7 (4.5) ◽  
pp. 542
Author(s):  
Harshalkumar R. Mundane ◽  
Dr. A. V. Kale ◽  
Dr. J. P. Giri
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Performance Measure ◽  
Machining Process ◽  
Machining Parameters ◽  
Spark Erosion ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time ◽  
Time Pulse

EDM (Spark erosion) is non-conventional machining process which uses as removing unwanted material by electrical spark erosion. EDM Machining parameters affecting to the performance and the industries goal is to produce high quality of product with less time consuming and cost. To achieve these goals, optimizing the machining parameters such as pulse on time, pulse off time, cutting speed, depth of cut, duty cycle, arc gap, voltage etc. The performance measure of EDM is calculated on the basis of Material Remove Rate(MRR), Tool Wear Rate(TWR), and Surface Roughness(SR).The main objective of present work is to investigate of the influence of input EDM (Electro Discharge Machining) parameters on machining characteristics like surface roughness and the effects of various EDM process parameters such as pulse on time, pulse off time, servo voltage, peak current, dielectric flow rate, on different process response parameters such as material removal rate (MRR), surface roughness (Ra), Kerf (width of Cut), tool wear ratio(TWR)and surface integrity factors. In this paper few selected research paper related to Die-sinker EDM with effect of MRR, TWR, surface roughness (SR) and work piece material have been discussed.   

Evaluation of Cutting Rate for Ultrasonic Work Piece Vibration Assisted Wire-EDM under Varying Amplitude of Vibration

2020 ◽  
Vol 979 ◽  
pp. 149-156
Author(s):  
Sanjay Kumar ◽  
Sandeep Grover ◽  
Ravinder S. Walia
Keyword(s):  
Cutting Speed ◽  
Work Piece ◽  
Cutting Condition ◽  
Time Level ◽  
Peak Current ◽  
Optimum Cutting ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time ◽  
Level 2

This paper present an investigation on cutting speed of ultrasonic vibration assisted wire electrical discharge machining (US-WEDM) for High carbon high chromium D3 Steel. An extensive research study was carried out with an aim to select the optimum cutting condition with the varying amplitude of vibration in order to get the optimum cutting speed for the proposed set-up. The process was mathematically modeled using the response parameters, i.e. cutting speed under a range of control parameters and the main influencing factors were determined for cutting speed criteria Taguchi’s experimentation methodology indicated the contribution of amplitude of vibration (P=6.16%), pulse on time (P=14.54%), pulse off time (P=73.16%) and peak current (P=5.94%). Finally, the optimum parametric setting for different cutting speed arising out of study has synthesized as amplitude of vibration at level 3 (18μm), peak current level 1 (100 units), pulse on time level 2 (118 μ sec) and pulse off time level 2 (46 μ sec) and analyses in this study.

Optimization of Electric Discharge Machining Parameters of Al-7%Si-4%Mg with 20% of Red Mud Metal Matrix Composites

2014 ◽  
Vol 941-944 ◽  
pp. 1973-1976
Author(s):  
B. Geetha ◽  
K. Ganesan
Keyword(s):  
Surface Roughness ◽  
Wear Rate ◽  
Tool Wear ◽  
Material Removal Rate ◽  
Electric Discharge ◽  
Material Removal ◽  
Removal Rate ◽  
Tool Wear Rate ◽  
Peak Current ◽  
Pulse On Time

An investigation was carried out to find out the influence of process parameters on surface roughness (SR) and material removal rate (MRR) in electric discharge machine of Al-7%Si-4%Mg with 20% of red mud Metal Matrix Composites since electric discharge machining is a thermo-electric machining process, an electronic die sinking electric discharge machine was used to drill holes in the composite work piece, copper is used as tool material. Experiment was carried out to find surface roughness, material removal rate and tool wear rate by varying the peak current, flushing pressure of dielectric fluid and pulse on time. It was found that the surface roughness of composite metal increases with the increase peak current ,pulse on time and flushing pressure due larger and deeper craters on the drilled surface. It was also found that there was increase in metal removal rate with the increase in peak current and flushing pressure and slightly decreases with the increase in pulse on time due carbon deposits on the electrodes. Experimental analysis is carried using Taguchi’s Design of Experiment method with various parameters like peak current, flushing pressure of dielectric fluid and pulse on time to identify the key factors that influence the surface roughness, material removal rate and tool wear rate. It was found that the peak current was the most significant parameter that influences surface roughness, material removal rate and tool wear rate. The Taguchi experiments results confirm the actual results obtained from the numerical calculation.

