Faculty Publications
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Item Generation of microholes on GFRP composite using ES-µ-ECDM system(Elsevier Ltd, 2022) Bhargav, K.V.J.; Shanthan, P.; Balaji, P.S.; Sahu, R.K.; Sahoo, S.K.Microfeatures fabrication on FRPs is very essential nowadays because of its growing demand in various industries like aerospace, automobile, space, marine, etc. Glass fiber reinforced plastic (GFRP) composite is one among the FRPs that has many potential applications with extraordinary physical, chemical and mechanical properties. Generation of microholes on GFRP composite has gained its pace in recent years because of its applications in circuit boards and filters in biomedical applications. This study focuses on the generation of microholes in GFRP composite using an in-house developed electrolyte-sonicated micro-electrochemical discharge machining (ES-µ-ECDM) system. The process parameters voltage (V), concentration (wt%), and feed rate (µm/s) are selected at three levels for performing experiments using FCC-RSM modeling. The machining responses material removal rate (MRR) and overcut (OC) are analyzed. A RSM-based regression model is developed, and a multi-objective optimization using the MOJAYA algorithm is employed to obtain a set of non-dominated Pareto optimal solutions. The Pareto optimal solution set showed a feed rate of 5 µm/s should be employed for better MRR and OC. The SEM micrographs have shown a feed rate of 5 µm/s produced smooth surfaces at voltages and concentrations less than 55 V and 17.5 wt%, respectively. © 2022 Elsevier LtdItem Exemplary approach using tool rotation-assisted µ-ECDM for CFRP composites machining(Taylor and Francis Ltd., 2023) Bhargav, K.V.J.; Balaji, P.S.; Sahu, R.K.; Katiyar, J.K.Carbon fiber-reinforced polymer (CFRP) composites are an advanced composite material class due to their remarkable properties such as high load-carrying capacity and low density. CFRP composites have enormous applications in aerospace, biomedical, automobile, etc. Machining the CFRP composite is need of the day, but issues like delamination, fiber pullouts, workpiece damage, etc. have made it difficult. These limitations can be surpassed by the micro-electrochemical corona discharge machining (µ-ECDM) process. Although the process has showcased high process capability and great versatility in machining conducting and non-conducting materials, the process has limitations in machining holes deeper than 300 µm because of insufficient electrolyte supply at the machining zone. Aiding assistance to the process can overcome the limitation by enhancing electrolyte availability. Therefore, an experimental analysis is carried out by generating through holes on the CFRP composite using a tailor-made rotating tool-assisted micro-electrochemical corona discharge machining (RT-µ-ECDM) system. The process parameters, voltage, concentration, duty factor, and tool rotation rate are taken at three levels. The materials removal rate and overcut as machining characteristics were analyzed. The multi-response optimization using JAYA algorithm and R-method is used to obtain the optimal process parameters. The experimental investigation suggests RT-µ-ECDM system can machine through holes on CFRP composite. © 2022 Taylor & Francis.Item Micromachining of borosilicate glass using an electrolyte-sonicated-µ-ECDM system(Taylor and Francis Ltd., 2023) Bhargav, K.V.J.; Balaji, P.S.; Sahu, R.K.Glass has become an integral part of today’s world. This is because of its wide range of applications owing to its various potential properties. Though it has enormous applications, processing or machining glass is a challenging task. The present study focuses on the generation of microholes on borosilicate glass (thickness: 1000 µm) using an in-house developed in-situ electrolyte-sonicated (ES)-micro electrochemical discharge machining (µ-ECDM), i.e. ES-µ-ECDM system. The experiments revealed that the sonication of electrolytes had increased the electrolyte flushing, which enables the basic µ-ECDM process to push its limits and machine the materials beyond 300 µm (hydrodynamic regime). The process parameters selected for the experimentation are voltage, concentration, and duty factor with sonication of electrolyte at 36 kHz frequency throughout the experiments. Material removal rate (MRR) and overcut (OC) are identified as the machining characteristics in this study. To acquire enhanced machining characteristics, the process parameters are further optimized using the MOJAYA algorithm in conjunction with the R-method which is a multi-attribute decision-making method (MADM). The detailed experimentation revealed that using electrolyte sonication through-holes was achieved at a higher level of parameter settings. © 2022 Taylor & Francis.Item Micromachining of Al7075 alloy using an in-situ ultrasonicated µ-ECDM system(Taylor and Francis Ltd., 2023) Bhargav, K.V.J.; Pyla, K.R.; Balaji, P.S.; Sahu, R.K.Al7075 is a lightweight metal alloy essentially used in various engineering sectors possessing applications in aerospace, military, missile, etc. Miniaturized machining operations have placed a great deal of pressure on the conventional machining capabilities of Al7075 alloys as they possess certain challenges due to their ductile and unique adhesive nature, which must be overcome. The present study focuses on generating through-holes on Al7075 alloy using an electrolyte ultrasonication-assisted µ-ECDM system. The FCC-RSM factorial-based design is chosen at three levels to carry out experimentation with process characteristics voltage (V), concentration (wt%), and duty factor (%DF). The material removal rate (MRR), top hole overcut (TOC), bottom hole overcut (BOC), and circularity (CIR) are the machining responses. JAYA algorithm, a multi-objective optimization is performed, and optimal process parameters are obtained using the R method. Further, RSM based desirability approach is also used to obtain optimal process parameters and compared them with results obtained from R-method and found to be relatively close. © 2023 Taylor & Francis.Item Generation of microchannels on PMMA using an in-house fabricated μ-ECDM system(Walter de Gruyter GmbH, 2023) Bhargav, K.V.J.; Balaji, P.S.; Sahu, R.K.Electrochemical corona discharge micromachining (μ-ECDM) is a newly advented, advanced hybrid machining process capable of machining non-conducting and conducting materials. In this article, Polymethyl methacrylate (PMMA), a non-conducting material, often used in microfluidic applications, is machined to generate microchannels. The process parameters chosen for machining are voltage, duty factor, and concentration. The process parameters are chosen at three levels, and their effect on machining characteristics such as material removal rate and surface roughness are detailed in this paper. Optimization is carried out for individual response using the signal to noise ratio optimization technique for maximizing material removal rate and minimizing surface roughness. © 2023 Walter de Gruyter GmbH, Berlin/Boston.