Conference Papers
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Item The influence of microwave sintering on the tribological performance of powder metallurgy based aluminum cenospheres composites(Trans Tech Publications Ltd ttp@transtec.ch, 2015) Ananda Kumar, M.G.; Seetharamu, S.; Sampath Kumaran, P.; Nayak, J.The Metal Matrix Composites (MMCs) especially Aluminum based systems have unique advantages of having superior mechanical, chemical and electrical properties, in addition to light weight and high stiffness. In this work, composites comprising of Aluminum with varied concentrations of Cenospheres as reinforcement was produced by Powder Metallurgy (PM) route. The densification of the composites was effected both by conventional and Microwave (MW) sintering techniques. The microstructures of the sintered samples were observed through scanning electron microscope (SEM) and phases by x ray diffraction technique (XRD), followed by evaluation of tribological parameter namely slide wear behavior and solid particle erosion resistance. The densities and the Brinell hardness values for the samples were also evaluated. The results showed that microwave sintered samples exhibited higher hardness, lower erosion and slide wear loss. © (2015) Trans Tech Publications, Switzerland.Item High temperature tribological studies of cold sprayed nickel based alloy on low carbon steels(Elsevier Ltd, 2019) Padmini, B.V.; Mathapati, M.; Niranjan, H.B.; Sampathkumaran, P.; Seetharamu, S.; Ramesh, M.R.; Mohan, N.The boiler steels of grades SAE213 T11 and T22, find extensive applications in heat exchanger tubes, paper and pulp, chemical industries and refineries. Further, these steels are also used in shafts, cylinders, bearings, and in automotive transmission parts and these aspects are less explored. They experience low wear life in specific components, both at room and slightly higher temperature regimes. In order to protect them from these damages, coatings are deployed involving many techniques like HVOF, Plasma spray, Cold spray etc. so that the life of the components get extended. In cold spray coatings, the powders are fed at very high impact velocities of up to 1200 m/s on the substrate and undergo plastic deformation during the impact. There is no oxidation of the powder takes place during the process, as the coating is done at very less temperature and this is one of the lead characteristic of cold spray technique. This particular work mainly focuses on evaluating the tribological behaviour of nickel based super alloy powder on T11 and T22 low alloy steels by cold spray method, using pin on disc machine both at room temperature as well as at 200, 300 and 400 °C. The associated tests such as hardness, porosity, and microstructure have been undertaken to support the wear data. The wear damage assessment has been carried out using scanning electron microscope to arrive at the mechanism and also to give credence to the wear data. © 2019 Elsevier Ltd.Item Study of dry sliding wear behavior of Al-Si-C FG alloy developed through directional solidification(American Institute of Physics Inc. subs@aip.org, 2019) Narayanappa, R.B.; Ramesh, M.R.; Kiran Aithal, K.A.; Shivakumar, V.K.; Manjunath, M.H.N.FGM is the materials in which the composition or micro structure or both are varied locally to attain a specific form of material properties from one position to the other extreme position. In this work Al-18wt% Si-2wt%C FG Alloy is processed through Directional solidification with base excitation. Molten metal when poured into the insulated mold, The copper chill which is placed at the bottom will extract heat so that solidification takes place linearly. When excitation is provided at the bottom the Silicon in the alloy will precipitate along the length of the specimen. Experimental investigation were carried out to study the wear behavior for the specimens processed with lateral vibrations and without lateral vibrations. © 2019 Author(s).Item Evolution of Tribological Properties of Cast Al–10Zn–2Mg Alloy Subjected to Severe Plastic Deformation(Springer Science and Business Media Deutschland GmbH, 2020) Manjunath, G.K.; Preetham Kumar, G.V.; Udaya Bhat, K.In the current investigation, tribological behaviour of the cast Al–10Zn–2Mg alloy processed by severe plastic deformation (SPD) technique was studied. In this work, one of the SPD techniques, equal channel angular pressing (ECAP) was adopted as a processing tool. ECAP was carried out in route BC and processing was attempted at the lowest temperature. After ECAP, grain structure of the material was