Multi-Response Optimization of Electrochemical Machining of Al-Si/B4C Composites Using RSM

Author(s):  
Sadineni Rama Rao ◽  
G. Padmanabhan

The present work reports the electrochemical machining (ECM) of the aluminium-silicon alloy/boron carbide (Al-Si /B4C) composites, fabricated by stir casting process with different weight % of B4C particles. The influence of four machining parameters including applied voltage, electrode feed rate, electrolyte concentration and percentage of reinforcement on the responses surface roughness (SR) and radial over cut (ROC) were investigated. The process parameters are optimized based on the response surface methodology (RSM) and the optimum values for minimizing surface roughness and radial over cut are voltage 15.25 V, feed rate 1.0 mm/min, electrolyte concentration 13.56g/lit and percentage of reinforcement 7.36 wt%. The quality of the machined surfaces is studied by using scanning electron microscopic (SEM) images. The surface plots are generated to study the effect of process parameters and their interaction on the surface roughness and radial over cut, for the machined Al-Si/B4C composites.

2013 ◽  
Vol 13 (1-2) ◽  
pp. 31-36
Author(s):  
Sadineni Rama Rao ◽  
G. Padmanabhan

AbstractElectrochemical machining (ECM) is increasing its importance in machining of metal matrix composites (MMC) due to some specific advantages which can be exploited during machining operation. In ECM the quality of the surface produced is also depends on the workpiece physical and electrical properties along with the process parameters like voltage, feed rate, electrolyte concentration, type of electrolyte, current, gap between electrodes etc. Therefore, in the present work the percentage of reinforcement of the particulates in the matrix is considered one of the process parameters along with the applied voltage, electrode feed rate and electrolyte concentration. A mathematical prediction model of the radial over cut (ROC) was developed using response surface methodology (RSM). The effects of electrochemical machining parameters on the Radial over cut were evaluated. The contour plots were drawn to study the effect of various process parameters and their interaction. In this work the predicted values and measured values are quite close to each other. Therefore, the developed model can be effectively used to predict the radial over cut on electrochemical machining of Al-B4C composites.


2019 ◽  
Vol 8 (4) ◽  
pp. 2933-2941

Electrochemical Machining process is one of the popular non-traditional machining processes which is used to machine materials such as super alloys, Ti-alloys, stainless steel etc. Its working principle is based upon Faraday law of electrolysis. The aim of the present work is to optimize the ECM process parameters with the combination of SS 316 (job material) and Copper electrode (tool material). To explore the effect of ECM process parameters such as electrolyte concentration, voltage and current, feed rate on MRR and surface finish (Ra) of the job, total 27 experiments were conducted as per experimental scheme. The results of these experiments revealed that increase in electrolyte concentration decrease the mrr and surface roughness initially increases then decreases. Further, increase in current increases mrr initially and then decreases, surface roughness also increases. It is also noticed that increase in Feed rate mrr decreases and then increases, also surface roughness decreases then increases. Through RSM analysis it is found that the optimum conditions for maximum MRR, and minimum Surface roughness (Ra) is electrolyte concentration 150gm/lit, Voltage 13.5 V & feed 0.8 mm/min. The findings are discussed in the light of previous researches and subsequently conclusions are drawn.


Author(s):  
Nguyen Thi Bich Nhung ◽  
Dao Thanh Liem ◽  
Truong Quoc Thanh

Based on the number of previous studies, this study aims to investigate the effects of process parameters of an Electrochemical Machining process, which are electrolyte concentration, the voltage applied to the machine, feed rate of the electrode, and Inter-Electrode Gap between tool and workpiece. Aluminum samples of 25 mm diameter x 25 mm height and 30mm diameter x 25mm height of the tool is made up of copper with a circular cross-section with 2 mm internal hole. The design of the system is based on the Taguchi method. Here, the signal-to-noise (S/N) model, the analysis of variance (ANOVA) and regression analyses are applied to determine optimal levels and to investigate the effects of these parameters on surface quality. Finally, the experiments that use the optimal levels of machining parameters are conducted to verify the effects of the process parameters on the surface quality of the products. The results pointed out a set of optimal parameters of the ECM process. The Inter-Electrode Gap between the tool and workpiece has extremely effected on these Material Removal rates and surface roughness. The Material Removal Rate increases with diseases in Inter-Electrode Gap, and Ra diseases with diseases in Inter-Electrode Gap. The experimental results show that maximum Material Removal Rate has obtained with electrolyte concentration at 100 g/l, feed rate at 0.0375 mm/min, the voltage at 15V, and Inter-Electrode Gap at 0.5mm. The minimum Ra has obtained with electrolyte concentration at 80 g/l, feed rate at 0.0468 mm/min, the voltage at 10V, and Inter-Electrode Gap at 0.5mm. This result has led to need studies on these parameters in Electrochemical Machining, which are improving productivities and surface roughness of the products.   


