Faculty Publications
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Item Fabrication of stainless steel based composite by metal injection moulding(Elsevier Ltd, 2018) Veeresh Nayak, C.; Ramesh, M.R.; Desai, V.; Kumar Samanta, S.K.Metal injection moulding (MIM) is large scale manufacturing method, for creation of complex shapes and miniature parts by a combination of plastic injection moulding with the flexibility in sintering of metal particulates. In current investigation binder comprised of paraffin wax, polyethylene glycol, stearic acid and low-density polyethylene are developed for moulding of composite powders of SS316L+WC-CrC-Ni, and sintered at 1200°C under hydrogen purged atmosphere. Composites are characterised with respect to rheological, thermal properties and microstructure by scanning electron microscopy, microhardness and density. Properties of sintering temperature and heating rate on the above properties have been evaluated to obtain a defect-free composite. © 2017 Elsevier Ltd.Item Evolution of microstructure and hardness of AL-SI functionally graded material cast through centrifuge technique using hypereutectic and eutectic Al-SI(2011) Kiran Aithal, A.S.; Desai, V.; Narendranath; Mukunda, P.G.Functionally Graded Materials (FGMs) are a new class of inhomogeneous materials wherein the composition and the microstructure is varied to alter the material property within a component. The present study is to fabricate a Functionally Graded Al-Si in-situ material and to characterize. Al-Si alloys with 17wt%Si (hyper eutectic) and 11.7wt%Si (eutectic) have been used to fabricate Al- Si FGMsby centrifuge casting process. The microstructural characteristics and hardness profiles of these FGMs have been evaluated. The study shows the structure of Al-Si samples produced by this method show Hyper eutectic through Eutectic to Hypo eutectic structure along their depth. It also reveals that hardness of the sample and the silicon content decrease steeply along the depth of the sample.Item The influence of the addition of 4.5 wt.% of copper on wear properties of Al-12Si eutectic alloy(Hashemite University huniv@hu.edu.jo, 2015) Channappagoudar, S.; Kiran Aithal, K.; Sannayallappa, N.; Desai, V.; Mukunda, P.G.The influence of 4.5 wt.% copper addition on wear behavior of as-cast Al-12Si alloy prepared by gravity casting is investigated in dry sliding against a steel counterface using a pin-on-disk apparatus. The microstructures of test alloys and worn surfaces were examined by scanning electron microscopy and energy dispersing X-ray spectroscopy. The addition of copper to the binary Al-12Si alloy led to the precipitation of CuAl2 phase. Copper addition resulted in a refinement of ?-Al and a minor modification of eutectic Si. The Al-12Si-4.5Cu alloy showed a higher wear resistance as compared to Al-12Si binary eutectic alloy. © 2015 Jordan Journal of Mechanical and Industrial Engineering. All rights reserved.Item Effect of combined grain refinement and modification on microstructure and mechanical properties of hypoeutectic, eutectic and hypereutectic Al-Si alloys(Inderscience Publishers, 2015) Shivaprasad, C.G.; Kiran Aithal, K.; Narendranath, S.; Desai, V.; Mukunda, P.G.The effect of melt treatment owing to the combined addition of grain refiner and modifier on the microstructure and mechanical properties of Al-Si alloys having 7% (hypoeutectic), 12% (eutectic) and 15% silicon (hypereutectic) is studied. 1 wt. % of Al-1Ti-3B Master alloy was used as grain refiner. For modification of eutectic Si, 0.2 wt. % of Al-10Sr Master alloy was added to hypoeutectic alloy and 0.4 wt. % is added to eutectic alloy as well as hypereutectic alloy. Furthermore, refinement of primary Si in hypereutectic alloy was achieved by addition of 0.04 wt. % of phosphorus. The goal of this investigation is to determine the influence of combined addition of grain refiner and modifier on mechanical properties and qualitatively correlate with the microstructural changes. © 2015 Inderscience Enterprises Ltd.Item Influence of combined grain refinement and modification on the microstructure, tensile strength and wear properties of Al-15Si, Al-15Si-4.5Cu alloys(Carl Hanser Verlag Kolbergerstrasse 22 Munchen D-81679, 2015) Channappagoudar, S.; Sannayallappa, N.; Desai, V.; Venkateswarlu, V.Microstructure, tensile strength and dry sliding wear studies of Al-15Si, Al-15Si-4.5Cu alloys with and without grain refinement and modifications are presented. Experimental alloys such as Al-15Si and Al-15Si-4.5Cu were conventionally melted and gravity die cast. For grain refinement, 1 wt.% of Al-1Ti-3B and for modification, 0.17 wt.% of aluminum phosphide (AlP) and 0.4 wt.