scholarly journals Relevance Vector Machine Based Analyses of MRR and SR of Electrodischarge Machining Designed by Response Surface Methodology

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Kanhu Charan Nayak ◽  
Rajesh Kumar Tripathy ◽  
Sudha Rani Panda

Relevance vector machine is found to be one of the best predictive models in the area of pattern recognition and machine learning. The important performance parameters such as the material removal rate (MRR) and surface roughness (SR) are influenced by various machining parameters, namely, discharge current (Ip), pulse on time (Ton), and duty cycle (tau) in the electrodischarge machining process (EDM). In this communication, the MRR and SR of EN19 tool steel have been predicted using RVM model and the analysis of variance (ANOVA) results were performed by implementing response surface methodology (RSM). The number of input parameters used for the RVM model is discharge current (Ip), pulse on time (Ton), and duty cycle (tau). At the output, the corresponding model predicts both MRR and SR. The performance of the model is determined by regression test error which can be obtained by comparing both predicted MRR and SR from model and experimental data is designed using central composite design (CCD) based RSM. Our result shows that the regression error is minimized by using cubic kernel function based RVM model and the discharge current is found to be one of the most significant machining parameters for MRR and SR from ANOVA.

2016 ◽  
Vol 79 (1) ◽  
Author(s):  
Abdul Azeez Abdu Aliyu ◽  
Jafri Mohd Rohani ◽  
Ahmad Majdi Abdul Rani ◽  
Hamidon Musa

In recent years, researchers have demonstrated increases interest in studies involving silicon carbide (SiC) materials due to several industrial applications. Extreme hardness and high brittleness properties of SiC make the machining of such material very difficult, time consuming and costly. Electrical discharge machining (EDM) has been regarded as the most viable method for the machining of SiC. The mechanism of EDM process is complex. Researchers have acknowledged a challenge in generating a model that accurately describes the correlation between the input parameters and the responses. This paper reports the study on parametric optimization of siliconized silicon carbide (SiSiC) for the following quality responses; material removal rate (MRR), tool wear ratio (TWR) and surface roughness (Ra). The experiments were planned using Face centered central composite design. The models which related MRR, TWR and Ra with the most significant factors such as discharge current (Ip), pulse-on time (Ton), and servo voltage (Sv) were developed. In order to develop, improve and optimize the models response surface methodology (RSM) was used. Non-linear models were proposed for MRR and Ra while linear model was proposed for TWR. The margin of error between predicted and experimental values of MRR, TWR and Ra are found within 6.7, 5.6 and 2.5% respectively. Thus, the excellent reproducibility of this experimental study is confirmed, and the models developed for MRR, TWR and Ra are justified to be valid by the confirmation tests.


2020 ◽  
Author(s):  
waqas javaid ◽  
Tauqeer Iqbal ◽  
Ammar ul Hassan

Abstract High surface quality, optimum Material Removal Rate (MRR) and Tool-Chip Interface temperature (T c ) have significant importance in machining process. Similarly, dimensional accuracy in machining process also relies heavily on machining parameters. In machining operations, there are a number of parameters which have direct or indirect effect on the Surface Roughness (Ra) and MRR of the product. The surface roughness and MRR in turning process are affected by spindle speed (SS), feed rate (FR) and depth of cut (DOC). The optimization of turning parameters will be very helpful in improving quality of manufacturing and machining cost. In order to have an improved product, extensive research has been carried out to optimize machining process. The current research is focused at Response Surface Methodology (RSM) of turning process of Aluminum alloy (BS-1474 2014 A) by using variable sets of machining parameters i.e., SS, FR and DOC with carbide tipped tool. Multiple experiments were performed on CNC Lathe machine by using different combinations of process parameters. Response surface methodology was applied to reach theoretical values of the responses parameters (i.e, Ra, MRR, T c ) and an agreement was observed between actual machining results and methodology values. Design Expert-7 was used as a statistical tool to come to a conclusion on whether achieved results are optimum for turning process or otherwise. For a close correlation, comparison between hypothetical and investigational data is also the part of this research. Significant agreement between theoretically optimized machining parameters and experimental data has been observed.


Author(s):  
M. Shunmugasundaram ◽  
A. Praveenkumar ◽  
L. Ponraj Sankar ◽  
S. Sivasankar

Hybrid metal matrix composite (HMMC) plays a crucial role in the development of better and advanced materials and in their automotive and aeronautical applications. In this investigation also HMMC is prepared using aluminium alloy, as matrix of material and boron nitrate and silicon carbide are chosen for reinforcing material and stir casting method is employed to prepare this new HMMC. The abrasive water jet method is employed for machining the developed HMMCs. The Taguchi approach with ANOVA approach is utilized for optimizing the independent machining parameters to exploit removal rate of material and surface roughness is to be minimized. The Taguchi based response surface methodology(RSM) is utilized for optimizing the machining parameters. Based on the response tables, the rate of feed and stand of distance are more influential parameters on the rate of removal of material and roughness of surface. The optimized machining parameters for improving the rate of removal the material are 100mm/min of FR, 1.5mm SOD and 600gm/min. The 125mm/min FR, 1.5mm SOD and 400gm/min AFR are the optimized machining parameters for minimizing the surface roughness.


