Faculty Publications
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Item Multi-objective Optimization of FSW Process Variables of Aluminium Matrix Composites Using Taguchi-Based Grey Relational Analysis(Springer Nature, 2019) Prabhu B, S.R.B.; Shettigar, A.K.; Herbert, M.A.; Rao, S.S.Successful joining of aluminium alloys using friction stir welding (FSW) opens a new window research in extending this technique to join aluminium matrix composites (AMCs). Current research is focused on optimization of process variables for multiple responses simultaneously. Experiments were performed using tool pin profile, rotational speed (RS) and welding speed (WS) as ideal process variables for multi-objective optimization in FSW of AMCs. Tensile strength, macro-hardness and elongation are considered as multi-response behaviour. Grey relational grade for the chosen multiple responses are obtained using grey analysis. Analysis of variance was utilized to understand the influence of process variables on the grey relational grade. Analysis reveals that RS and WS were the most influencing process variables on the output responses. Confirmation experiments were performed at optimized process variables to validate the present study. Predicted values were in good agreement with the experimental results. © 2019, Springer Nature Singapore Pte Ltd.Item Influence of Process Variables on the Ultimate Tensile Strength of Friction Stir Welded AA6061 Matrix Composite(Springer Nature, 2021) Shettigar, A.; Prabhu B, S.R.; Herbert, M.A.; Rao, S.S.The present study is focused on the application of the friction stir welding process (FSW) to weld aluminium matrix composites (AMCs). Joints are formed by varying FSW process variables such as tool revolving speed (TRS), tool traverse speed (TTS) and the tool pin geometry (TPG). Influence of these parameters on the ultimate tensile strength (UTS) of the joints is investigated. Process variable optimization is done using Taguchi L18 orthogonal array design. Optimum process variables are determined and confirmed by confirmation tests based on the analysis of variance. © 2021, Springer Nature Singapore Pte Ltd.Item Mechanical Properties and Microstructural Characteristics of Friction Stir Welded Aluminium Matrix Composite(Springer Nature, 2021) Subramanya, B.; Shettigar, A.; Herbert, M.A.; Rao, S.S.Nowadays, friction stir welding process appears a promising technique to weld difficult materials by conventional welding techniques. Present study aims to analyse the significance of process variables on the mechanical behaviour of aluminium matrix composite joined by friction stir welding (FSW) technique. FSW is carried out at different welding conditions using conventional threaded cylindrical tool (TC). Microstructural study indicates several tiny reinforced particles are uniformly distributed in the nugget region. Recrystallization and grin refinement are observed in the weld area. Nugget region exhibits higher hardness compared to the base material. Joint efficiency of up to 89% is obtained for the FS-welded composite. The fracture surface reveals that the matrix undergoes a ductile fracture whereas reinforced particles exhibit brittle fracture. © 2021, Springer Nature Singapore Pte Ltd.Item An Industry 4.0 Approach: Data Acquisition and Machine Monitoring for Welding Machines(Springer Nature, 2024) Narendra Reddy, T.N.; Ponnappa, N.P.; Prasad, P.; Vinod, P.; Herbert, M.A.; Rao, S.S.The research introduces an innovative application of Industry 4.0 principles in welding by employing IIoTbased performance monitoring equipment. One the important aspect of Industry 4.0 adaption is understanding the requirement from the customer and develop/ provide the acceptable solution to them is crucial. An attempt has been made to develop a solution which can be used for any kind of welding machines including legacy welding machines. The developed solution delivers real-time updates on shop floor welding processes with the help of Operational Technology (OT) and Information technology (IT) with the help of hall effect sensors and voltage transducers by connecting them to the Programmable logic controller (PLC). Additionally, it facilitates real-time feedback, alerts, and report generation. The study comprehensively assesses the effectiveness and production capacity of an industrial welding system, presenting a detailed design overview and practical demonstration. Potential enhancements, such as integrating machine learning, emphasizing remote monitoring, evaluating energy efficiency, addressing cybersecurity, and assessing scalability, are explored. The research includes a cost–benefit analysis for the shopfloor and provides insights into the real-world effectiveness of IIoT-based welding performance monitoring in industrial contexts. The developed solution has been tested, validated, and deployed in one of the welding industries, and it has helped in real-time monitoring, scheduling the work and data analytics. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.Item Correlational Study of Ultimate Tensile Stress and Hardness of Friction Stir-Welded Al–Ce–Si–Mg Aluminum Alloys(Springer Nature, 2024) D’Souza, A.D.; Herbert, M.A.; Rao, S.S.In this research article, an analysis of correlation between mechanical properties of aluminum alloy such as ultimate tensile stress and Vickers hardness is carried out. Research analysis shows that hardness and UTS have a direct relationship. Tool rotation speed also directly impacts hardness and UTS values by controlling the amount of heat generated and hence extent of plasticization and grain refinement in the region of the weld. According to the research results, the plane surfaces of the square profiled pin of the tool aid in introducing a pulsing effect, which contributes to improved strength of weld connection. When compared to other tool profiles, a higher dynamic-to-static ratio attained with the triangular profiled pin tool results in greater material sweeping. As a result, the highest UTS and hardness values were obtained for welding connections created with the triangular profile pin tool. The study shows that the various input process parameters pertaining to tool revolving velocity, welding velocity, and tool-pin profile have a similar relationship on both hardness and ultimate tensile strength of weldment connection obtained with friction stir weld process. Hence, a similar trend or correlation has been observed in the variation of hardness and UTS. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.Item A pressured steam JET approach to tool wear minimization in cutting of metal matrix composites(Trans Tech Publications Ltd, 2007) Anjaiah, D.; Shetty, R.; Pai B, R.; Vijaya, M.V.; Rao, S.S.Metal matrix composites (MMCs) have been found to possess tremendous prospective engineering applications that require materials offering a combination of lightweight with considerably enhanced mechanical and physical properties. However, the applications of MMCs are limited by their poor machinability which is a result of their highly abrasive nature that causes excessive wear to the cutting tools. In this study, an investigation into the mechanism of the tool wear in cutting of MMCs is carried out. It is found that during cutting of an MMC, the tool cutting edge will impact on the reinforcement particles. The impacted particles will then either be dislodged from the matrix, doing no harm to the tool, or be embedded into the matrix, ploughing on the tool flank and causing excessive tool flank wear. According to this tool wear mechanism, a pressured steam jet approach is developed for the minimization of the tool wear by preventing the impacted reinforcement particles from being embedded in the workpiece matrix. Experimental tests for cutting of SiC-aluminum MMC using cubic boron nitride (KB-90) and polycrystalline diamond (KP-300) tool inserts with the aid of the pressured steam jet are conducted. The results show that from full factorial design of experiments the effect of the pressured steam jet plays a significant role on the tool wear followed by tool inserts and depth of cut. The working mechanism of the pressured steam jet method and the experimental testing results are discussed in detail.Item Inference of optimal speed for sound centrifugal casting of Al-12Si alloys(2011) Rao, S.; Mukunda, P.G.; Rao, S.S.; Sudhakar, K.G.True centrifugal casting is a standard casting technique for the manufacture of hollow, intricate and sound castings without the use of cores. The molten metal or alloy poured into the rotating mold forms a hollow casting as the centrifugal forces lift the liquid along the mold inner surface. When a mold is rotated at low and very high speeds defects are found in the final castings. Obtaining the critical speed for sound castings should not be a matter of guess or based on experience. The defects in the casting are mainly due to the behavior of the molten metal during the teeming and solidification process. Motion of molten metal at various speeds and its effect during casting are addressed in this paper. Eutectic Al-12Si alloy is taken as an experiment fluid and its performance during various rotational speeds is discussed.Item Prediction of surface finish and optimization of machining parameters in turning(2012) Prasad, D.; Krishna, P.; Rao, S.S.Surface roughness plays a crucial role in the functional capacity of machined parts. In this work, experiments were carried out on a conventional lathe for different cutting parameters namely feed, spindle speed, depth of cut and tool nose radius according to Taguchi Design of Experiments. Radial acceleration readings were taken with an accelerometer. Optimum cutting parameters and their level of significance were found using Taguchi analysis (ANOVA). Regression analysis was carried out to identify whether the experimental roughness values have fitness characteristic with the process parameters. Recurrence Plots (RP) were obtained using the sensor signals which determine surface roughness qualitatively and Recurrence Quantification Analysis (RQA) technique was used to quantify the RP obtained. Surface finish was predicted using a feed forward back propagation neural network with RQA parameters, cutting parameters and acceleration data as inputs to the network. The validity and reliability of the methods were verified experimentally. © (2012) Trans Tech Publications.Item Future applications of carbon nanotube reinforced functionally graded composite materials(2012) Udupa, G.; Rao, S.S.; Gangadharan, K.V.Future applications demand materials having extraordinary mechanical, thermal and chemical properties which must sustain the different environment conditions and in the same time available easily at reasonable prices. The carbon nanotubes(CNT) reinforced functionally graded composite materials(FGCM) is expected to be the new generation material having a wide range of unexplored potential applications in various technological areas such as aerospace, defence, energy, automobile, medicine, structural and chemical industry. They can be used as gas adsorbents, templates, actuators, catalyst supports, probes, chemical sensors, nanopipes, nano-reactors etc. This paper explores in detail the different possibilities of application of CNT reinforced functionally graded composites and manufacturing techniques, which raise the awareness on the promise of nanotechnology and the potential impact on aerospace industry as well as on other areas. © 2012 Pillay Engineering College.Item Investigation on microstructure and mechanical properties of Friction Stir Welded AA6061-4.5Cu-10SiC composite(Institute of Physics Publishing michael.roberts@iop.org, 2016) Herbert, M.; Shettigar, A.K.; Nigalye, A.V.; Rao, S.S.The application of Metal Matrix Composites (MMCs) is restricted by the availability of properly developed fabrication methods. The main challenge here is the fabrication and welding of MMCs in a cost effective way. In the present study, synthesis of AA6061-4.5%Cu- 10%SiC composite was done by stir casting method. The joining of MMCs was performed by Friction Stir Welding (FSW) using a combination of square and threaded profile pin tool (CSTPP). Further, the welded composite was evaluated for microstructure and joint properties. The microstructural characterization showed uniform distribution of refined fine grains and numerous small particles at nugget zone. The hardness at the stir zone is higher than that of the base material. The tensile test revealed 96% joint efficiency in transverse direction. © Published under licence by IOP Publishing Ltd.