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Nikhil Gupta - One of the best experts on this subject based on the ideXlab platform.
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additive manufacturing of syntactic foams part 2 specimen printing and mechanical property characterization
2018Co-Authors: Ashish Kumar Singh, Mrityunjay Doddamani, Brooks Saltonstall, Balu Patil, Niklas Hoffmann, Nikhil GuptaAbstract:High-density polyethylene (HDPE) and its fly ash cenosphere-filled syntactic foam filaments have been recently developed. These filaments are used for three-dimensional (3D) printing using a commercial printer. The developed syntactic foam filament (HDPE40) contains 40 wt.% Cenospheres in the HDPE matrix. Printing parameters for HDPE and HDPE40 were optimized for use in widely available commercial printers, and specimens were three-dimensionally (3D) printed for tensile testing at strain rate of 10−3 s−1. Process optimization resulted in smooth operation of the 3D printer without nozzle clogging or cenosphere fracture during the printing process. Characterization results revealed that the tensile modulus values of 3D-printed HDPE and HDPE40 specimens were higher than those of injection-molded specimens, while the tensile strength was comparable, but the fracture strain and density were lower.
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quasi static and high strain rate compressive response of injection molded cenosphere hdpe syntactic foam
2016Co-Authors: B Bharath R Kumar, Mrityunjay Doddamani, Ashish Kumar Singh, Dung D Luong, Nikhil GuptaAbstract:High strain rate compressive properties of high-density polyethylene (HDPE) matrix syntactic foams containing cenosphere filler are investigated. Thermoplastic matrix syntactic foams have not been studied extensively for high strain rate deformation response despite interest in them for lightweight underwater vehicle structures and consumer products. Quasi-static compression tests are conducted at 10−4 s−1, 10−3 s−1 and 10−2 s−1 strain rates. Further, a split-Hopkinson pressure bar is utilized for characterizing syntactic foams for high strain rate compression. The compressive strength of syntactic foams is higher than that of HDPE resin at the same strain rate. Yield strength shows an increasing trend with strain rate. The average yield strength values at high strain rates are almost twice the values obtained at 10−4 s−1 for HDPE resin and syntactic foams. Theoretical models are used to estimate the effectiveness of Cenospheres in reinforcing syntactic foams.
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data characterizing tensile behavior of cenosphere hdpe syntactic foam
2016Co-Authors: B Bharath R Kumar, Mrityunjay Doddamani, Nikhil Gupta, Steven E Zeltmann, Seeram RamakrishnaAbstract:The data set presented is related to the tensile behavior of cenosphere reinforced high density polyethylene syntactic foam composites “Processing of cenosphere/HDPE syntactic foams using an industrial scale polymer injection molding machine” (Bharath et al., 2016) [1]. The focus of the work is on determining the feasibility of using an industrial scale polymer injection molding (PIM) machine for fabricating syntactic foams. The fabricated syntactic foams are investigated for microstructure and tensile properties. The data presented in this article is related to optimization of the PIM process for syntactic foam manufacture, equations and procedures to develop theoretical estimates for properties of Cenospheres, and microstructure of syntactic foams before and after failure. Included dataset contains values obtained from the theoretical model.
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processing of cenosphere hdpe syntactic foams using an industrial scale polymer injection molding machine
2016Co-Authors: Harath R Kuma, Steven Eric Zeltma, M R Ramesh, Mrityunjay Doddamani, Nikhil Gupta, Seeram RamakrishnaAbstract:Abstract Rapid production of high quality components is the key to cost reduction in industrial applications. The present work is the first attempt of manufacturing syntactic foams, hollow particle filled lightweight composites, using an industrial scale injection molding machine. High density polyethylene (HDPE) is used as the matrix material and fly ash Cenospheres are used as the filler. Development of syntactic foams with Cenospheres serves dual purpose of beneficial utilization of industrial waste fly ash and reduction in the cost of the component. The pressure and temperature used in the injection molding process are optimized to minimize fracture of Cenospheres and obtain complete mixing of Cenospheres with HDPE. The optimized parameters are used for manufacturing syntactic foams with 20, 40 and 60 wt.% Cenospheres. With increasing cenosphere content, density and strength reduce and modulus increases. Surface modification of constituents results in rise in strength with increasing filler content. A theoretical model based on a differential scheme is used to estimate the properties of Cenospheres by conducting parametric studies because of inherent difficulties in direct measurement of cenosphere properties. The potential for using the optimized injection molding process is demonstrated by casting several industrial components.