Author(s):  
K. M. Patel ◽  
Pulak M. Pandey ◽  
P. Venkateswara Rao

Electric discharge machining (EDM) has been proven as an alternate process for machining complex and intricate shapes from the conductive ceramic composites. Al2O3 based electrodischarge machinable Al2O3–SiCw–TiC ceramic composite is a potential substitute for traditional materials due to their high hardness, excellent chemical, and mechanical stability under a broad range of temperature, and high specific stiffness. The right selection of the machining condition is the most important aspect to take into consideration in the EDM. The present work correlates the inter-relationships of various EDM machining parameters, namely, discharge current, pulse-on time, duty cycle, and gap voltage on the metal removal rate (MRR), electrode wear ratio (EWR), and surface roughness using the response surface methodology (RSM) while EDM of Al2O3–SiCw–TiC ceramic composite. Analysis of variance is used to study the significance of process variables on MRR, EWR, and surface roughness. The experimental results reveal that discharge current, pulse-on time, and duty cycle significantly affected MRR and EWR, while discharge current and pulse-on time affected the surface roughness. The validation of developed models shows that the MRR EWR and surface roughness of EDM of Al2O3–SiCw–TiC ceramic can be estimated with reasonable accuracy using the second-order models. Finally, trust-region method for nonlinear minimization is used to find the optimum levels of the parameters. The surface and subsurface damage have also been assessed and characterized using scanning electron microscopy. This study reveals that EDMed material unevenness increases with discharge current and pulse-on time.


Author(s):  
S. Chakraborty ◽  
S. Mitra ◽  
D. Bose

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.


2018 ◽  
Vol 49 (2) ◽  
pp. 62-81 ◽  
Author(s):  
Shailendra Kumar ◽  
Bhagat Singh

Tool chatter is an unavoidable phenomenon encountered in machining processes. Acquired raw chatter signals are contaminated with various types of ambient noises. Signal processing is an efficient technique to explore chatter as it eliminates unwanted background noise present in the raw signal. In this study, experimentally recorded raw chatter signals have been denoised using wavelet transform in order to eliminate the unwanted noise inclusions. Moreover, effect of machining parameters such as depth of cut ( d), feed rate ( f) and spindle speed ( N) on chatter severity and metal removal rate has been ascertained experimentally. Furthermore, in order to quantify the chatter severity, a new parameter called chatter index has been evaluated considering aforesaid denoised signals. A set of 15 experimental runs have been performed using Box–Behnken design of experiment. These experimental observations have been used to develop mathematical models for chatter index and metal removal rate considering response surface methodology. In order to check the statistical significance of control parameters, analysis of variance has been performed. Furthermore, more experiments are conducted and these results are compared with the theoretical ones in order to validate the developed response surface methodology model.


2018 ◽  
Vol 7 (3.1) ◽  
pp. 162 ◽  
Author(s):  
Ramanan. G ◽  
Rajesh Prabha.N ◽  
Diju Samuel.G ◽  
Jai Aultrin. K. S ◽  
M Ramachandran

This manuscript presents the influencing parameters of CNC turning conditions to get high removal rate and minimal response of surface roughness in turning of AA7075-TiC-MoS2 composite by response surface method. These composites are particularly suited for applications that require higher strength, dimensional stability and enhanced structural rigidity. Composite materials are engineered materials made from at least two or more constituent materials having different physical or chemical properties. In this work seventeen turning experiments were conducted using response surface methodology. The machining parameters cutting speed, feed rate, and depth of cut are varied with respect to different machining conditions for each run. The optimal parameters were predicted by RSM technique. Turning process is studied by response surface methodology design of experiment. The optimal parameters were predicted by RSM technique. The most influencing process parameter predicted from RSM techniques in cutting speed and depth of cut.   


Author(s):  
Mittal Sushil ◽  
Kumar Vinod ◽  
Kumar Harmesh

It is hard to finish small slots in composite materials which have wide applications nowadays in aerospace, automobile and medical. Abrasive flow machining is a process that is suitable for such type of operations. In this paper, by using abrasive flow machining, investigation of SiC Metal Matrix Composites (MMCs) with aluminum as base material has been done. Material removal rate and change in surface roughness (ΔRa) are taken as response parameters. Response surface methodology has been applied to find out the effect of input parameters like fluid pressure, percentage of oil in media, grit size, concentration of abrasives, workpiece material and number of cycles on response parameters. Box–Behnken design has been preferred. Response parameters have been optimized using the desirability approach in response surface methodology. The significance of different parameters is identified using analysis of variance. An optimum combination of parameters is designed for the process. Furthermore, specimens were examined and analyzed using scanning electron microscope and X-ray diffraction techniques.


2014 ◽  
Vol 592-594 ◽  
pp. 831-835 ◽  
Author(s):  
Vikram Singh ◽  
Sharad Kumar Pradhan

The objective of the present work is to investigate the effects of various WEDM process parameters like pulse on time, pulse off time, corner servo, flushing pressure, wire feed rate, wire tension, spark gap voltage and servo feed on the material removal rate (MRR) & Surface Roughness (SR) and to obtain the optimal settings of machining parameters at which the material removal rate (MRR) is maximum and the Surface Roughness (SR) is minimum in a range. In the present investigation, Inconel 825 specimen is machined by using brass wire as electrode and the response surface methodology (RSM) is for modeling a second-order response surface to estimate the optimum machining condition to produce the best possible response within the experimental constraints.


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