Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
Browse
15 results
Search Results
Item Preparation and evaluation of mechanical properties of Al-6061 reinforced with graphite and fly ash of seed husk (Honge) particulate metal matrix composite(Institution of Engineering and Technology jbristow@theiet.org, 2013) Edrard, C.; Kapilan, N.; Herbert, M.A.The aim of this work is to study the mechanical properties of Aluminium alloy Metal Matrix Composites (MMCs) as they are gaining wide spread acceptance for automobile, industrial, and aerospace applications because of their low density, high strength and good structural rigidity. In the present work an attempt has been made to synthesize Al- 6061 with Graphite and fly ash of seed husk (Honge seeds) particulate metal matrix composites by using stir casting technique. The addition level of reinforcement is being varied from 0,4,6,8wt%. Preheated particle reinforcements are added to Al 6061 Alloy to improve wettability and distribution. Microstructural analysis was carried out for the above prepared composites by taking specimens from central portion of the casting to ensure homogeneous distribution of particles. Micro-hardness, tensile properties of the composites were studied as per the ASTM (E8M) standards. Microstructural characterization revealed fairly uniform distribution in the matrix. The Micro-Vickers hardness of the composite was found to decrease with increase in filler content in the composite. The density of both theoretically and experimentally of FA is higher then Gr. The tensile strength of the composites was found to increase confirming the dispersed graphite and fly-ash in Al-6061 alloy contributed in enhancing the tensile strength and wear resistance too of the composites.Item Effect of centrifugal and gravity casting technique over metallographic and mechanical properties of spheroidal graphite iron(2013) Desai Gowda, H.S.; Mukunda, P.G.; Herbert, M.A.The mechanical properties of cast iron depend on the graphite morphology and characteristics of metallic matrix. In spheroidal graphite iron these properties are affected by the nodule count, nodule percentage, nodularity, nodules per square mm, nodule types and size distribution. In this work an attempt is made to study of the effect of centrifugal and gravity casting process on the morphology and mechanical properties. A comparison of microstructure and mechanical properties of specimens of the cast are studied. It has been observed that the centrifugal effect produces an increase in rupture strain but hardness is unaffected. In microstructure it has been observed that the centrifugal effect produces an increase in the number of bigger nodules and decrease in the number of smaller nodules and an increase of nodules per square mm. It has no effect on nodularity percentage. The centrifugal casting process produces better mechanical properties.Item Experimental study on linear displacement measurement sensor using RGB color variation technique with PID controller(Institute of Electrical and Electronics Engineers Inc., 2017) Murthy, A.; Rao, S.S.; Herbert, M.A.; Karanth P, P.This study is based on experimental approach to linear displacement measurement using RGB color coding algorithm. This system is based on the auto-calibration procedure which can be implemented in a circuit, based on the temporal changes in the intensity of light, with the help of a light dependent resistor (LDR). The system consists of two LDRs and an LED placed on one side and an RGB color coded reflective paper on the opposite side. PIC microcontroller is used for powering the LED, processing of data for feedback control and to display the output on an LCD. LDR1 reading is used for displaying the relative linear distance, by mapping the voltage as a function of distance. This reading is used as a feedback to a PID controller to correct for the deviation in the measurement. Extensive experimental observations are conducted to analyze the reliability of the results in accordance to the wavelength of light reflected, the signal voltage and power output of the system. Investigation of the optimum positioning of the LED and the reflective RGB color coded paper is performed by repeatability analysis and hysteresis effects. Furthermore, the efficiency of the system is increased by implementing a PID controller upon investigating the different controller design, viz. P, PI and PID. A high resolution of 0.1 [mm] is obtained for such a simple and economical system, thereby making it highly efficient, in both minute measurements as well as over the entire bandwidth range of the visible light spectrum. © 2017 IEEE.Item Influence of modified