Faculty Publications
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Item Development and properties evaluation of Mg-6% Zn/Al multilayered composites processed by accumulative roll bonding(Cambridge University Press, 2017) Anne, G.; Ramesh, M.R.; Shivananda Nayaka, H.; Arya, S.B.; Sahu, S.Accumulative roll bonding (ARB) process was used to develop Mg-6% Zn/Al and Mg-6% Zn/anodized-Al multilayered composites. Microstructural characterization was done using scanning electron microscopy, energy-dispersive X-ray spectroscopy, electron backscattered diffraction, and transmission electron microscopy. An average grain size measured in the roll-bonded layers of Al, anodized Al, and Mg-2% Zn was found to be 1.8 ?m, 1.6 ?m, and 0.6 ?m, respectively. Phases Al17Mg12, AlMg4Zn11, and Al2O3 after 5-pass of ARB were confirmed by X-ray diffraction analysis. The Mg-6% Zn/Al and Mg-6% Zn/anodized Al composites exhibited tensile strengths ?252 MPa and ?256 MPa, respectively, after a 5-pass ARB process. Hardness of the individual layers of composite increased linearly with an increase in the number of ARB passes. Fractographs of the multilayered composite illustrated the ductile failure in Al and anodized Al layers and transgranular brittle fracture in Mg-6% Zn layers. © Materials Research Society 2017.Item Elevated Temperature Solid Particle Erosion Performance of Plasma-Sprayed Co-based Composite Coatings with Additions of Al2O3 and CeO2(Springer New York LLC barbara.b.bertram@gsk.com, 2017) Nithin, H.S.; Desai, V.; Ramesh, M.R.In this paper, investigation into solid particle erosion behavior of atmospheric plasma-sprayed composite coating of CoCrAlY reinforced with Al2O3 and CeO2 oxides on Superni 76 at elevated temperature of 600 °C is presented. Alumina particles are used as erodent at two impact angles of 30° and 90°. The microstructure, porosity, hardness, toughness and adhesion properties of the as-sprayed coatings are studied. The effects of temperature and phase transformation in the coatings during erosion process are analyzed using XRD and EDS techniques. Optical profilometer is used for accurate elucidation of erosion volume loss. CoCrAlY/CeO2 coating showed better erosion resistance with a volume loss of about 50% of what was observed in case of CoCrAlY/Al2O3/YSZ coating. Lower erosion loss is observed at 90° as compared to 30° impact angle. The erosion mechanism evaluated using SEM micrograph revealed that the coatings experienced ductile fracture exhibiting severe deformation with unusual oxide cracks. Reinforced metal oxides provide shielding effect for erodent impact, enabling better erosion resistance. The oxidation of the coating due to high-temperature exposure reforms erosion process into oxidation-modified erosion process. © 2017, ASM International.Item Effect of Mo- and SiC-Reinforced NiCr Microwave Cladding on Microstructure, Mechanical and Wear Properties(Springer, 2023) Sharanabasava, H.; Prasad, C.D.; Ramesh, M.R.A microwave hybrid heating technique was applied to produce the NiCr-Mo-SiC composite cladding on Titan-31. The developed claddings were tested for microstructural features, phase analysis, microhardness, and surface roughness parameters using scanning electron microscopy (SEM), X-ray diffraction (XRD), Vickers Microhardness, and 3D optical profilometers, respectively. Using a static alumina indenter on microwave clads, the linear reciprocator ball on plate wear test was performed. Both friction and wear track metrics have been studied. A dense microstructure without observable holes or fractures has been achieved, together with a homogeneous distribution of hard phases and strong metallurgical bonding. Cladding is typically three times tougher than the underlying metal. Due to the formation of hard carbide phases, which increased hardness and internal lubricity, cladding has a lower coefficient of friction than the substrate. © 2023, The Institution of Engineers (India).