Conference Papers

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Subject: search.filters.subject.Erosion

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    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.
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    Studies on the role of HVOF coatings to combat erosion in turbine alloys
    (Elsevier Ltd, 2018) Prasanna, N.D.; Siddaraju, C.; Shetty, G.; Ramesh, M.R.; Reddy, M.
    Erosive wear is caused by the action of sliding or impact of solids, liquids, gases or the combination of these. Solid particle erosion is an important material degradation mechanism encountered in a number of engineering systems such as gas turbine engines, thermal power plants, coal slurry pipe lines. Erosive action results from the impact of particulates, such as coal ash, dolomite and un-burnt carbon particles on the surface of turbine. Super alloys developed for high temperature applications suffer from the drawback that the strength and the erosion-corrosion resistance at high temperature exhibited are poor. To improve the resistance property, one way would be the use of coatings on the super alloy component. Coatings take care of the problems related to erosion whereas the super alloys take care of the requirement of strength at elevated temperature. Various coatings have been highly attractive; however, High Velocity Oxy-fuel (HVOF) process, a family of thermal spray techniques uses kinetic energy of the burnt gases to soften and to propel the spray powder producing dense very low porosity, good inter-particle cohesion and well bonded coatings. In the present study successful attempts have been made to spray Stellite-6, 10%Al2O3+90%CoCrAlTaY and 25%Cr3C2-20(Ni-Cr)+75%NiCrAlY on three kinds of turbine alloys, namely Ti-6Al-4V, Co-based super alloy (Super co 605) and Fe-based special steel (MDN121).Microstructure and mechanical properties of the coatings have been characterized. Erosion tests for different conditions using Air-jet erosion test rig for different impingement angles have been studied in detail. From these studies it is observed that satellite-6 coating exhibits lower erosive rate compared to other two coating materials. The morphology of the eroded surface shows craters, groove formation in the binder matrix and carbide pull-out as the existing erosion mechanism. Higher erosion loss is observed for Al2O3+CoCrAlTaY coating. © 2018 Elsevier Ltd.
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    Erosion and Accretion in the Netravati River Stretch: Spatiotemporal Analysis Using Geospatial Approach
    (Springer Science and Business Media Deutschland GmbH, 2024) Makhdumi, W.; Shwetha, H.R.; Dwarakish, G.S.
    Understanding erosion and accretion, which are critical geomorphic processes, is essential for effective river management and conservation. Erosion by removing soil and rock changes the river's shape, depth, and course. Accretion, conversely, involves the deposition and accumulation of sediment, shaping features like riverbanks and floodplains. Focused on a 30 km stretch of the Netravati River, in the southwestern region of India, this study used Survey of India toposheets and Landsat images to track changes over time (1973, 1998, 2022). The Normalised Difference Water Index (NDWI) and image classification were employed for the analysis which revealed notable spatiotemporal variations in these processes. From 1973 to 2022, the analysis estimated a total erosion of 510.43 hectares and an accretion of 317.71 hectares. The years 1973–1998 witnessed more accretion (417.6 hectares) than erosion (229.08 hectares). And, from 1998 to 2022, erosion dominated at 438.37 hectares, with only 56.97 hectares of accretion. These variations can be attributed to both natural processes and human interventions. Notably, the construction of a vented dam in 1993 at Thumbe, followed by the subsequent dam in 2016, 50 m downstream of the old dam, influenced the sediment dynamics and flow patterns in the Netravati River, potentially impacting erosion and accretion processes. This research adds to our understanding of erosion and sediment changes in the Netravati River over time. The dams and hydraulic structure upstream along with geospatial techniques offer researchers and river managers a unique opportunity to examine river shape impacts and thus develop sustainable strategies for river preservation. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.