refined and considerable improvement in the microhardness of the alloy was perceived. Mainly, wear resistance of the alloy material was enhanced with successive ECAP passes. Coefficient of friction of the alloy material was decreased with successive ECAP passes. Wear resistance of the alloy was decreased with a rise in the applied load and the sliding speed. Both at low and high load condition, abrasive wear was noticed in as-cast and homogenized specimens. Whereas in ECAPed specimens, in addition to abrasive wear, oxidation wear and adhesive wear were observed in low load and it changes to abrasive wear at high load. In the ECAPed specimens, at low load transfer of iron particles from the steel disc surface to the specimen surface was identified. © 2020, Springer Nature Singapore Pte Ltd.Item Effect of ECAP on sliding wear behaviour of Mg-Zn-Gd-Zr alloy(Elsevier Ltd, 2020) Patil, A.; Bontha, S.; Ramesh, M.R.Magnesium is a lightweight, recyclable, and biocompatible material. However, the extensive commercial use of Magnesium and its alloys is hindered by their poor wear behaviour and mechanical properties. Equal Channel Angular Pressing (ECAP) is a severe plastic deformation technique which improves the material properties through grain refinement. In the present study, wear behaviour of ECAP processed Mg-Zn-Gd-Zr alloy was investigated. ECAP process was carried out up to 3 passes at a temperature of 380 °C. Wear testing of as-cast and ECAP processed alloy were carried out using dry sliding wear method on a pin on disk tribometer by varying loads. The wear mechanism was analysed using Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). Average Coefficient of Friction (COF) increased after each pass of ECAP. Wear rate increased with the applied load. Despite severe plastic deformation, wear resistance of ECAP processed samples was found to be lower than that of as-cast samples at higher loads. Abrasive and oxidation wear mechanisms were found in both as-cast and ECAP processed samples. © 2019 Elsevier Ltd. All rights reserved.Item Effect of Ni and Sr additions on the microstructure, mechanical properties, and coefficient of thermal expansion of Al-23%Si alloy(Elsevier Ltd, 2021) Vijayan, V.; Ravi, M.; Prabhu, K.N.In this paper, the combined and individual effect of strontium (Sr) and nickel (Ni) additions on the microstructure and mechanical properties of hypereutectic Al-23Si alloy was studied using an optical microscopy, universal tensile testing machine and Brinell hardness tester. The wear properties and coefficient of thermal expansion of the melt treated samples were determined using pin on disc wear testing machine and linear expansion measurement unit respectively. The results indicate that the Ni additions significantly enhanced the mechanical properties of the alloy, whereas, presence of Sr was detrimental. It was observed that the improvement in mechanical properties due to Ni was primarily due to refinement and transformation of the star shaped primary silicon into polyhedral crystals. However, the addition of Sr, both as separate and when combined with Ni, transformed the primary silicon into a faceted crystal and hence decreased the mechanical property. Among all, the Ni melt treated alloy samples showed lowest wear rate and coefficient of thermal expansion. © 2021 Elsevier Ltd. All rights reserved.Item Characterization and sliding wear behavior of CoMoCrSi+Flyash composite cladding processed by microwave irradiation(Elsevier Ltd, 2021) Prasad, C.; Shashank Lingappa, M.; Joladarashi, S.; Ramesh, M.R.; Sachin, B.The present work deals with the development of CoMoCrSi+Flyash composite cladding on AISI 410 steel substrate using a domestic microwave oven with cladding process parameters of frequency 2.45GHz, with the power of 900W and processing time is 1800s. The developed clad is characterized by metallographic and mechanical properties. Further, the substrate and cladding samples are tested for high-temperature sliding wear behaviour using a pin on disc apparatus. The clad specimen exhibits partial melting of particles and observed uniformity in thickness. X-Ray Diffraction analysis shows the presence of Cr3C2, Co3Ti, TiC, SiC, and Mo3Si hard phases that are formed during the cladding process, while excellent metallurgical bonding can be observed which provides improved hardness. The addition of flyash into the cobalt-base matrix enhanced high-temperature strength results in better wear resistance due to the formation of oxide layers. © 2021 Elsevier Ltd. All rights reserved.Item Burnishing of ultra high molecular weight