CFRP composite drilling through electrical discharge machining using aluminum as fixture plate

2021 ◽  
pp. 095440622110586
Author(s):  
Suvranshu Pattanayak ◽  
Ananda Kumar Sahoo ◽  
Susanta Kumar Sahoo
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Quality Attributes ◽  
Critical Parameters ◽  
Burr Formation ◽  
Hole Quality ◽  
Peak Current ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time

Recent developments in manufacturing require holes on composite materials, especially on the carbon fiber reinforced polymer (CFRP) with smooth hole periphery, low delamination, burr formation, taper, better circularity, and a high processing speed. Its non-conductive surface (epoxy layering) limits its machining through electrical discharge machining (EDM). To overcome this limitation, an aluminum fixture has been designed to guide the copper electrode of EDM for producing holes on a CFRP sheet of 1 mm thickness at low machining complexity, cost, time, delamination, burr in hole periphery and without affecting the material’s surface quality and performance. Even components with high geometrical complexity can also be drilled through this approach. Here, a multi-quality analysis called grey relational analysis is developed for examining the hole quality attributes, considering peak current, pulse on and off time, and flushing pressure as input parameters. This approach points out the optimum factor level setting and critical parameters (pulse-on time and peak current) that regulate the hole attributes (entrance and exit diameter, circularity, taper, material removal, and tool wear rate). An artificial neural network model has been designed and trained through experimental data sets. This model can also be adopted during the determination of hole quality attributes when the parameter settings are beyond a defined boundary, as the regression analysis value is very close to 1, and model performance is 4.99e-10. Peak current = 4 A, pulse-on time = 25 µs, pulse-off time=25 µs, and flushing pressure = 0.6 MPa were the optimum drilling parameters. In the initial hole, average burr length is 391.75 μm, and delamination of 539.3 μm is noticed. But burr formation is very negligible with delamination of 350.7 μm being observed with uniform circularity (0.979), low taper angle (−0.81354°), and TWR (0.000069 g/min) under optimum drilling conditions through this drilling approach.

Modeling and Spark Erosion Drilling Process Optimization of Inconel 718 Using RSM Technique

2019 ◽  
Vol 18 (01) ◽  
pp. 57-83 ◽  
Author(s):  
Rajeev Kumar ◽  
Somnath Chattopadhyaya ◽  
G. K. Singh ◽  
Umesh Kumar Vates
Keyword(s):  
Surface Roughness ◽  
Wear Rate ◽  
Tool Wear ◽  
Discharge Current ◽  
Inconel 718 ◽  
Removal Rate ◽  
Tool Wear Rate ◽  
Spark Erosion ◽  
Pulse On Time ◽  
Pulse Off Time

Electrical discharge machining with rotary tool is known as electric discharge drilling (EDD) which is being widely used for machining the difficult-to-cut materials like super alloy, ceramics and composite materials. Present research work has been introduced to find the impact of four influencing input factors discharge current (C), pulse off time ([Formula: see text]), pulse-on time ([Formula: see text]) and drill speed (S) on the response, tool wear rate (TWR), metal removal rate (MRR) and Centre line average value of surface roughness (Ra). The spark erosion drilling was performed on the Inconel 718 with rotating copper electrode. The major performances characteristics material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) are to be evaluated with consultation of Response Surface Methodology (RSM) techniques. The central composite rotatable design (CCRD) has been reported to plan the experimental design and developing the model for prediction of data within the range of investigation. ANOVA test was also carried out to check the adequacy for development of models. It has been evaluated that discharge current, [Formula: see text], and [Formula: see text] have been found as most significant factors that effects on the performance measures. The models have 86.02, 84.29, and 83.15% values of correlation coefficient (R2) for MRR, TWR and Ra whereas the adjusted R2 (R2 adj) are 73.80%, 70.55%, and 68.41% for MRR, TWR and SR, respectively.

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

2020 ◽  
Vol 16 (5) ◽  
pp. 1189-1202 ◽  
Author(s):  
Harvinder Singh ◽  
Vinod Kumar ◽  
Jathinder Kapoor
Keyword(s):  
Removal Efficiency ◽  
Process Parameters ◽  
Material Removal ◽  
Kerf Width ◽  
Content Type ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Wedm Process ◽  
Nimonic 75 ◽  
Off Time

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.