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effect of particle surface treatment and blending method on flexural properties of injection molded cenosphere hdpe syntactic foams
2016Co-Authors: B Bharath R Kumar, Mrityunjay Doddamani, Nikhil Gupta, Steven E Zeltmann, S Gurupadu, R R N SailajaAbstract:The present work on cenosphere/high-density polyethylene (HDPE) syntactic foams aims at understanding the effect of surface treatment of Cenospheres and functionalization of HDPE on flexural properties. Cenospheres are treated with silane, and HDPE is functionalized with 10 % dibutyl maleate. Effects of mechanical and Brabender mixing methods are also studied. Flexural test specimens are cast with 20, 40, and 60 wt% of Cenospheres using injection molding. The flexural modulus and strength are found to increase with increasing cenosphere content. Particle breakage increases with the cenosphere content, and the measured properties show increased dependence on processing method. Brabender mixing resulted in 70 and 41 % higher modulus and strength for 60 wt% Cenospheres than HDPE. Modulus of syntactic foams is predicted by two theoretical models. Bardella–Genna model provides close estimates for syntactic foams having 20 and 40 wt% Cenospheres, while predictions are higher for higher cenosphere content, likely due to particle breakage during processing. The uncertainty in the properties of Cenospheres due to defects contributes to the variation in the predicted values.
Mrityunjay Doddamani - One of the best experts on this subject based on the ideXlab platform.
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microstructure and tribological behavior of plasma sprayed nicraly wc co cenosphere solid lubricants composite coatings
2018Co-Authors: Mrityunjay Doddamani, Mahantayya Mathapati, M R RameshAbstract:Abstract Present investigation deal with NiCrAlY/WC-Co/Cenosphere/MoS2/CaF2, NiCrAlY/WC-Co/Cenosphere/MoS2/CaSO4 and NiCrAlY/WC-Co/Cenosphere coatings deposited on MDN 321 steel using atmospheric plasma spraying. Tribological properties of MDN 321 steel and coatings are evaluated from room temperature (RT) to 600 °C under dry lubrication conditions using a pin on disc high-temperature tribometer. Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Energy Dispersive Spectroscopy (EDS) are used to characterize the coatings. Presence of Cenospheres in these coatings might effectively reduce wear acting as localized regions accumulating wear debris. The result shows that wear rate of all the coatings are lower as compared to MDN 321 substrate at all the test conditions. NiCrAlY/WC-Co/Cenosphere/MoS2/CaF2 and NiCrAlY/WC-Co/Cenosphere/MoS/CaSO4 coatings registered lower friction coefficient as compared to NiCrAlY/WC-Co/Cenosphere coating and MDN 321 substrate. Characterization of the NiCrAlY/WC-Co/Cenosphere/MoS2/CaF2 and NiCrAlY/WC-Co/Cenosphere/MoS2/CaSO4 coatings worn out surface suggests that MoS2 provides lubrication at 200 °C and formation of CaMoO4, MoO3 through tribo chemistry reaction at higher temperature provides lubrication at 600 °C. SEM micrograph of worn surface demonstrates that the main wear mechanism is plowing and delamination.
