Conference Papers
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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 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 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.