scholarly journals Experimental investigation on electro-discharge surface modification phenomenon of P20+Ni die steel using green P/M composite electrode

2021 ◽  
Vol 15 (3) ◽  
pp. 8390-8404
Author(s):  
JAYANTIGAR L RAMDATTI ◽  
A. V. Gohil ◽  
K. G. Dave

In the present work, attempts have been made to optimize the EDM process with an aspect of surface modification of AISI P20+Ni die steel using powder metallurgy (P/M) electrode. Experiments have been performed according to central composite rotatable (CCD) design using response surface methodology (RSM). Effects of compaction pressure (Cp), peak current (Ip), pulse-on time (Ton), and duty cycle (τ) were correlated with surface roughness (SR) and microhardness (MH). Adequacy of mathematical model has been checked by performing ANOVA. Composite desirability approach was used to obtain optimal set of parameters for minimum SR and maximum MH. The errors between the predicted and experimental value of responses at the optimal set of parameters for SR and MH maintain within 5.26% and -3.64% respectively. Scanning electron microscope and energy dispersive spectroscopy analysis confirmed the transfer of P/M electrode material on the work surface. The result indicates three times improvement in microhardness of EDMed surface.

Author(s):  
Anshuman Kumar Sahu ◽  
Siba Sankar Mahapatra ◽  
Suman Chatterjee

Electrical discharge machining (EDM), a thermo-mechanical machining process, is used in producing a complicated intrinsic cavity in difficult-to-machine materials with excellent surface finish. One of the major disadvantages of EDM process is the tool wear. However, tool wear can be used advantageously for coating purpose. Coating is a unique method of EDM process by the use of electrode prepared through powder metallurgy (PM) route. This process is also cheaper as compared to other deposition processes like chemical vapor deposition (CVD) and physical vapor deposition (PVD) processes. Therefore, electrical discharge coating (EDC) can be employed in industries for coating purpose where the corrosion resistance and hardness of the work piece material are required to be increased for their use in a wide range of environmental condition. Copper (Cu) and tungsten (W) powders in weight percentage of 30 and 70 respectively are used for the preparation of the tool electrode. The PM process parameters like compaction pressure (CP) and sintering temperature (ST) are varied to prepare the tool electrodes. The density and electrical conductivity of the electrodes are found to increase with an increase in compaction pressure and sintering temperature. The substrate on which coating is made is chosen as AISI 1040 stainless steel with EDM oil as the dielectric fluid. During coating, the influence of parameters like discharge current (Ip), duty cycle (τ) and pulse-on-time (Ton) on material deposition ratio (MDR), Average surface roughness (Ra), coated layer thickness (LT) and micro-hardness of the coated layer are studied. To reduce the number of the experiment, Taguchi’s L18 orthogonal array has been used. To find out the best parametric combination that can simultaneously optimize all performance measures, multi-objective optimization on the basis of ratio analysis (MOORA) method combined with Firefly algorithm has been employed.


2021 ◽  
Vol 27 (2) ◽  
pp. 112-118
Author(s):  
Mohd Faizan Hasan ◽  
Prem Kumar Bharti ◽  
Mohd Reyaz Ur Rahim

Abstract The work investigated the effect on wire offset and surface morphology, with input process parameters as peak current, pulse on time, wire tension over Die Steel D3. Some of experiments were performed by using response surface methodology (RSM) as the design of experiment with central composite design (CCD) technique for the analysis. The ANOVA results annotate that the model is significant. Wire Tension and peak current are observed to have major impact on wire offset during machining operation and surface morphology. The scanning electron microscope (SEM) images confirmed that the thermal stresses produced during the machining of the workpiece resulted in the development of microcracks, craters and spherical module. Due to higher thermal gradient i.e., higher peak current and pulse on-time larger cracks and melted deposits were observed.


2011 ◽  
Vol 701 ◽  
pp. 43-59 ◽  
Author(s):  
Anirban Bhattacharya ◽  
Ajay Batish ◽  
Gurpreet Singh

This paper investigates the effect of electric discharge machining (EDM) process parameters and powder mixed in dielectric on surface properties of three die steel work materials; namely High Carbon High Chromium (HCHCr), EN 31 and Hot Die Steel (HDS). The mechanism of material deposition from the suspended powder and/or tool electrode is reported. Current emerged as the most significant factor affecting the microhardness along with powder mixed in the dielectric and electrode material. Amongst the two electrode materials, copper-tungsten along with tungsten powder had the best microhardness. Selected samples were analyzed for X-ray Diffraction (XRD) followed by microstructure analysis using a Scanning Electron Microscope (SEM). The results showed significant material transfer from the electrode as well as powder either in free form or in compound form. It was concluded that surface modification of die steels can be done by incorporating simple modifications in the EDM set-up resulting in higher microhardness and superior wear resistance of the machined surface.