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additive manufacturing of syntactic foams part 2 specimen printing and mechanical property characterization
2018Co-Authors: Ashish Kumar Singh, Mrityunjay Doddamani, Brooks Saltonstall, Balu Patil, Niklas Hoffmann, Nikhil GuptaAbstract:High-density polyethylene (HDPE) and its fly ash cenosphere-filled syntactic foam filaments have been recently developed. These filaments are used for three-dimensional (3D) printing using a commercial printer. The developed syntactic foam filament (HDPE40) contains 40 wt.% Cenospheres in the HDPE matrix. Printing parameters for HDPE and HDPE40 were optimized for use in widely available commercial printers, and specimens were three-dimensionally (3D) printed for tensile testing at strain rate of 10−3 s−1. Process optimization resulted in smooth operation of the 3D printer without nozzle clogging or cenosphere fracture during the printing process. Characterization results revealed that the tensile modulus values of 3D-printed HDPE and HDPE40 specimens were higher than those of injection-molded specimens, while the tensile strength was comparable, but the fracture strain and density were lower.
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quasi static and high strain rate compressive response of injection molded cenosphere hdpe syntactic foam
2016Co-Authors: B Bharath R Kumar, Mrityunjay Doddamani, Ashish Kumar Singh, Dung D Luong, Nikhil GuptaAbstract:High strain rate compressive properties of high-density polyethylene (HDPE) matrix syntactic foams containing cenosphere filler are investigated. Thermoplastic matrix syntactic foams have not been studied extensively for high strain rate deformation response despite interest in them for lightweight underwater vehicle structures and consumer products. Quasi-static compression tests are conducted at 10−4 s−1, 10−3 s−1 and 10−2 s−1 strain rates. Further, a split-Hopkinson pressure bar is utilized for characterizing syntactic foams for high strain rate compression. The compressive strength of syntactic foams is higher than that of HDPE resin at the same strain rate. Yield strength shows an increasing trend with strain rate. The average yield strength values at high strain rates are almost twice the values obtained at 10−4 s−1 for HDPE resin and syntactic foams. Theoretical models are used to estimate the effectiveness of Cenospheres in reinforcing syntactic foams.
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data characterizing tensile behavior of cenosphere hdpe syntactic foam
2016Co-Authors: B Bharath R Kumar, Mrityunjay Doddamani, Nikhil Gupta, Steven E Zeltmann, Seeram RamakrishnaAbstract:The data set presented is related to the tensile behavior of cenosphere reinforced high density polyethylene syntactic foam composites “Processing of cenosphere/HDPE syntactic foams using an industrial scale polymer injection molding machine” (Bharath et al., 2016) [1]. The focus of the work is on determining the feasibility of using an industrial scale polymer injection molding (PIM) machine for fabricating syntactic foams. The fabricated syntactic foams are investigated for microstructure and tensile properties. The data presented in this article is related to optimization of the PIM process for syntactic foam manufacture, equations and procedures to develop theoretical estimates for properties of Cenospheres, and microstructure of syntactic foams before and after failure. Included dataset contains values obtained from the theoretical model.
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processing of cenosphere hdpe syntactic foams using an industrial scale polymer injection molding machine
2016Co-Authors: Harath R Kuma, Steven Eric Zeltma, M R Ramesh, Mrityunjay Doddamani, Nikhil Gupta, Seeram RamakrishnaAbstract:Abstract Rapid production of high quality components is the key to cost reduction in industrial applications. The present work is the first attempt of manufacturing syntactic foams, hollow particle filled lightweight composites, using an industrial scale injection molding machine. High density polyethylene (HDPE) is used as the matrix material and fly ash Cenospheres are used as the filler. Development of syntactic foams with Cenospheres serves dual purpose of beneficial utilization of industrial waste fly ash and reduction in the cost of the component. The pressure and temperature used in the injection molding process are optimized to minimize fracture of Cenospheres and obtain complete mixing of Cenospheres with HDPE. The optimized parameters are used for manufacturing syntactic foams with 20, 40 and 60 wt.% Cenospheres. With increasing cenosphere content, density and strength reduce and modulus increases. Surface modification of constituents results in rise in strength with increasing filler content. A theoretical model based on a differential scheme is used to estimate the properties of Cenospheres by conducting parametric studies because of inherent difficulties in direct measurement of cenosphere properties. The potential for using the optimized injection molding process is demonstrated by casting several industrial components.
Weihong Huang - One of the best experts on this subject based on the ideXlab platform.
