Browsing by Author "Manakari, V."

Now showing 1 - 11 of 11

Dry sliding wear of epoxy/cenosphere syntactic foams
(Elsevier Ltd, 2015) Manakari, V.; Parande, G.; Doddamani, M.; Gaitonde, V.N.; Siddhalingeshwar, I.G.; Kishore; Shunmugasamy, V.C.; Gupta, N.
Abstract Dry sliding wear behavior of epoxy matrix syntactic foams filled with 20, 40 and 60 wt% fly ash cenosphere is reported based on response surface methodology. Empirical models are constructed and validated based on analysis of variance. Results show that syntactic foams have higher wear resistance than the matrix resin. Among the parameters studied, the applied normal load (F) had a prominent effect on wear rate, specific wear rate (ws) and coefficient of friction (?). With increasing F, the wear rate increased, whereas ws and ? decreased. With increase in filler content, the wear rate and ws decreased, while the ? increased. With increase in sliding velocity as well as sliding distance, the wear rate and ws show decreasing trends. Microscopy revealed broken cenospheres forming debris and extensive deformation marks on the wear surface. © 2015 Elsevier Ltd.
Enhancing the ignition, hardness and compressive response of magnesium by reinforcing with hollow glass microballoons
(MDPI AG Postfach Basel CH-4005, 2017) Manakari, V.; Parande, G.; Doddamani, M.; Gupta, M.
Magnesium (Mg)/glass microballoons (GMB) metal matrix syntactic foams (1.47-1.67 g/cc) were synthesized using a disintegrated melt deposition (DMD) processing route. Such syntactic foams are of great interest to the scientific community as potential candidate materials for the ever-changing demands in automotive, aerospace, and marine sectors. The synthesized composites were evaluated for their microstructural, thermal, and compressive properties. Results showed that microhardness and the dimensional stability of pure Mg increased with increasing GMB content. The ignition response of these foams was enhanced by -22 °C with a 25 wt % GMB addition to the Mg matrix. The authors of this work propose a new parameter, ignition factor, to quantify the superior ignition performance that the developed Mg foams exhibit. The room temperature compressive strengths of pure Mg increased with the addition of GMB particles, with Mg-25 wt % GMB exhibiting the maximum compressive yield strength (CYS) of 161 MPa and an ultimate compressive strength (UCS) of 232 MPa for a GMB addition of 5 wt % in Mg. A maximum failure strain of 37.7% was realized in Mg-25 wt % GMB foam. The addition of GMB particles significantly enhanced the energy absorption by -200% prior to compressive failure for highest filler loading, as compared to pure Mg. Finally, microstructural changes in Mg owing to the presence of hollow GMB particles were elaborately discussed. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.
Evaluation of wear resistance of magnesium/glass microballoon syntactic foams for engineering/biomedical applications
(Elsevier Ltd, 2019) Manakari, V.; Parande, G.; Doddamani, M.; Gupta, M.
Friction and wear behaviour of magnesium/glass microballoon (GMB) foams synthesized by Disintegrated Melt Deposition (DMD) were investigated under dry sliding conditions. The coefficient of friction (?) decreases with increasing GMB content. Mg-25wt.% GMB exhibits ?13% lower ? pure compared to magnesium. Wear resistance of magnesium showed a significant enhancement (?2.5 times) post GMB addition. Abrasion and oxidation were identified as dominant wear mechanisms post worn-surface analysis. Delamination wear, which has traditionally limited the advantages of composites with discontinuous reinforcements in sliding wear conditions for structural and biomedical applications can be effectively addressed by the development of these proposed syntactic foams. © 2019 Elsevier Ltd and Techna Group S.r.l.
In-vitro degradation of hollow silica reinforced magnesium syntactic foams in different simulated body fluids for biomedical applications
(MDPI AG, 2020) Manakari, V.; Kannan, S.; Parande, G.; Doddamani, M.; Columbus, S.; Priya Sudha, K.; Vincent, S.; Gupta, M.