poly ethylene(Elsevier Ltd, 2021) Ashish, V.; Prasanna Kumar Reddy, S.; Kannan, C.; Oyyaravelu, R.; Balan, A.S.S.Ultra-high molecular weight polyethylene (UHMWPE) has been a choice for knee and hip implants since a very long time due to its outstanding tribological properties. UHMWPE has many applications other than biomedical implants like hydrodynamic bearings and marine applications. The main objective of this research work is to enhance the surface properties of UHMWPE and eventually increase its life expectancy for the implants. For this purpose, the UHMWPE sheet has been milled to give it a required shape and then ball burnished with a carbide ball of 6mm diameter under two different environments viz. room and cryogenic with three different burnishing strategic patterns. A constant load of 150N is maintained by the tool on UHMWPE sample with a burnishing feed of 4000mm/min along with a step over a distance of 0.06mm after every pass for three different carefully chosen burnishing patterns. To understand the wear behaviour of the material, wear test has been performed on reciprocating wear testing machine with a stainless-steel ball as a pin for 6500 cycles in the medium of Hank's balanced salt solution (HBSS) as a lubricating agent and to maintain the pH value which is same as in the human body. The lowest average surface roughness (Ra=0.52μm) is reported for the second strategy pattern which gets burnished under the cryogenic environment. This sample also exhibited better wear resistance than other samples burnished under different environments and using different strategic patterns. © 2021 Elsevier Ltd. All rights reserved.Item Sliding wear behaviour of Ni-5 %Al coating deposited by detonation spray on IN718(Elsevier Ltd, 2022) Purushotham, N.; Rajasekaran, B.; Parthasarathi, N.L.; Praveen, K.; Govindarajan, G.Ni-5 %Al metallic coating was deposited on Nickel-based superalloy (IN718) specimens using the detonation spray coating (DSC) method. Detonation spraying yielded coating with extreme chemical bond strength, hardness, and less porosity. The microstructure, microhardness, and room temperature pin-on-disc sliding wear behavior of the Ni-5 %Al coating and the as-received IN718 superalloy were evaluated. Sliding wear tests were done at room temperature (25 °C), under different loading conditions (6 N and 10 N), using an alumina (Al2O3) ball-on-disk tribometer and friction coefficients were measured. The study of worn surfaces conducted by SEM indicated that both Ni-5 %Al coating and the substrate suffered significant abrasive wear with occasional adhesion and spalling of the coating. The 3D topography of the wear track was examined by a 3D non-contact profilometer, which enabled the quantification of the wear. The friction coefficient values of the tests and the wear in terms of mass loss were in good correlation. © 2022Item Comparison of Wear Behaviour of Al–12.5Si Alloy Reinforced with ZrO2 Using Spray Deposition and Stir Casting Technique(Springer Science and Business Media Deutschland GmbH, 2023) Patil, I.S.; Rao, S.S.; Herbert, M.A.Aluminium silicon alloy materials are commonly used in aerospace and automotive engineering applications due to their enhanced stiffness, excellent wear resistance and lightweight. The measurement of wear properties for these combinations is very tangled. This can differ under different operating conditions. Dry sliding wear properties of Al–12.5Si with reinforced zirconium oxide matrix composite have been investigated using stir casting and spray deposition methods. The weight fraction of ZrO2 is 15%. The influence of applied nominal load (10 to 60 N) was investigated using the design of experiments. Wear properties of the hybrid composites were studied using pin-on-disc machine. The study found that the wear behaviour was improved by increasing the composition the zirconium oxide in alloy silicon matrix in both stir casting and spray forming techniques. The spray forming method showed lesser wear rate compared with stir casting method. Microstructure of the developed hybrid composites was analysed using scanning electron microscope (SEM). The developed hybrid composite samples have twice the improvement in wear resistance using spray deposition. The influence of reinforced zirconium oxide in aluminium silicon metal matrix on the wear properties using spray forming method is highlighted. This study shows that the wear resistance of the metal matrix composites can be improved by increasing the ZrO2 composition in aluminium silicon matrix. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.