cutting inserts in machining of Ti-6Al-4V alloy using PCD insert(Elsevier Ltd, 2018) Rao, R.; Rao, S.S.; Herbert, M.A.In modern manufacturing industries, the emerging needs of modern metal cutting operation are to increase the tool life with good surface finish and higher material removal rate. These objectives can be achieved by reducing the cutting temperature at the cutting zones with proper cooling system. The present work involves the experimental study of MQL application through the micro-holes drilled on the cutting inserts during turning of Ti-6Al-4V alloy using PCD inserts. The effect of the micropool lubrication of cutting insert on cutting temperature, surface roughness and tool wear have been compared with normal insert machining. It has been observed that in micropool lubrication method, cutting temperature was reduced by 30-33% over normal insert machining. Micropool lubrication reduced the flank wear to a maximum of about 20-30% over normal insert machining. The experimental result of the current research work indicates considerable benefits of surface roughness and tool wear through reduction in cutting temperature due to the perforation of the cutting insert. © 2018 Elsevier Ltd. All rights reserved.Item Active Upper Arm Exoskeleton - Design and Kinematic Analysis(Institute of Electrical and Electronics Engineers Inc., 2019) Santra, P.; Mukhopadhyay, A.; Debnath, B.; Herbert, M.A.; Bhaumik, S.The authors present a design of an exoskeleton with 6 active degrees of freedom (DOF) and 5 passive DOFs for rehabilitation of stroke survivors. Emphasis has been laid on making the model light weight and more ergonomic. Thus, concentration is mainly on 3D modeling of that device so that the mechatronic approach is compatible with human hand. The main choice of material for fabrication has been Nylon 6/10, owing to its lightweight and durable properties. The model was developed completely by the use of Computer Aided Design (CAD) and Computer Aided Engineering (CAE). Our model focuses on proposing a new actuation principle for better development of ergonomic shoulder design by incorporation of compliant passive springs and one passive revolute joint. Joints of the exoskeleton have been taken as simple revolute, possessing desired motion limits. Also forward kinematics has been established and the general workspace of the model has been developed. © 2019 IEEE.Item Studies on the Effect of Process Parameters in Turning of Ti-6Al-4V Alloy Using Topsis(IOP Publishing Ltd, 2019) Rao, C.M.; Rao, S.S.; Herbert, M.A.Optimization of process parameters in turning process is the fundamental machining operation which leads to better machining performance. This study has applied Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) method to obtain the optimum process parameters in turning of Ti-6Al-4V alloy using Polycrystalline Diamond (PCD) cutting tool insert. The process parameters chosen for optimization were cutting velocity, feed rate and depth of cut. The objective is to minimize cutting temperature, tool wear, and surface roughness. TOPSIS is employed to analyze the input parameters on output performance characteristics. Nine experiments were conducted under MQL (Minimum Quantity Lubrication) environment based on an L9 orthogonal array, respectively. The optimization results indicate turning Ti-6Al-4V alloy at cutting velocity of 150 m/min, the feed rate of 0.5 mm/rev and depth of cut of 0.5 mm as optimum parameters obtained by TOPSIS technique. From the Analysis of variance (ANOVA), it was identified that depth of cut parameter is the most influencing process parameter on turning performance characteristics. © Published under licence by IOP Publishing Ltd.Item Study on Mechanical and microstructural characteristics of Friction Stir Welded Aluminium Matrix composite(Elsevier Ltd, 2020) Prabhu B, S.R.B.; Shettigar, A.K.; Herbert, M.A.; Rao, S.S.Aluminium matrix composites (AMCs) are part of advanced materials, possesses capabilities to serve the present industrial needs due to its superior properties. Potential use of these AMCs in a particular application is limited if it is unable to join properly. In the present study AMCs are prepared by stir casting technique and welded by friction stir welding (FSW) process. FSW is performed using combined threaded and square profiled pin (CTSP). Further the welded joints were examined for microstructure and joint strength. Tensile test indicates that joint efficiency of 97 % is obtained, normal to the weld direction. Compare to the base material the nugget zone of weld region shows higher hardness. The microstructural study reveals that uniform distribution of finer