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h2o2 modified surface of tio2 fly ash Cenospheres and enhanced photocatalytic activity on methylene blue
2010Co-Authors: Pengwei Huo, Weihong Huang, Yongsheng Yan, Songtao Chen, Xiaojie ZhangAbstract:Abstract In this study, the TiO2/fly-ash Cenospheres were prepared via sol–gel method, and the surface of TiO2/fly-ash Cenospheres was further modified by hydrogen peroxide (H2O2). Scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–vis diffuse reflectance spectra (UV–vis DRS), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS) were applied to characterize structure, performance and chemical composition of as-prepared samples. The photocatalytic activity of as-prepared samples was evaluated by degradation of methylene blue under visible light irradiation. The results indicate that the modified phototcatalyst of TiO2/fly-ash Cenospheres is effectively improved the absorption of light. The photocatalytic degradation of methylene blue is enhanced under visible light irradiation, which the degradation rate is higher 42.5% than the untreated TiO2/fly-ash Cenospheres with H2O2. Moreover, the simple way to modified TiO2/fly-ash Cenospheres and enhancing the photocatalytic activity is better for practical application.
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floating photocatalysts of fly ash Cenospheres supported agcl tio2 films with enhanced rhodamine b photodecomposition activity
2010Co-Authors: Songtian Li, Huaming Li, Weihong HuangAbstract:Abstract Floating fly-ash Cenospheres supported AgCl/TiO 2 films photocatalysts were prepared by a simple sol–gel method. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), thermo gravimetric analysis-differential scanning calorimeter (TG-DSC), and UV–vis diffuse reflection spectrum (UV–vis DRS). The results show that the fly-ash Cenospheres are coated with about 2 μm thickness of AgCl/TiO 2 nano-composite films. The fly-ash Cenospheres loaded the films of AgCl/TiO 2 photocatalysts exhibit high visible-light-induced photocatalytic activity for the decomposition of Rhodamine B waste water. When the photocatalyst contained the dosage of 0.21 g AgCl, the photo-degradation rate could reach 94.96% in 180 min under visible light irradiation, and removal rate of TOC could reach 20.34% in the same condition.
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preparation of poly o phenylenediamine tio2 fly ash Cenospheres and its photo degradation property on antibiotics
2010Co-Authors: Songtian Li, Huarning Li, Weihong HuangAbstract:Abstract A series of poly-o-phenylenediamine/TiO2/fly-ash Cenospheres(POPD/TiO2/fly-ash Cenospheres) composites have been prepared from o-phenylenediamine and TiO2/fly-ash Cenospheres under various polymerization conditions. The properties of the samples were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), specific surface area (BET), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and UV–vis diffuse reflectance spectrum (UV–vis DRS). Photocatalytic activity was studied by degradation of antibiotics waste water under visible light. The results indicate that the photo-induced method is viable for preparing modified photocatalysts, and the modified photocatalysts have good absorption in visible light range. The photocatalysts of POPD/TiO2/fly-ash Cenospheres which have good performance are prepared at pH 3 and 4, and the polymerized time around 40 min. When the photocatalysts are prepared under the conditions of pH 3 and polymerized time 40 min, the degradation rate of roxithromycin waste water could reach near 60%, and it indicates that the way of POPD modified TiO2/fly-ash Cenospheres to degrade the antibiotics waste water is viable.
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preparation and characterization of cobalt sulfophthalocyanine tio2 fly ash Cenospheres photocatalyst and study on degradation activity under visible light
2009Co-Authors: Pengwei Huo, Yongsheng Yan, Weihong HuangAbstract:Abstract Cobalt Sulfophthalocyanine (CoSPc) sensitized TiO2 sol samples were prepared through a Sol–Gel method using Cobalt Sulfophthalocyanine as a sensitizer. Loading and modified floating photocatalyst was prepared by hydrothermal method using fly-ash Cenospheres as a carrier. The properties of the samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and UV–vis diffuse reflectance spectrum (DRS). Photocatalytic activity was studied by degrading wastewater of methylene blue under visible light. The results indicate that the fly-ash Cenospheres are covered by modified TiO2 film which composed of the anatase, brookite and rutile misch crystal phase. CoSPc/TiO2/fly-ash Cenospheres samples have good catalytic activity under visible light, and have strong absorbency during 600–700 nm. The sensitization of CoSPc can enhance visible light catalytic activity of TiO2/fly-ash Cenospheres. The degradation rate of methylene blue reaches 73.36% in 180 min under the visible light illumination. But too much CoSPc can decrease its catalytic activity.