This article reports the mechanical and biocorrosion behaviour of hollow silica nanosphere (SiO2) reinforced (0.5–2 vol.%) magnesium (Mg) syntactic foams. Room temperature tensile properties’ characterization suggests that the increased addition of hollow silica nanospheres resulted in a progressive increase in tensile yield strength (TYS) and ultimate tensile strength (UTS) with Mg-2 vol.% SiO2 exhibiting a maximum TYS of 167 MPa and a UTS of 217 MPa. The degradation behaviour of the developed Mg-SiO2 syntactic foams in four different simulated body fluids (SBFs): artificial blood plasma solution (ABPS), phosphate-buffered saline solution (PBS), artificial saliva solution (ASS) and Hanks’ balanced saline solution (HBSS) was investigated by using potentiodynamic polarization studies. Results indicate that corrosion resistance of the Mg-SiO2 syntactic foam decreases with increasing chloride ion concentration of the SBF. Mg-1.0 vol.% SiO2 displayed the best corrosion response and its corrosion susceptibility pertaining to corrosion rate and polarisation curves in different SBF solutions can be ranked in the following order: ABPS > PBS > HBSS > ASS. The surface microstructure demonstrated the presence of a better passivated layer on the syntactic foams compared to pure Mg. The observed increase in corrosion resistance is correlated with intrinsic changes in microstructure due to the presence of hollow silica nanospheres. Further, the effect of corrosive environment on the degradation behaviour of Mg has been elucidated. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
Metal Matrix Syntactic Composites
(Elsevier, 2021) Manakari, V.; Parande, G.; Gupta, M.; Doddamani, M.
Syntactic foams have attracted considerable attention in recent years due to their potential for weight saving in packaging, armours, and vehicle structures. Metal matrix syntactic foams (MMSFs) are lightweight closed-cell composite foams produced by reinforcing hollow particles in the metal matrix. MMSFs can be synthesized with mechanical properties high enough to enable them to be used for load-bearing applications, raising the possibilities of structural weight reduction in numerous applications. Significant research efforts have been carried out on Mg, Al, Pb, Zn, Ti, Ni, Fe, and Invar matrix syntactic foams in recent years to tailor and enhance mechanical properties based on end applications. The present chapter reviews the recent state of the art in metal matrix syntactic foams and presents the fundamentals of structure-property correlations for syntactic foamsand synthesis methods that aid in developing multifunctionality in these composites. This chapter also reviews the weight saving ability of metal matrix syntactic foams and their potential scope and applications. © 2021 Elsevier Ltd. All rights reserved.
Role of Rare Earth Oxide Reinforcements in Enhancing the Mechanical, Damping and Ignition Resistance of Magnesium
(2019) Kujur, M.S.; Manakari, V.; Parande, G.; Doddamani, M.; Mallick, A.; Gupta, M.
Magnesium based nanocomposites, on account of their excellent dimensional stability coupled with mechanical integrity, have provided the much-needed impetus for utilization in both aerospace-related and automobile-related applications. However, the perceived easy ignition and flammability of magnesium alloys create a detrimental safety feature that hinders the aerospace application opportunities. Incorporation of rare earth metal oxides into magnesium matrix can induce �reactive element effect� (REE), due to their strong rare earth�oxygen interactions. Along with enhancing the protective characteristics of oxides on many metals and alloys, the addition of such rare earth oxides also helps in realizing a refined microstructure and good strength�ductility combination in the composites. This manuscript presents the mechanical properties, damping and ignition resistance characteristics of the new and improved composite materials engineered by reinforcing magnesium with rare earth oxide nanoparticle. Rationale for the observed properties is discussed while concurrently establishing the relationship between microstructure of the engineered composites and resultant mechanical properties. � 2019, The Minerals, Metals & Materials Society.
Role of Rare Earth Oxide Reinforcements in Enhancing the Mechanical, Damping and Ignition Resistance of Magnesium
(Springer, 2019) Kujur, M.S.; Manakari, V.; Parande, G.; Doddamani, M.; Mallick, A.; Gupta, M.
Magnesium based nanocomposites, on account of their excellent dimensional stability coupled with mechanical integrity, have provided the much-needed impetus for utilization in both aerospace-related and automobile-related applications. However, the perceived easy ignition and flammability of magnesium alloys create a detrimental safety feature that hinders the aerospace application opportunities. Incorporation of rare earth metal oxides into magnesium matrix can induce â€˜reactive element effectâ€™ (REE), due to their strong rare earthâ€“oxygen interactions. Along with enhancing the protective characteristics of oxides on many metals and alloys, the addition of such rare earth oxides also helps in realizing a refined microstructure and good strengthâ€“ductility combination in the composites. This manuscript presents the mechanical properties, damping and ignition resistance characteristics of the new and improved composite materials engineered by reinforcing magnesium with rare earth oxide nanoparticle. Rationale for the observed properties is discussed while concurrently establishing the relationship between microstructure of the engineered composites and resultant mechanical properties. Â© 2019, The Minerals, Metals & Materials Society.
Tribological response of cenosphere/epoxy syntactic foams
(2015) Manakari, V.; Parande, G.; Bafna, K.; Doddamani, M.; Gupta, N.