Author(s):  
Milan Kumar Das ◽  
Tapan Kumar Barman ◽  
Kaushik Kumar ◽  
Prasanta Sahoo

Weighted principal component analysis is used to predict the optimal machining parameters for EN 31 tool steel in electrochemical machining for minimum surface roughness and maximum material removal rate based on L27 Taguchi orthogonal design. For this, multi-response performance index is calculated to derive an equivalent single objective function and then Taguchi method is used to optimize the process parameters. The separable influence of individual machining parameters and the interaction between these parameters are also investigated by using analysis of variance (ANOVA). Results show that the main significant factor on MRR and surface roughness is electrolyte concentration. The effects of process parameters viz. electrolyte concentration, voltage, feed rate and inter-electrode gap on MRR and surface roughness are also investigated using 3D surface and contour plots. Finally, the surface morphology is studied with the help of scanning electron microscopy (SEM) images.


2017 ◽  
Vol 12 (4) ◽  
pp. 72-80 ◽  
Author(s):  
Abbas Fadhil Ibrahim

Electrochemical machining is one of the widely used non-conventional machining processes to machine complex and difficult shapes for electrically conducting materials, such as super alloys, Ti-alloys, alloy steel, tool steel and stainless steel.  Use of optimal ECM process conditions can significantly reduce the ECM operating, tooling, and maintenance cost and can produce components with higher accuracy. This paper studies the effect of process parameters on surface roughness (Ra) and material removal rate (MRR), and the optimization of process conditions in ECM. Experiments were conducted based on Taguchi’s L9 orthogonal array (OA) with three process parameters viz. current, electrolyte concentration, and inter-electrode gap. Signal-to-noise (S/N), the analysis of variance (ANOVA) was employed to find the optimal levels and to analyze the effect of electrochemical machining parameters on Ra and MRR. The surface roughness of the workpiece was decreased with the increase in current values and electrolyte concentration while causing an increase in material removal rate. The ability of the independent values to predict the dependent values (R2) were 87.5% and 96.3% for mean surface roughness and material removal rate, respectively.


2010 ◽  
Vol 126-128 ◽  
pp. 885-890
Author(s):  
K.P. Somashekhar ◽  
N. Ramachandran ◽  
Jose Mathew

This work is on the preparation of microelectrodes for μ-EDM operation using μ-WEDG process. Electrodes of Ø500 μm are fabricated with various discharge energy machining conditions. Effects of gap voltage, capacitance & feed rate on the surface finish of the electrodes and overcut of the thus produced micro holes are investigated. The profile of microelectrodes is measured using surface roughness tester with 2μm stylus interfaced with SURFPAK software. The study demonstrated that for brass electrodes an arithmetic average roughness value as low as 1.7μm and an overcut of 3 µm could be achieved. The significant machining parameters are found using ANOVA. Surface of the produced microelectrodes are examined using Scanning Electron Microscope. μ-WEDG process parameters could be adjusted to achieve good surface integrity on microelectrodes. Experimental results showed that the surface roughness of microelectrodes depended primarily on feed rate of the electrode. The observations showed the clear and quantitative correlation existing between the micrometer level surface quality and process parameters. The resulting microelectrodes are found to be of exceptionally high quality and could be used for μ- EDM operation on different types of work materials.


2021 ◽  
Vol 24 (1) ◽  
pp. 34-37
Author(s):  
T. Sathish ◽  
N. Sabarirajan

The airline sector mostly preferable material as aluminium and its alloy due to light weight and better resistance combatant for environmental factors. In this work mainly focusing to fabricate the aluminium matrix composites and reducing the surface roughness value of the specimen in the machining process. Initially the AA7175 with reinforcement of zirconium carbide (ZrC) particles are synthesized by the route of stir casting process, the stirring deed improve the material strength. The Design of experiments is involved to optimize the machining (CNC vertical milling) parameters such as Spindle rotational speed (2000 rpm, 2400 rpm and 2800 rpm), Machine feed rate (1000 mm/min, 1400 mm/min and 1800 mm/min) and depth of cut (0.3mm, 0.6 mm and 0.9 mm). The L 27 orthogonal array model is conducted to optimize the factors with the help of Minitab numerical analysis. This approach finds the optimal factors and reduces the surface roughness value, the microstructure examine is carried out and its image is translated to analyze the 3D profilometry technique.


Author(s):  
S Chandrasekhar ◽  
NBV Prasad

This article describes the multi-response optimization of electrochemical machining operating parameters such as voltage, concentration of the electrolyte, and current to maximize the rate of material removal in addition to minimize the over cut and delamination at the same time in micro-drilling of AA6061-TiB2 in situ composite. A novel Entropy–VIKOR method is applied to handle such mutually conflicting responses. The weight of each response is computed from the entropy method, and VIKOR method is used to rank the various levels of parameters. This method yields the combination of 2 mol of electrolyte concentration, 16 V of applied voltage, and 4 A of current as optimal parameters to minimize the over cut and delamination in addition to maximize the rate of material removal at the same time. This optimal process-governing parameters satisfied the conditions for compromising solution such as acceptable advantage and acceptable stability condition. The response graph illustrates that, of the parameters investigated, electrolyte concentration has the greatest effect on the VIKOR index, followed by applied voltage and current. Scanning electron microscopic analysis illustrates that the radius of the hole is equal throughout the periphery, except for one instance of micro-delamination.


2013 ◽  
Vol 13 (3) ◽  
pp. 145-153 ◽  
Author(s):  
Sadineni Rama Rao ◽  
G. Padmanabhan

AbstractThe present paper deals the application of Taguchi method with grey relational analysis to optimize the machining parameters with multiple responses in electrochemical machining (ECM) of Al/B4C metal matrix composites. Experiments were conducted on a Metatech ECM setup and L27 orthogonal array was chosen for the experiments. The electrochemical machining parameters namely applied voltage, feed rate, electrolyte concentration and reinforcement content were optimized based on multiple responses, i.e. material removal rate, surface roughness and radial over cut. The morphology of the machined surfaces was studied with scanning electron micrographs. The optimum machining parameters are calculated by using grey theory and results are compared with ANOVA. The results show that the feed rate and electrolyte concentration are the most significant parameters which affect the multiple machining responses simultaneously. Experimental results show that the responses in ECM can be improved effectively through this approach.


2018 ◽  
Vol 53 (20) ◽  
pp. 2909-2924 ◽  
Author(s):  
Ajit Dhanawade ◽  
Shailendra Kumar

Traditional machining of carbon epoxy composite material is difficult due to excessive tool wear, excessive stresses and heat generation, delamination, high surface waviness, etc. In the present paper, research work involved in the experimental study of abrasive water jet machining of carbon epoxy composite material is described. The aim of present work is to improve surface finish and studying defects in machined samples. Taguchi's orthogonal array approach is used to design experiments. Process parameters namely hydraulic pressure, traverse rate, stand-off distance and abrasive mass flow rate are considered for this study. Analysis of machined surfaces and kerf quality is carried out using scanning electron microscope to evaluate microscopic features. Further, the effect of machining parameters on surface roughness is investigated using analysis of variance approach. It is found that traverse rate and pressure are most significant parameters to control surface roughness. Optimization of process parameters is performed using grey relational analysis. Thereafter, confirmation tests are carried out to verify the improvement in the surface quality with optimum set of process parameters. It is found that surface finish of machined samples is improved by 10.75% with optimum levels of process parameters. Defects like delamination, fiber pull-out and abrasive embedment are also studied using SEM. It is observed that delamination and fiber pull-out are prominent in samples machined at low pressure and high traverse rate.


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