R R N Sailaja - One of the best experts on this subject based on the ideXlab platform.
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effect of particle surface treatment and blending method on flexural properties of injection molded cenosphere hdpe syntactic foams
2016Co-Authors: B Bharath R Kumar, Mrityunjay Doddamani, Nikhil Gupta, Steven E Zeltmann, S Gurupadu, R R N SailajaAbstract:The present work on cenosphere/high-density polyethylene (HDPE) syntactic foams aims at understanding the effect of surface treatment of Cenospheres and functionalization of HDPE on flexural properties. Cenospheres are treated with silane, and HDPE is functionalized with 10 % dibutyl maleate. Effects of mechanical and Brabender mixing methods are also studied. Flexural test specimens are cast with 20, 40, and 60 wt% of Cenospheres using injection molding. The flexural modulus and strength are found to increase with increasing cenosphere content. Particle breakage increases with the cenosphere content, and the measured properties show increased dependence on processing method. Brabender mixing resulted in 70 and 41 % higher modulus and strength for 60 wt% Cenospheres than HDPE. Modulus of syntactic foams is predicted by two theoretical models. Bardella–Genna model provides close estimates for syntactic foams having 20 and 40 wt% Cenospheres, while predictions are higher for higher cenosphere content, likely due to particle breakage during processing. The uncertainty in the properties of Cenospheres due to defects contributes to the variation in the predicted values.
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mechanical and thermal characteristics of high density polyethylene fly ash Cenospheres composites
2010Co-Authors: M V Deepthi, R R N Sailaja, Madan Sharma, P Anantha, P Sampathkumaran, S SeetharamuAbstract:Fly ash Cenospheres was used as reinforcing filler in High density polyethylene (HDPE) to develop lightweight composites. Cenospheres are inert hollow silicate spheres. Cenospheres are a naturally occurring by-product of the burning process at coal-fired power plants, and they have most of the same properties as manufactured hollow-sphere products. Cenospheres are primarily used to reduce the weight of plastics, rubbers, resins, cements, etc. used extensively as filler lubricants in oil drilling operations under high heat and high stress conditions down the hole. Also used as oil well cementing, mud putty and similar applications. Cenospheres were first used in the United States as an extender for plastic compounds, as they are compatible with plastisols thermoplastics, Latex, Polyesters, Epoxies, Phenolic resins and urethanes. The compatibility of Cenospheres with special cements and adhesives coating and composites have been well identified. Cenospheres are widely used in a variety of products, including sports equipments, insulation, automobile bodies, marine craft bodies, paints, and fire and heat protection devices. Typically applied in gypsum board jointing compounds, veneering plasters, stuccos, sealants, coating and cast resins. Providing the advantages of reduces weight, increased filler loadings, better flow characteristics, less shrinkage and warping and reduces water absorption. In order to improve the interaction between the inorganic filler and the organic matrix, the Cenospheres were surface treated with silane coupling agent and HDPE-g-dibutyl maleate was used as compatibilizer. The tensile and thermal properties of the composites were measured according to ASTM methods. The results reveal that, both surface modification of Cenospheres accompanied by compatibilization led to the substantial improvement to mechanical properties and thermal stability of the composites.
D P Mondal - One of the best experts on this subject based on the ideXlab platform.
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Compressive Deformation Behavior of Highly Porous AA2014-Cenosphere Closed Cell Hybrid Foam Prepared Using CaH_2 as Foaming Agent: Comparison with Aluminum Foam and Syntactic Foam
2017Co-Authors: Shyam Birla, D P Mondal, S Das, N. Prasanth, A. K. