Faculty Publications
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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 Effect of L/D ratio on Al-Si functionally graded material cast through centrifuge technique(2011) Kiran Aithal, A.S.; Narendranath; Desai, V.; Mukunda, P.G.Functionally Graded Material (FGM) is a class of material wherein the properties and structure are varied intentionally from one side to the other side of the specimen. This paper describes the effect of L/D (Length to Diameter) ratio of the cast on cast Al-Si FGM. The present study uses Al-17%wt Si to cast FGM's. The cast is evaluated for Microstructure and Hardness all along the length of the specimen. Three L/D ratios: 0.5, 1.0, 1.5 were cast using the Centrifuge Technique. The microstructures showed that enrichment of primary Si was largest in 1.5 ratio compared to other two. Hardness value of the cast at the upper and lower region were examined and found that gradient of hardness was more in 1.5 case. High volume percentage of primary Si was nearly 26% in the upper region and a hypoeutectic structure in the lower region. © (2011) Trans Tech Publications.Item Effect of process parameters on centrifugally cast Al-Si FGM(Minerals, Metals and Materials Society 184 Thorn Hill Road Warrendale PA 15086, 2013) Kiran Aithal, K.; Desai, V.; Narendranath, S.; Mukunda, P.G.Functionally Graded Materials (FGM) are such kind of materials wherein the properties and structure are varied from one end of the cast to the other intentionally. Centrifuge technique has been used in this study to produce Al-Si FGMs. Several process parameters determine the microstructure and the distribution of phases in the FG casting. These parameters include the size and initial concentration of alloying element, the centrifugal force, solidification rate, cooling rate. In this work an attempt has been made to produce FGMs using three different process variables such as mold temperature, melt temperature and mold rotational speed, their effect on the structure and properties. For this study Al-17wt%Si is used. From the results it is seen that for a particular melt and mold temperatures by increasing the mold rotation speed enhances the segregation of the Si particles at the one end of the casting. Similarly increasing mold or melt temperature only, increases the segregation.Item Studies on mechanical properties of porous anodic alumina membranes using microindentation test(American Institute of Physics Inc. subs@aip.org, 2015) Reddy, P.R.; Udayashankar, N.K.; Ajith, K.M.Porous anodic alumina (PAA) membranes were prepared using two-step self-organized anodization process carried out in 0.3 M oxalic acid at the temperature of about 5 o C. PAA membranes fabricated underconstant potential of 40 V gave optimum ordering of hexagonal pores. Microhardness of the prepared PAA membranes were studied using Vickers hardness test rig. It was observed that microhardness of prepared PAA membraneswere 2.20 GPa and 0.21 GPa for 100 g and1000 g loads respectively. © 2015 AIP Publishing LLC.Item Effect of process parameters on centrifugally cast Al-Si FGM(Springer International Publishing, 2016) Kiran Aithal, A.S.; Desai, V.; Narendranath, S.; Mukunda, P.G.Functionally Graded Materials (FGM) are such kind of materials wherein the properties and structure are varied from one end of the cast to the other intentionally. Centrifuge technique has been used in this study to produce Al-Si FGMs. Several process parameters determine the microstructure and the distribution of phases in the FG casting. These parameters include the size and initial concentration of alloying element, the centrifugal force, solidification rate, cooling rate. In this work an attempt has been made to produce FGMs using three different process variables such as mold temperature, melt temperature and mold rotational speed, their effect on the structure and properties. For this study Al-17wt%Si is used. From the results it is seen that for a particular melt and mold temperatures by increasing the mold rotation speed enhances the segregation of the Si particles at the one end of the casting. Similarly increasing mold or melt temperature only, increases the segregation. © The Minerals, Metals & Materials Society 2016.Item Effect of Lateral Vibrations during Directional solidification on Mechanical Properties of Al-18%wt Si Alloys(Elsevier Ltd, 2018) Ramesh Babu, N.; Ramesh, M.R.; Kiran Aithal, S.; Kotresh, K.Experimental Investigation on the effect of mold vibration on the mechanical properties of Al-18%WtSi have been carried out using Taguchi Technique, as the molten metal at 750°C is poured in to the insulated mold which is subjected to lateral vibrations, directional solidification takes place due to the presence of chill at the bottom which gives rise to a functionally graded alloy. Due to the excitation, silicon present in the molten metal precipitates along its length. The castings are prepared with varying chill materials and chill volumes without vibrations and with a vibrating frequency of 50Hz. ANOVA was applied to optimize the process parameters. Hardness and Tensile test for the samples was carried out. Improvements in the properties can be attributed to the grain refinement of the casting prepared under vibrations. © 2017 Elsevier Ltd.Item Effect of FSW on microstructure and hardness of AA6061/SiC/fly ash MMCs(Elsevier Ltd, 2018) Patil, S.; Narendranath, S.; Dupadu, D.In this study 6 mm thick plates of aluminum matrix composites (AMCs) composed of AA6061/SiC (10 Wt. %) /fly ash (7.5 Wt. %) were butt welded using friction stir welding (FSW. Microstructural characterization of weld joints was conducted by using optical microscopy (OM) and scanning electron microscopy (SEM). The microstructure of the weld revealed the presence of four different zones like nugget zone (NZ), thermo mechanically affected zone (TMAZ), heat affected zone (HAZ) and base metal (BM). Nugget zone reveals homogenous distribution of fly ash and SiC particles. Rotating effect of FSW tool results in breaking of some array of grains present in the parent AMCs. Needle like phases present in the parent AMCs eliminated successfully by the incorporation of fly ash particles. Higher hardness is observed in the nugget zone compared to other zones. © 2018 Elsevier Ltd. All rights reserved.Item Effect of SiC Reinforcement on Microstructure and Mechanical Properties of Aluminum Metal Matrix Composite(Institute of Physics Publishing helen.craven@iop.org, 2018) Ajagol, P.; Anjan, B.N.; Marigoudar, R.N.; Preetham Kumar, G.V.Aluminum reinforced with silicon carbide composites areextensively used in automobile industries and aerospaceowing to their favourable microstructure and improved mechanical behaviour with respect to pure aluminium but at a lower cost. Aluminium is remarkable for the low density and its ability to resist corrosion. The aim of present study istoevaluate the mechanical and microstructural properties of aluminum with silicon carbide (average particle size 30-45μm) reinforced in varying weight percentages (wt %) ranging from 0-15 wt% in a step of 5% each. Ultimate tensile strength, micro hardness and density of the fabricated composites were investigated as a function of varying SiC wt%. Microstructure analysis was carried out on casted composites using optical microscopy and scanning electron microscopy. From micrographs it is clear that fair distribution of reinforcing particles in the matrix and also observed some clustering and porosity in the cast material. Results revealed that, the addition of SiC reinforcement in the aluminum matrix increases the hardness and ultimate tensile strength gradually from 23 HV to 47 HV and 84 MPa to 130 MPa respectively. © Published under licence by IOP Publishing Ltd.Item Effect of multiaxial cryoforging on wear properties of cu-1.5%ti alloy(Trans Tech Publications Ltd ttp@transtec.ch, 2019) Ramesh, S.; Shivananda Nayaka, H.Copper-Titanium alloy was subjected to multi axial forging (MAF) at cryogenic temperature. Microstructure evolution was observed using optical microscope (OM). After 9 pass of MAF, grain size reduced to 2 µm. As number of MAF pass increases, hardness of the sample increased, due to strain hardening effect. Dry sliding wear test was performed on as-received and MAF processed samples using pin on disc wear machine. Tests were performed at 30 N and 40 N loads at 3 m/s constant speed and at 1000 m and 2000 m, sliding distance. Scanning Electron Microscope (SEM) and EDS was used to analyze the worn-out surface of the specimen. Wear mass loss of MAF processed sample reduced, with increased number of MAF passes. Frictional Coefficient (COF) reduced with increase in MAF passes and improved with increase in load, because of increase in contact area between sample and disc. © 2019 Trans Tech Publications Ltd, Switzerland.Item Evaluation of microstructure and mechanical properties of multi axial forged lm2 aluminum alloy(Trans Tech Publications Ltd ttp@transtec.ch, 2019) Sajjan, S.S.; Kulkarni, M.V.; Ramesh, S.; Sharath, P.C.; Sangamesh, R.; Kumar, A.; Rajesh, R.Light metal Al alloys are presently used in aerospace and industrial applications. Hence, in the present study choice of material will be LM2 aluminum alloy and processed by multi-axial forging (MAF) technique at ambient temperature for different number of passes with an equivalent strain of 0.18, 0.36 and 0.54. Microstructural analysis was carried out on unprocessed and processed samples with scanning electron microscopy (SEM). As the number of MAF pass increases the average grain size was reduced because of plastic deformation by plane strain condition. Mechanical properties like Vickers hardness (VHN), tensile and compression test were carried out. Ultimate tensile strength (UTS) was increased after each pass of MAF due to strain hardening effect. After 3 MAF passes the compression strength was reached to maximum of 495 MPa as compared to as received sample 315 MPa and hardness, increased to 81 VHN as compared to 55 VHN for the received samples. The fractography analysis was explained using SEM images. As the number of passes increases dimple size reduces as compared to as received samples and which will be revealing the ductile mode of fracture. © 2019 Trans Tech Publications Ltd, Switzerland.