% of Al-10Sr were added to the alloy melt. The results reveal refined microstructure due to grain refinement, modification, improved hardness, higher tensile strength and better sliding wear. Moreover, Al-15Si-4.5Cu alloy (untreated and treated) showed improved mechanical properties as compared to conventional hypereutectic Al-Si alloy. © Carl Hanser Verlag GmbH & Co. KG.Item Influence of combined grain refinement and modification on the Microstructure, tensile strength and wear properties of Al-15Si, Al-15Si-4.5Cu alloys(Carl Hanser Verlag Kolbergerstrasse 22 Munchen D-81679, 2015) Channappagoudar, S.; Sannayallappa, N.; Desai, V.; Venkateswarlu, V.Microstructure, tensile strength and dry sliding wear studies of Al-15Si, Al-15Si-4.5Cu alloys with and without grain refinement and modifications are presented. Experimental alloys such as Al-15Si and Al-15Si-4.5Cu were conventionally melted and gravity die cast. For grain refinement, 1 wt.% of Al-1Ti-3B and for modification, 0.17 wt.% of aluminum phosphide (AlP) and 0.4 wt.% of Al-10Sr were added to the alloy melt. The results reveal refined microstructure due to grain refinement, modification, improved hardness, higher tensile strength and better sliding wear. Moreover, Al-15Si-4.5Cu alloy (untreated and treated) showed improved mechanical properties as compared to conventional hypereutectic Al-Si alloy. © Carl Hanser Verlag GmbH & Co. KG ISSN 1862-5282.Item Evaluation of Wear Behaviour of Metal Injection Moulded Nickel Based Metal Matrix Composite(Springer Netherlands rbk@louisiana.edu, 2019) Veeresh Nayak, V.N.; Ramesh, M.R.; Desai, V.; Kumar Samanta, S.K.Metal injection moulding (MIM) is a near-net shape manufacturing technology for producing intricate parts, cost-effectively. MIM comprises combined techniques of plastic injection moulding and powder metallurgy. The present study focused on the development of the binder and fabrication of defect free MIM component. A wax-based binder system consisting of paraffin wax (PW), low density polyethylene (LDPE), polyethylene glycol (PEG-600) and stearic acid was established for MIM of NiCrSiB (70% Wt.) + Cr3C2-NiCr (30% Wt.) nickel based metal matrix composite (NMMC) powder. The feedstock was characterised through rheological properties at different temperatures. Injection temperature was determined from the rheological investigation of the feedstock having the 56% powder loading and 44% binder by volume. Sintering process was carried out with the temperature cycle in the range of 1250–1300 ?C under hydrogen purged atmosphere. The MIM components showed good and acceptable shrinkage in linear dimensions. The mechanical properties and wear behaviour of NMMC was studied using a pin-on-disc apparatus with alumina disc.Tests were performed under dry sliding conditions at room temperature and elevated temperatures of 200 and 400 ?C. Results shows that wear rate is maximum at 400 ?C for 40 N and lowest at room temperature for 10 N. Further wear mechanism was analysed using scanning electron microscope (SEM). © 2018, Springer Science+Business Media B.V., part of Springer Nature.Item Sintering metal injection molding parts of tungsten-based steel using microwave and conventional heating methods(SAGE Publications Ltd info@sagepub.co.uk, 2019) Veeresh Nayak, C.; Ramesh, M.R.; Desai, V.; Kumar Samanta, S.K.In recent years, the near net shape metal injection molding process combines desirable features of plastic injection molding and powder metallurgy processes to gain high strength-to-weight ratio for manufacturing complex-shaped parts. The metal injection molding process consists of mixing, molding, debinding, and sintering. Microwave processing has attracted much attention in global research because of its unique features such as its ability to heat and sinter a wide variety of metals and its significant advantages in energy efficiency, processing speed, and compatibility. Also, it presents few environmental risks and can produce refined microstructures. The injected samples to be sintered are composed of fine tool steel metal powder and binders, stearic acid, paraffin wax, low-density polyethylene, and polyethylene glycol (600). In recent years, microwave-assisted post-treatment is considered a novel method for processing green parts. In this work, the green parts are subjected to high-intensity microwave fields which operate at a frequency of 2.45 GHz. Metal injection molding compacts were sintered using multi-mode microwave radiation. The sintering of a metal injection molding compact by microwaves has hardly been reported. The metal injection molding compact showed better results than those produced by sintering with conventional heating. This study evaluates the effect of conventional sintering and microwave sintering on mechanical properties. By optimizing the sintering process, increased sintered hardness, a more homogeneous microstructure, and greater shrinkage were obtained using microwave-assisted sintering. © IMechE 2018.