Faculty Publications
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Item Recent advances in aluminizing of mild steel plates(Elsevier, 2024) Huilgol, P.; Bhat Panemangalore, D.; Bhat, K.U.; Bharadishettar, N.Aluminizing of steels is a surface modification method wherein the steel surface is subjected to thermo-chemical diffusion treatment at temperatures in the range of 700–1000°C. During the treatment, aluminium will diffuse into the surface and subsurface of the steel substrate, producing various aluminide phases. By controlling the process parameters, the type and quantity of aluminide phases can be controlled. The aluminides present beneficial properties, like increased strength and hardness, oxidation resistance, erosion resistance, abrasion resistance, etc. Hence, they are a better candidate material for designing the materials against scratch, erosion, fatigue, wear, oxidation, and corrosion. Many processing routes are available for aluminizing of steels and this entry reviews recent developments in the aluminising of mild steels. © 2024 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.Item Hot corrosion studies on as-received and HVOF sprayed Al2O 3+CoCrAlTaY on Ti-31 alloy in salt environment(Elsevier Ltd, 2013) Jegadeeswaran, N.; Ramesh, M.R.; Bhat, K.U.The present investigation is on the High Velocity Oxy-Fuel coating of Ti-31 alloy using fused, blended powder, Al2O3+CoCrAlTaY. Hot corrosion experiments were done on the coated and uncoated Ti-31 under a salt environment of 50% Na2SO4 and 50%V2O 5 at 800°C. Thermogravimetric cycles of 1 hour heating and 20 minute cooling was followed for hot corrosion study. After each cycle weight measurement was carried out. After hot corrosion, the samples were characterized using XRD and SEM/EDS. It was observed that the coated sample is more resistant to hot corrosion than uncoated sample. XRD and SEM analysis indicated that the surface is rich in oxides. Gravimetric analysis indicated that the sample weight gain was following a parabolic relationship with time. A damage mechanism is discussed for the hot corrosion damage of the samples. Presence of high level of chromium in HVOF sprayed coating imparts improved hot corrosion resistance at 800°C, in a molten salt environment of Na2SO4 + V 2O5. © 2013 The Authors. Published by Elsevier Ltd.Item On line monitoring of quality of friction surfacing(Trans Tech Publications, 2014) Janakiraman, S.; Bhat, K.U.Quality of deposition during friction surfacing depends on a number of parameters. With instrumentation many of these parameters can be observed in real time. Monitoring of these parameters allows one to incorporate necessary corrections, whenever, that parameters goes out of the safe domain. Present investigation aims at the potential of monitoring some of these parameters online and the quality of the deposition. It is observed that spindle speed and torque are not effective parameters whereas monitoring material consumption or height of the consumable friction tool is very much useful in monitoring the quality of the deposition. © (2014) Trans Tech Publications, Switzerland.Item Effect of nickel sulphate to hypophosphite ratio on the electroless deposition of Ni-P coatings on aluminium(Trans Tech Publications, 2014) Jayalakshmi, M.; Bhat, K.U.Electroless Ni-P alloy was deposited on commercial pure aluminium with different nickel source-reducing species ratios. Deposition time was fixed as two hours. The deposits were characterised for changes in morphology and crystallinity. It was observed that increase in nickel source to reducing species ratio produced a deposit with reduced mean nodule size. Also, nodule size distribution was narrow. Deposits with increased ratio showed higher levels of crystallinity. © (2014) Trans Tech Publications, Switzerland.Item Flexible binder free functionalized carbon nanotube electrodes for ultracapacitor(SPIE spie@spie.org, 2014) Badekai Ramachandra, B.R.; Aravinda, L.S.; Bhat, K.U.The Flexible supercapacitor electrode material was prepared by simple spray coating technique. This will provide a greener alternative for the fabrication of binder free composite electrode for supercapacitor applications. A symmetric double layer super capacitor stack was fabricated by using flexible electrodes. The investigation of the capacitance property of the fabricated super capacitor stack was investigated using cyclic voltammetry, chronopotentiometry and electrical impedance spectroscopy studies. The flexible electrode material shows a specific capacitance of 50 Fg-1 with good cyclibility. © 2014 SPIE.Item Hydrazine sensing properties of microwave synthesized graphene/ZnO composites(American Institute of Physics Inc. subs@aip.org, 2016) Moolayadukkam, M.; Nagaraja, H.S.; Bhat, K.U.This paper reports the synthesis of graphene/ ZnO nanocomposite using microwave method and its application in sensing of hydrazine. The morphological characteristics of the samples are studied using Scanning Electron Microscope (SEM). The formation of the composite is further confirmed by the X-ray Diffraction (XRD). Energy Dispersive X-ray Analysis (EDAX) shows the presence of carbon indicating the presence of graphene. The hydrazine sensing property of the electrode is studied using cyclic voltammometry (CV) and Chronoamperometry (CA) studeis. © 2016 Author(s).Item Crystallite size measurement and micro-strain analysis of electrodeposited copper thin film using Williamson-Hall method(American Institute of Physics Inc. subs@aip.org, 2016) Augustin, A.; Rajendra Udupa, K.; Bhat, K.U.The improvement in hydrophilicity of copper coating on aluminium for better antimicrobial activity can be achieved by increase in surface energy. The surface energy depends on the micro-strain of the coating. Micro-strain in the coatingincreases with reduction in crystallite size. In this investigation, the crystallite size in the electrodeposited copper coating was varied by varying deposition current density. Crystallite size and micro-strain in the coating were estimated using Williamson-Hall method. Values of crystallite sizes using TEM micrographs were in agreement with that using Williamson-Hall method. Also, presence of nano-Twins in the coating contributed for micro-strain in copper coating. © 2016 Author(s).Item Solubility Limits of Ceria-Zirconia-Lanthana Solid-Solutions(Elsevier Ltd, 2017) Abbas, Z.; Surendran, M.; Anjana, P.A.; Jidev, P.K.; Harshini, H.; Sudhakar Naidu, N.; Anandhan, S.; Bhat, K.U.; Bhaskar Babu, G.U.; Prasad Dasari, H.P.We demonstrate, the solubility limits of Ceria-Zirconia-Lanthana (CZLa) solid-solutions with the increase in heat-treatment temperature from 600°C to 1300°C. CZLa nano-crystalline samples were successfully synthesized by EDTA-Citrate complex method and were characterized by Raman Spectroscopy (RS) and Transmission Electron Microscopy (TEM) analysis. With an increase in temperature, it is noticed that the solubility limit is decreased in CZLa system. At 600°C, a very good solubility is observed in CZLa system and is confirmed from RS analysis. At higher heat-treatment temperatures (1000 and 1300°C), with an increase in La content, Zr precipitated in the CZLa system and is confirmed from RS analysis. The reason for such kind of behavior in this CZLa system is clearly explained in this work. © 2017 Elsevier Ltd.Item Hot-dip Aluminizing of Low Carbon Steel in Al & Al-5wt % Cr Baths(Elsevier Ltd, 2018) Huilgol, P.; Bhat, K.U.; Udupa, K.R.Hot dip aluminizing of low carbon steel is carried out in pure aluminium bath and Al-5wt% Cr bath. The coating is characterized by scanning electron microscopy and chemical composition of the coating is analysed by EDS (energy dispersive spectroscopy) attached to SEM. The coating consists of three regions, viz., outer aluminium topcoat, intermediate Fe-Al intermetallics layer and the base alloy. The intermetallics layer consists of FeAl3 and Fe2Al5 phases. Fe2Al5 is the major phase in the intermetallics layer. The growth kinetics of intermetallics layer is parabolic in nature implying that it is diffusion controlled. Addition of chromium forms Al7Cr dispersed intermetallics phases in the aluminium topcoat. Addition of chromium has no influence on the morphology of the intermetallics layer. Scratch resistance of the coating is carried out to evaluate the scratch hardness of the coating. Chromium addition improves scratch resistance of the coating. © 2018 Elsevier Ltd.Item Purification of Silver Nanowires Synthesised by Polyol Method(Elsevier Ltd, 2018) Prabukumar, C.; Bhat, K.U.The mesh-based silver nanowires (Ag NWs) films are considered to be a good alternative to high-cost, brittle ITO as a transparent conductive electrode (TCE) for the sustainable flexible electronic devices. The polyol synthesis method is the common method to synthesis Ag NWs wherein Ag particles are also produced as a by-product. The present work used decantation combined with solvent-aid precipitation approach to remove silver particles from the Ag NWs suspension to produce quality Ag NWs based TCE. The synthesised and purified products were characterized by using Scanning electron microscopy, UV-Visible spectroscopy and X-ray diffractometry. This method proved to be a simpler and more effective one compared to filtration and centrifugation method as it yields more NWs against the particles. © 2018 Elsevier Ltd.