Faculty Publications
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Publications by NITK Faculty
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Item Steam as coolant and lubricant in turning of metal matrix composites(2008) Shetty, R.; Pai B, R.B.; Kamath, V.; Rao, S.S.Green cutting has become focus of attention in ecological and environmental protection. Steam is cheap, pollution-free and eco-friendly, and then is a good and economical coolant and lubricant. Steam generator and steam feeding system were developed to generate and feed steam. Comparative experiments were carried out in cutting AA6061-15 vol.% SiC (25 ?m particle size), with cubic boron nitride (CBN) insert KB-90 grade under the conditions of compressed air, oil water emulsion, steam as coolant and lubricant, and dry cutting, respectively. The experimental results show that, with steam as coolant and lubricant, gradual reduction in the cutting force, friction coefficient, surface roughness and cutting temperature values were observed. Further, there was reduction in built up edge formation. It is proved that use of water steam as coolant and lubricant is environmentally friendly. © 2008 Zhejiang University and Springer-Verlag GmbH.Item Taguchi's technique in machining of metal matrix composites(Brazilian Society of Mechanical Sciences and Engineering, 2009) Shetty, R.; Pai B, R.B.; Rao, S.S.; Nayak, R.This paper presents the study on Taguchi's optimization methodology, which is applied to optimize cutting parameters in turning of age hardened Al6061-15% vol. SiC 25 ?m particle size metal matrix composites with Cubic boron nitride inserts (CBN) KB-90 grade using steam as cutting fluid. Analysis of variance (ANOVA) is used to study the effect of process parameters on the machining process. This procedure eliminates the need for repeated experiments, time and conserves the material by the conventional procedure. The turning parameters evaluated are speed, feed, depth of cut, nozzle diameter and steam pressure. A series of experiments are conducted using PSG A141 lathe (2.2 KW) to relate the cutting parameters on surface roughness, tool wear, cutting force, feed force, and thrust force. The measured results were collected and analyzed with the help of the commercial software package MINITAB15. As well, an orthogonal array, signal-to-noise ratio is employed to analyze the influence of these parameters. The method could be useful in predicting surface roughness, tool wear, cutting force, feed force and thrust force as a function of cutting parameters. From the analysis using Taguchi's method, results indicate that among the all-significant parameters, steam pressure is the most significant parameter. © 2009 by ABCM.Item Application of response surface methodology on surface roughness in grinding of aerospace materials (6061Al-15Vol%SiC25P)(2010) Dayananda Pai, D.; Rao, S.S.; Shetty, R.; Nayak, R.In this paper, the effects and the optimization of machining parameters on surface roughness in the grinding of 6061Al-SiC25P (MMCs) specimen are investigated. In the grinding process, a machining parameter, such as hardness of the specimen, flow rate of the coolant and depth of cut while machining were chosen for evaluation by the response surface methodology. By response surface methodology, a complete realization of the process parameters and their effects were achieved. The variation of surface roughness with machining parameters was mathematically modeled using response surface methodology. Finally, experimentation was carried out to identify the effectiveness of the proposed method. © 2006-2010 Asian Research Publishing Network (ARPN). All rights reserved.Item Analysis of surface roughness and hardness in titanium alloy machining with polycrystalline diamond tool under different lubricating modes(Universidade Federal de Sao Carlos, 2014) Revankar, G.D.; Shetty, R.; Rao, S.S.; Gaitonde, V.N.The present work deals with the investigation on machining of difficult-to-machine material titanium alloy (Ti-6Al-4V) using poly crystalline diamond (PCD) tool under different coolant strategies, namely dry, flooded and MQL. Taguchi technique has been employed and the optimization results indicated that MQL lubricating mode with cutting speed of 150 m/min, feed rate of 0.15 mm/rev, nose radius of 0.6 mm and 0.25 mm depth of cut is necessary to minimize surface roughness and dry mode with cutting speed of 150 m/min, feed rate of 0.15 mm/rev, nose radius of 0.6 mm and 0.75 mm depth of cut is necessary to maximize surface hardness. The results indicate the substantial benefit of the minimum quantity of lubrication (MQL) and justify PCD inserts to be the most functionally satisfactory commercially available cutting tool material for machining titanium alloys for better surface finish and hardness.Item Selection of optimal process parameters in ball burnishing of titanium alloy(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2014) Revankar, G.D.; Shetty, R.; Rao, S.S.; Gaitonde, V.N.The current study deals with the analysis and optimization of the ball burnishing process of titanium alloy (Ti-6Al-4V). The Taguchi method was employed to determine the best combination of ball burnishing process parameters - such as burnishing speed, burnishing feed, burnishing force and number of passes - to minimize surface roughness and maximize hardness. The dry burnishing experiments were planned as per L9 orthogonal array (OA,) and signal-to-noise (S/N) ratio was applied to measure the proposed performance characteristics. Analysis of means (ANOM) and analysis of variance (ANOVA) were carried out to evaluate the optimal levels and to obtain the level of importance of the burnishing parameters, respectively. Validation tests with optimal levels of parameters were performed to illustrate the effectiveness of Taguchi optimization. The optimization results revealed that burnishing feed and burnishing force are the significant parameters for minimizing the surface roughness, whereas number of passes and burnishing force play important roles in maximizing the hardness. © 2014 Taylor & Francis Group, LLC.Item Analysis of surface roughness and hardness in ball burnishing of titanium alloy(Elsevier B.V., 2014) Revankar, G.D.; Shetty, R.; Rao, S.S.; Gaitonde, V.N.Ball burnishing is a popular post-machining metal finishing operation. An attempt has been made in this paper to optimize the process parameters during burnishing of titanium alloy (Ti-6Al-4V). Ball burnishing process parameters such as burnishing speed, burnishing feed, burnishing force and number of passes were considered to minimize the surface roughness and maximize the hardness. The lubricated ball burnishing experiments were planned as per L25 orthogonal array and signal to noise (S/N) ratio was applied to measure the proposed performance characteristics. The validation tests with the optimal levels of parameters were performed to illustrate the effectiveness of Taguchi optimization. The optimization results revealed that burnishing feed and burnishing speed are the significant parameters for minimizing the surface roughness, whereas burnishing force and number of passes play important roles in maximizing the hardness. The optimization results showed greater improvements in surface finish (77%) and hardness (17%) when compared to pre-machined surfaces. © 2014 Elsevier Ltd. All rights reserved.Item Wear resistance enhancement of titanium alloy (Ti-6Al-4V) by ball burnishing process(Elsevier Editora Ltda, 2017) Revankar, G.D.; Shetty, R.; Rao, S.; Gaitonde, V.N.The objective of the research was to improve the wear resistance of titanium alloys by ball burnishing process. Burnishing process parameters such as burnishing speed, burnishing feed, burnishing force and number of pass were considered to minimize the specific wear rate and coefficient of friction. Taguchi optimization results revealed that burnishing force and number of pass were the significant parameters for minimizing the specific wear rate, whereas the burnishing feed and speed play important roles in minimizing the coefficient of friction. After burnishing surface microhardness increased from 340 to 405 Hv, surface roughness decreased from 0.45 to 0.12 ?m and compressive residual stress were generated immediately below the burnished surface. The optimization results showed that specific wear rate decreased by 52%, whereas coefficient of friction was reduced by 64% as compared to the turned surface. The results confirm that, an improvement in the wear resistance of Ti-6Al-4V alloy has been achieved by the process of ball burnishing. © 2016 Brazilian Metallurgical, Materials and Mining Association.