2015 ◽  
Vol 772 ◽  
pp. 245-249
Author(s):  
A. Ramamurthy ◽  
R. Sivaramakrishnan ◽  
S. Venugopal ◽  
T. Muthuramalingam

It is very important and complexity to find the optimum values of wire EDM process parameters and contribution of each parameter to attain the better performance characteristics. In this study, an attempt has been made to optimize those parameters while machining the titanium alloy. Since the process involves more one than one response parameter, it is essential to carry out the multi-response optimization methodology .The experiments have been conducted with different levels of input factors such as pulse on time,pulse off time and wire tension based on Taguchi L9 orthogonal table.Wire EDM optimal process parameter has been identified using grey relational analysis and significant parameter has been determined by analysis of variance. Experimental results have indicated that the multi-response characteristic such as material removal rate and surface roughness can be improved effectively through grey relational analysis.


2018 ◽  
Vol 7 (2.8) ◽  
pp. 10
Author(s):  
A VS Ram Prasad ◽  
Koona Ramji ◽  
B Raghu Kumar

Machining of Titanium alloys is difficult due to their chemical and physical properties namely excellent strength, chemical reactivity and low thermal conductivity. Traditional machining of such materials leads to formation of continuous chips and tool bits are subjected to chatter which leads to formation of poor surface on machined surface. In this study, Wire-EDM one of the most popular unconventional machining process which was used to machine such difficult-to-cut materials. Effect of Wire-EDM process parameters namely peak current, pulse-on- time, pulse-off-time, servo voltage on MRRand SR was investigated by Taguchi method. 0.25 mm brass wire was used in this process as electrode material. A surface roughness tester (Surftest 301) was used to measure surface roughness value of the machined work surface. A multi-response optimization technique was then utilized to optimize Wire-EDM process parameters for achieving maximum MRR and minimum SR simultaneously.


In this work, central composite design(CCD) and desirability approach of Response surface methodology (RSM) has been used for optimization of biodiesel yield produced from mixture of animal waste fat oil and used cooking oil (AWO) in the ratio of 1:1through alkaline transesterification process. In this work, methanol quantity, reaction time and sodium hydroxide concentration are selected as input parameters and yield selected as response. The combined effect of methanol quantity, reaction time and sodium hydroxide concentration were investigated and optimized by using RSM. The second order model is generated to predict yield as a function of methanol quantity, reaction time and sodium hydroxide concentration. A statistical model predicted the maximum yield of 96.9779% at 35ml methanol quantity (% v/v of oil), 75 min. reaction time and 0.6g (% wt./v of oil) of sodium hydroxide. Experimentally, the maximum yield of 97% was obtained at the above optimized input parameters. The variation of 0.02% was observed between experimental and predicted values. In this work, an attempt has also made to use desirability approach of RSM to optimize the input parameters to predict maximum yield. Desirability approach predicts maximum yield (97.075%) at CH3OH (35.832% vol. /vol. of oil), NaOH (0.604 % wt./vol. of oil) and reaction time (79.054min.) was found for the AWO.


Author(s):  
Sanjeev Kumar ◽  
T.P. Singh ◽  
B.L. Sethi

Author(s):  
Arvind Kumar Dixit ◽  
Richa Awasthi

Titanium aluminide reinforced aluminium based metal matrix nano composite was prepared by stir casting route. Experiments were conducted with Cu electrode using L9 orthogonal array based on the Taguchi method. Discharge current (Lv), Pulse on time (Ton) and Flushing pressure (FP) are selected to calculate Metal removal rate (MRR), Tool wear rate (TWR) and Surface roughness (SR) based on Taguchi's parameter design. Moreover, the signal-to-noise ratios associated with the observed values in the experiments were determined using MINITAB software for MRR, TWR and SR. PCR – TOPSIS method is used to optimize Taguchi's multi response. Optimum parameter setting is found at Discharge current (Lv) 10 A, Pulse on time (Ton) 150 µs and Flushing pressure (FP) 1 kg/cm2.


Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 160 ◽  
Author(s):  
Dennis Asante-Sackey ◽  
Sudesh Rathilal ◽  
Lingham V. Pillay ◽  
Emmanuel Kweinor Tetteh

An ion exchange dialysis (IED) is used in the recovery of aluminium from residue. In this paper, the face-centred central composite design (FC-CCD) of the response surface methodology (RSM) and desirability approach is used for experimental design, modelling and process optimization of a counter flow IED system. The feed concentration, feed flowrate, sweep flowrate and sweep concentration were selected as the process variables, with the Al transport across a Nafion 117 membrane as the target response. A total of 30 experimental runs were conducted with six centre points. The response obtained was analysed by analysis of variance (ANOVA) and fitted to a second-order polynomial model using multiple regression analysis. The actual R2 and standard deviation of the model are 0.9548 and 0.2932, respectively. Depending on the time zone of reference (24 h or 32 h), the highest enrichment of >1.50 was achieved. The designed variables were numerically optimized by applying the desirability function to achieve the maximum Al transport. The optimised condition values were found to be a feed concentration of 1600 ppm, feed flowrate of 61.76%, sweep flowrate of 37.50% and sweep concentration of 0.75 N for the 80% target response at 32 h. Overall, the model can be used to effectively predict Al recovery using the designed system.


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