Browsing by Author "Kumar, S.S.S."

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    Corrosion of ECAPed magnesium alloys and its background: A Review
    (Chulalognkorn University, 2019) Naik, G.M.; SannaYellappa, N.; Kumar, S.S.S.
    The aim of this review article is to provide a brief mechanistic overview of magnesium alloys, equal channel angular pressing and corrosion behavior of un-ECAPed and ECAPed Mg alloys. The considerate of the corrosion processes of ECAPed Mg alloys builds upon interpretation of the corrosion of fine-grain magnesium alloys. This provides an understanding of the effect of grain size on corrosion of Mg alloys. This deep understanding is essential as a foundation if we are to produce corrosion-resistant magnesium alloys. Considerable has previously been accomplished, but there is enormous scope for development. This present concise review can provide a foundation for further, much desirable research. © 2019 Chulalognkorn University.
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    Corrosion of ECAPed magnesium alloys and its background: A Review
    (Chulalognkorn University, 2019) Naik, G.M.; SannaYellappa, N.; Kumar, S.S.S.
    The aim of this review article is to provide a brief mechanistic overview of magnesium alloys, equal channel angular pressing and corrosion behavior of un-ECAPed and ECAPed Mg alloys. The considerate of the corrosion processes of ECAPed Mg alloys builds upon interpretation of the corrosion of fine-grain magnesium alloys. This provides an understanding of the effect of grain size on corrosion of Mg alloys. This deep understanding is essential as a foundation if we are to produce corrosion-resistant magnesium alloys. Considerable has previously been accomplished, but there is enormous scope for development. This present concise review can provide a foundation for further, much desirable research. © 2019 Chulalognkorn University.
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    Effect of ECAP Die Angles on Microstructure Mechanical Properties and Corrosion Behavior of AZ80 Mg Alloy
    (Springer New York LLC barbara.b.bertram@gsk.com, 2019) Naik, G.M.; Narendranath, S.; Kumar, S.S.S.
    In this article, the effect of channel angles on material properties was investigated during equal channel angular pressing of AZ80 magnesium alloy using processing route R at 325 °C processing temperature. Channel angles of 90° and 110° and common corner angle 30° have been considered for this study. It has been revealed that the channel angle has a significant influence on deformation homogeneity, microhardness, ultimate tensile strength, ductility and corrosion behavior of Mg alloys. Investigation with reference to as-received AZ80 Mg alloy indicates 18.47% improvement in UTS and 76.07% enhancement in ductility after processing through 3P-90° and 2P-110° ECAP, respectively. Also, the corrosion rate reduces to 89.47% after processing the sample with 3P-110° ECAP die. © 2019, ASM International.
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    Experimental and Computational Analysis of Bio-Inspired Winglets for Micro Air Vehicles
    (Isfahan University of Technology, 2021) Sathyabhama, A.; Rajiv, A.M.; Sandeep, I.S.; Kumar, S.S.S.; Akash, C.H.
    Micro Air Vehicles (MAVs) are increasingly being used for civil and military surveillance. As the surveillance requirements are increasing, improving the range of MAVs becomes imperative. The performance of MAVs can be improved if the induced drag due to wingtip vortices can be reduced. In the present study, we try to decrease the induced drag caused by the wingtip vortices, which makes up a major part of the total drag, by introducing a winglet. A unique yet simple design, which has not yet been studied thoroughly, is explored. Inspiration is taken from the feather structures of birds to design the proposed winglet. The performance of a fixed-wing MAV at a free stream velocity (U?) of 20 m/s is studied. Multiple winglet configurations are used to compare the results with the baseline wing. An incompressible, steady three-dimensional simulation is carried out using the k-ro SST turbulence model. The experimental studies carried out for the baseline wing matched well with those obtained from CFD. Since the numerical model is valid, only computational study is done for the modified wing. The stall angle of the baseline wing is around 26°. Numerical results show that when the proposed winglet is used, the stall angle for the wing is increased to around 32°. The use of the winglet did not produce a considerable advantage at the lower Angle of Attack (AOA), but at higher AOA, the lift coefficient (CL) was considerably higher. The overall drag coefficient (CD) was higher at lower AOA when the winglet is used. But at AOAs greater than 5°, the CD reduced. Other effects of the winglet are addressed in terms of improvement in Lift-to-Drag ratio (L/D) and reduction in vorticity. The effect of the location and number of the feathers was studied to come up with an optimum winglet configuration. The experiments were carried for the wing with optimum winglet configuration and the results agreed fairly with the numerical results. © 2021. All Rights Reserved.
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    Influence of ECAP processing routes on microstructure mechanical properties and corrosion behavior of AZ80Mg alloy
    (2019) Gajanan, M.N.; Narendranath, S.; Kumar, S.S.S.
    Wrought magnesium alloys are a potential material for automobile, aerospace, marine and electronics industries because of less density, higher specific strength, damping characteristics and electromagnetic shielding properties. In spite of this interest, Mg alloys have not been extensively utilized owing to their poor mechanical behavior and corrosion resistance in comparison to other lightweight materials. However, the literature clearly indicated that mechanical behavior and corrosion performance of Mg alloys can be improved through equal channel angular pressing method. Therefore, In this paper made an attempt to examine the influence of ECAP processing route Bc and R on microstructure, mechanical properties and corrosion performance of AZ80Mg alloy at 390�C isothermal processing temperature. The microstructural and morphology analysis is made through OM and SEM respectively. The electrochemical polarization experiments was conducted to investigate the corrosion resistance of AZ80 alloy after processing it through route Bc and R. Results revealed that a significant increase in tensile strength, % elongation and corrosion resistance can be attained depending on the selected ECAP processing route. � 2019 Author(s).
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    Influence of ECAP processing routes on microstructure mechanical properties and corrosion behavior of AZ80Mg alloy
    (American Institute of Physics Inc. subs@aip.org, 2019) Naik, G.M.; Narendranath, S.; Kumar, S.S.S.
    Wrought magnesium alloys are a potential material for automobile, aerospace, marine and electronics industries because of less density, higher specific strength, damping characteristics and electromagnetic shielding properties. In spite of this interest, Mg alloys have not been extensively utilized owing to their poor mechanical behavior and corrosion resistance in comparison to other lightweight materials. However, the literature clearly indicated that mechanical behavior and corrosion performance of Mg alloys can be improved through equal channel angular pressing method. Therefore, In this paper made an attempt to examine the influence of ECAP processing route Bc and R on microstructure, mechanical properties and corrosion performance of AZ80Mg alloy at 390°C isothermal processing temperature. The microstructural and morphology analysis is made through OM and SEM respectively. The electrochemical polarization experiments was conducted to investigate the corrosion resistance of AZ80 alloy after processing it through route Bc and R. Results revealed that a significant increase in tensile strength, % elongation and corrosion resistance can be attained depending on the selected ECAP processing route. © 2019 Author(s).