Fly ash cenospheres are generated in thermal power plants as waste materials. Use of these waste materials in beneficial applications is desired. The present work deals with developing syntactic foams with fly ash cenospheres filled in epoxy resin matrix. Such syntactic foams can be used as core materials in sandwich composites. The fabricated syntactic foams are evaluated for dry sliding wear behavior. Sliding velocity and filler content were the study parameters, effects of which were analyzed on wear rate. Specimens were prepared with 10, 30 and 50 wt. % cenospheres for the study. Sliding against hardened ground steel on a pin-on disc wear testing machine was conducted. The experimental results and subsequent analysis showed that the addition of cenospheres as filler material in epoxy matrix considerably increases the wear resistance of the composites. The craters on the specimen surface due to presence of cenospheres play important role in the wear process. Copyright � 2015 by DEStech Publications, Inc. and American Society for Composites. All rights reserved.
Tribological response of cenosphere/epoxy syntactic foams
(DEStech Publications, 2015) Manakari, V.; Parande, G.; Bafna, K.; Doddamani, M.; Gupta, N.
Fly ash cenospheres are generated in thermal power plants as waste materials. Use of these waste materials in beneficial applications is desired. The present work deals with developing syntactic foams with fly ash cenospheres filled in epoxy resin matrix. Such syntactic foams can be used as core materials in sandwich composites. The fabricated syntactic foams are evaluated for dry sliding wear behavior. Sliding velocity and filler content were the study parameters, effects of which were analyzed on wear rate. Specimens were prepared with 10, 30 and 50 wt. % cenospheres for the study. Sliding against hardened ground steel on a pin-on disc wear testing machine was conducted. The experimental results and subsequent analysis showed that the addition of cenospheres as filler material in epoxy matrix considerably increases the wear resistance of the composites. The craters on the specimen surface due to presence of cenospheres play important role in the wear process. Â© Â© 2015 by DEStech Publications, Inc. and American Society for Composites. All rights reserved.
Tribological Response of Magnesium/Glass Microballoon Syntactic Foams
(Springer Science and Business Media Deutschland GmbH, 2022) Manakari, V.; Parande, G.; Doddamani, M.; Srivatsan, T.S.; Gupta, M.
Magnesium (Mg)-based materials have great potential to replace the existing aluminum alloys and steels used in applications spanning the industries of defense, aerospace, and automotive due in essence to their excellent specific strength [σ/ρ], damping characteristics, and impact resistance. In this research study, we design an ultralow density magnesium/glass microballoon (GMB) syntactic foam having a density of 1.47 g/cc using the technique of Disintegrated Melt Deposition (DMD). The resultant material offered a healthy combination of extraordinary properties outperforming the existing aluminium and iron syntactic foams in terms of a noticeable improvement in specific strength [σ/ρ]. Further, the wear resistance of magnesium under dry sliding conditions showed a significant enhancement (~2.5 times) following the addition of glass microballoon (GMB). Abrasion and oxidation were identified to be the dominant wear mechanisms post worn-surface analysis. Morphology of the worn specimen provided clean, clear, and convincing evidence for the occurrence of delamination wear, which has traditionally limited the competitive advantage of magnesium and its alloy counterparts for selection and use in safety–critical components in transportation vehicles. This can be effectively overcome by the development of the proposed syntactic foams, which provide a unique cushioning effect against the applied load. © 2022, The Minerals, Metals & Materials Society.
Wear response of walnut-shell-reinforced epoxy composites
(ASTM International, 2017) Doddamani, M.; Parande, G.; Manakari, V.; Siddhalingeshwar, I.G.; Gaitonde, V.N.; Gupta, N.
Present work utilizes agricultural by-product, walnut shell, as reinforcing filler in epoxy matrix for investigating dry sliding wear behavior using a pin-on disc wear-testing machine. Effects of sliding velocity (0.5-1.5 m/s), normal load (10-50 N), sliding distance (1000-3000 m) and filler content (10-30 wt. %) on wear rate (Wt), specific wear rate (Ws) and coefficient of friction (?) are investigated. The experiments were planned as per design of the experiments scheme and the wear characteristics were analyzed through response surface modeling (RSM) method. The lowest Wt of 1.1 mm3/km was noted for 1.5 m/s sliding velocity with 30-wt. % filler content. Sliding distance did not have a significant influence on Ws above a critical load of 40 N. The minimum ? was observed at 1-m/s sliding velocity, 40-N load, 1000-m sliding distance, and 30-wt. % filler. Lower values of Wt and ? at higher walnut-shell loadings support feasibility of using such composites in wear-prone applications. The wear mechanism was determined in the composites using extensive scanning electron microscopic observations. © © 2017 by ASTM International.