Influence of ceramic Al2O3 particulates on performance measures and surface characteristics during sinker EDM of stir cast AMMCs

2019 ◽  
Vol 16 (4) ◽  
pp. 526-538 ◽  
Author(s):  
Akhil Khajuria ◽  
Modassir Akhtar ◽  
Manish Kumar Pandey ◽  
Mayur Pratap Singh ◽  
Ankush Raina ◽  
...  
Keyword(s):  
Performance Measures ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Base Material ◽  
Machining Parameters ◽  
Content Type ◽  
Weight Percentage ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time

Purpose AA2014 is a copper-based alloy and is typically used for production of complex machined components, given its better machinability. The purpose of this paper was to study the effects of variation in weight percentage of ceramic Al2O3 particulates during electrical discharge machining (EDM) of stir cast AA2014 composites. Scanning electron microscopy (SEM) examination was carried out to study characteristics of EDMed surface of Al2O3/AA2014 composites. Design/methodology/approach The effect of machining parameters on performance measures during sinker EDM of stir cast Al2O3/AA2014 composites was examined by “one factor at a time” (OFAT) method. The stir cast samples were obtained by using three levels of weight percentage of Al2O3 particulates, i.e. 0 Wt.%, 10 Wt.% and 20 Wt.% with density 1.87 g/cc, 2.35 g/cc and 2.98 g/cc respectively. Machining parameters varied were peak current (1-30 amp), discharge voltage (30-100 V), pulse on time (15-300 µs) and pulse off time (15-450 µs) to study their influence on material removal rate (MRR), tool wear rate (TWR) and surface roughness (SR). Findings MRR and SR decreased with an increase in weight percentage of ceramic Al2O3 particulates at the expense of TWR. This was attributed to increased microhardness for reinforced stir cast composites. However, microhardness of EDMed samples at fixed values of machining parameters, i.e. 9 amp current, 60 V voltage, 90 µs pulse off time and 90 µs pulse on time reduced by 58.34, 52.25 and 46.85 per cent for stir cast AA2014, 10 Wt.% Al2O3/AA2014 and 20 Wt.% Al2O3/AA2014, respectively. SEM and quantitative energy dispersive spectroscopy (EDS) analysis revealed ceramic Al2O3 particulate thermal spalling in 20 Wt.% Al2O3/AA2014 composite. This was because of increased particulate weight percentage leading to steep temperature gradients in between layers of base material and heat affected zone. Originality/value This work was an essential step to assess the machinability for material design of Al2O3 reinforced aluminium metal matrix composites (AMMCs). Experimental investigation on sinker EDM of high weight fraction of particulates in AA2014, i.e. 10 Wt.% Al2O3 and 20 Wt.% Al2O3, has not been reported in archival literature. The AMMCs were EDMed at variable peak currents, voltages, pulse on and pulse off times. The effects of process parameters on MRR, TWR and SR were analysed with comparisons made to show the effect of Al2O3 particulate contents.

Performance Evaluation of Electrical Discharge Machining Die Sinking on Stainless Steel 316L Using Copper Impregnated Graphite

2014 ◽  
Vol 660 ◽  
pp. 48-54 ◽  
Author(s):  
Wahaizad Safiei ◽  
Safian Sharif ◽  
Ahmad Fairuz Mansor ◽  
Mohd Halimudin Mohd Isa
Keyword(s):  
Stainless Steel ◽  
Removal Rate ◽  
Dimensional Accuracy ◽  
Time Range ◽  
Electrode Wear ◽  
Stainless Steel 316L ◽  
Peak Current ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time

This study presents the results of experimental studies carried out to conduct a comprehensive investigation on the influence of Electrical Discharge Machining (EDM) input parameters on characteristics of EDM process. The machining parameters include peak current, servo voltage, pulse ON time and pulse OFF time. The study was conducted using 2 levels of Full Factorial Method in Design of Experiments. The design expert software employed to perform all the data analysis for Full Factorial and Central Composite Design (CCD) experiments. This study evaluates the machining performance of the Stainless Steel 316L using Sodick EDM linear motor series AM3L which employed Copper impregnated graphite diameter 7.0 mm as the tool electrode. The response variables are material removal rate (MRR), electrode wear rate (EWR), surface roughness (SR) and dimensional accuracy. The result shows that the peak current was the most significant factors to all variable responses. The servo voltage does not have significant effects to the machining responses in RSM. Higher current produced higher MRR, EWR, SR and Dimensional Accuracy. Maximum MRR was obtained at peak current range from 27amp to 38amp, pulse on time range from 120μs to 145μs and 60μs of pulse off time. Maximum EWR was obtained at peak current range from 27amp to 37amp, pulse on time range from 140μs to 160μs and 60μs of pulse off time. High probably, the minimum EWR only can be obtained if peak current parameter sets greater than 45amp. Lower dimensional accuracy and SR obtain at 5amp of pulse on time. Higher pulse off time produced lower MRR and EWR.Keywords: EDM Die sinking, Stainless Steel 316L, Copper Impregnated Graphite Electrode, Response Surface Methodology, Surface Roughness, Material Removal Rate, Electrode Wear Rate, Dimensional Accuracy

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