Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
Browse
9 results
Search Results
Item Influence of Multi Axial Forging (MAF) on Microstructure and Mechanical Properties of Cu-Ti Alloy(Elsevier Ltd, 2018) Ramesh, S.; Shivananda Nayaka, H.S.; Gopi, K.R.Multi axial forging (MAF) is one among the severe plastic deformation (SPD) processes, where large strains are imposed into the component. In the present work, as-received Cu-1.5%Ti alloy was subjected to MAF for 2 and 4 cycles at room temperature. Microstructure showed grain refinement after 2 and 4 cycles. Average grain size obtained for MAF processed samples after 2 and 4 cycles are 120 μm and 40 μm, respectively compared to initial grain size of 800 μm. The Mechanical properties were analyzed for as-received and MAF processed samples. Tensile test showed increased ultimate tensile strength (493 MPa) for MAF 4-cycle sample compared to as-received (191 MPa) condition with accumulated strain of 2.18 for 4 cycles. Increase in hardness was observed for MAF processed sample of 143 Hv for 4-cycle compared to as-received sample of 67 Hv. © 2018 Elsevier Ltd.Item Influence of cold rolling process on microstructure and mechanical properties of Cu-1.5%Ti alloy(American Institute of Physics Inc. subs@aip.org, 2018) Ramesh, S.; Shivananda Nayaka, H.S.; Anne, G.; Gopi, K.R.The effects of cold rolling on the microstructure evolution and mechanical properties of Cu-1.5%Ti alloy were investigated. The results showed that the tensile strength of the Cu-1.5%Ti alloy increased with an increase of rolling deformation at room temperature. Significant grain refinement took place during rolling process revealed in optical microstructure and transmission electron microscope analysis. XRD patterns revealed peaks indexed to Cu, Cu3-Ti2 and Cu4-Ti3 after 8-pass rolling process. Microhardness of the rolled Cu-1.5%Ti alloy layers increased incessantly with increase in the number of rolling passes. Tensile strength increased up to 294 MPa which was about 1.54 times higher than that of the cast Cu-1.5%Ti alloy. Fracture surfaces of the rolled Cu-1.5%Ti alloy revealed the dimples in the structure, which is an indication of ductile fracture. © 2018 Author(s).Item Development, Characterization, Mechanical and Corrosion Behaviour Investigation of Multi-direction Forged Mg–Zn Alloy(Springer International Publishing, 2019) Anne, G.; Ramesh, S.; Kumar, G.; Sahu, S.; Ramesh, M.R.; Shivananda Nayaka, H.; Arya, S.In the present study, homogenized Mg−4%Zn (wt%) alloy was exposed to multi-direction forging (MDF) at 280 °C up to 5 passes successfully. Microstructural evolution, mechanical properties and corrosion behavior of the MDF-processed Mg−4%Zn alloy was investigated using different characterization techniques. Five passes of MDF (cumulative strain, ΣΔε = 3.45) led to the formation of ultrafine grain structure (grain size ~2.3 μm) with high angle grain boundaries (HAGBs) and high dislocation density. Corresponding ultimate tensile strength (UTS) and microhardness were observed to be 228 MPa and 88 Hv. Potentiodynamic polarization test results exhibited higher corrosion resistance (0.38 mm/y) in comparison with that of homogenized condition (1.33 mm/y). © 2019, The Minerals, Metals & Materials Society.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.Item Physico-mechanical response of phenolic resin composites reinforced with jute and banana fibers(American Institute of Physics Inc. subs@aip.org, 2019) Prashanth, B.H.M.; Manjunath, T.S.; Shivakumar Gouda, P.S.S.; Sajjan, S.S.; Ramesh, S.In the present investigations, physico-mechanical properties of hybrid jute and banana fiber reinforced with the phenolic resin was made. The hybrid composites of jute and banana fiber were prepared with different weight ratios (40/20,20/40) incorporated with phenolic resin. These hybrid composites were manufactured using compression molding technique and evaluated mechanical properties such as tensile, impact strength, flexural strength,heat deflection temperature (HDT) analysis. It was observed that the weight ratios of jute and banana (40/20) gives the good mechanical and thermal properties as compare to the jute and banana (20/40). Further, fiber and matrix interfacial bonding of hybrid composite is observed using scanning electron microscope. © 2018 Author(s).Item Effect of Mechanical properties on Multi Axially Forged LM4 Aluminium Alloy(Elsevier Ltd, 2020) Sajjan, S.S.; Kulkarni, M.V.; Ramesh, S.; Sharath, P.C.; Kumar, V.; Rajole, S.Commercially available LM4 Aluminum alloy was subjected through Severe Plastic Deformation (SPD) method by Multi-Axial Forging Process (MAF) in ambient temperature. In this process, the material was processed successfully up to 5 Passes and mechanical properties such as tensile strength, compression strength and hardness of the as received and processed samples at ambient temperature were evaluated. The MAF processed sample result showed that the ultimate strength, percentage elongation and compression strength improved by 55 MPa, 3.75% and 162 MPa respectively as compared with the unprocessed sample. Hardness also increased with the increase in the number of passes. In the case of microstructure, grain size reduced from 110 μm to 8 μm after subjecting the sample to MAF. Fractography explains the nature of the fracture from received to processed samples by decreasing the size of the dimple and the type of fracture observed was ductile in nature. Improvement in strength and hardness of processed samples was observed due to the grain refinement and high amount of density dislocation in the material during MAF. © 2018 Elsevier Ltd.Item Microstructural and mechanical characterisation of Al-Zn-Mg-Cu alloy processed by multi-directional cryo-forging(Elsevier Ltd, 2021) Ramesh, S.; Anne, G.; Naik, G.M.; Jagadeesh, C.; Shivananda Nayaka, H.S.Aim of the present investigation is to study the microstructural and mechanical properties of Al-Zn-Mg-Cu alloy before and after multi-direction forging (MDF) at cryogenic condition up to 3 cycles. Microstructure evolution of specimen was examined using optical microscope and orientation imaging microscopy as well as X-ray diffraction. Mechanical properties were measured by tensile test and Vickers micro hardness. Microstructural investigation shows that after 3 cycle of MDF average grain size was reduced to 8 μm with low angle grain boundaries (LAGBs) and high dislocation density. Mechanical examination displays an improvement in hardness, yield strength and ultimate tensile strength is due to increases in grain boundaries and strain hardening effect. After 3 cycles of MDF process with cumulative strain ςΔϵ = 3.64 led to the formation of fine grain structure, and microhardness were observed to be 168 HV. © 2021 Elsevier Ltd. All rights reserved.Item A study on dimensional analysis modeling of crater size during wire electrical discharge turning process by using Buckingham Pi theorem(Elsevier Ltd, 2022) Naik, G.M.; Hipparagi, M.A.; Bellubbi, S.; Roy, A.; Anjan, B.N.; Ramesh, S.; Narendranath, S.The investigation on material removal by thermal erosion of discrete spark and vaporization in wire electrical discharge turning process was made to understand the crater size variation on turned components. In this study the modelling is done to establish the relationship between dependent and independent variables through Buckingham's Pi-theorem, to predict the variations of crater diameter depending on physical and thermal properties, subsequently the dimensional model was validated by conducting experiments on wire-electrical discharge turning process for two distinct density variant materials such as Aluminium 6061 and INCONEL 718 super alloys. The density, enthalpy of vaporization, radius of spark, specific heat and other quantities effect on crater diameter have been discussed in this research paper. © 2022