grains are visible at nugget zone. © 2018 Elsevier Ltd.Item Taguchi method of optimization of process variables for ultimate tensile strength of friction stir welded joint of Al-Ce-Si-Mg aluminium alloy plates(Elsevier Ltd, 2021) D’Souza, A.D.; Rao, S.S.; Herbert, M.A.A novel method of welding known as friction stir welding or FSW has found wide applications in metal joining industries now a days. There are various process input variables which affect the output quality characteristic or response of the weld joint produced. Speed of tool rotation, tool feed and tool pin contour are important input process variables and ultimate tensile stress (UTS) of the FSW joint is the output response considered in this research. The Taguchi method of Design of Experiments type optimization was used to find the level and contribution of each of these input process variables on output quality characteristic of the FSW butt joint produced on plates of Al-Ce-Si-Mg aluminium alloy material. Taguchi L9 orthogonal array type design was utilized to bring down the number of experiments from 27 to 9 for a 3 factor, 3 levels each, analysis. The results of Taguchi analysis indicated that the speed of tool rotation at 1200 rpm, tool feed at 15 mm/min and triangular shape pin tool gave the peak output UTS. The ANOVA tests demonstrated that the contribution percentage of the tool pin contour at 41%, speed of tool rotation at 29%, and tool feed at 22%, showing that the tool pin contour has maximum bearing on the output quality characteristics, i.e., UTS of the FSW joint. The optimum UTS predicted by the Taguchi analysis was 88.29 MPa, whereas the confirmation experiments gave a result of 80.54 MPa, which was well inside the confidence interval predicted by the Taguchi design. © 2021 Elsevier Ltd. All rights reserved.Item Experimental investigation of joint properties of friction stir welded aluminium matrix composite(Elsevier Ltd, 2021) Prabhu B, S.R.; Shettigar, A.; Herbert, M.A.; Rao, S.S.The present study is focused on welding of particulate aluminium matrix composites using friction stir welding process and investigating the influence of various process variables on the joint properties. The microstructural study and mechanical behaviors such as tensile strength and hardness of the weld zone were measured. Microstructural studies showed that process variables play pivotal role in refinement of grains. Compared to the top of the weld region, smaller grains were formed at the bottom due to variation in the heating effect. Measurement of the tensile strength and hardness of the weld zone, indicated that process variables plays important role in controlling the joint properties. Beyond the optimum range of process variables, the joint strength of welded part deteriorates due to the insufficient stirring and lack of plasticization leads to defect formation. Joint welded with traverse speed of 100 mm/min and revolution speed of 1200 rpm exhibited better mechanical properties. © 2021 Elsevier Ltd. All rights reserved.Item Process parameter optimization for ultimate tensile strength of friction stir welded joint of Al-10Mg-8Ce-3.5Si aluminium alloy plates using Taguchi technique(Elsevier Ltd, 2022) D’Souza, A.D.; Rao, S.S.; Herbert, M.A.The Friction stir welding (FSW) process has become a popular method of joining metals, due to its clean and efficient nature of producing welds. The input process parameters: the tool rotation speed, tool feed and tool pin shape are the deciding parameters for an optimum output quality characteristic, the Ultimate tensile stress (UTS) of the weld joint. Here in this research, the Taguchi full factorial design technique is discussed for maximizing the UTS of the weld joint formed in Al-10Mg-8Ce-3.5Si aluminium alloy plates. The ANOVA of means and Signal to Noise ratios for UTS was used to assess the influence of each of the input process parameters on output UTS. The main effect plots of the ANOVA results demonstrated that, the tool rotation speed at level 2 or 1000 rpm, the tool feed at level 3 or 20 mm/min and tool pin shape at level 1 or triangular cross section, gave the optimum results for output UTS. The ANOVA for UTS also showed the percentage contribution of input process parameters; the shape of tool pin as 60.06%, the tool feed as 15.42% and shape of tool pin as 2.41%. The UTS value predicted by the Taguchi analysis was at 108.47 MPa which was in good agreement with the experimentally obtained value of 106.84 MPa. A nonlinear regression equation was developed by correlating the input process parameters, which could be used to predict the optimum UTS results. © 2022 Elsevier Ltd. All rights reserved.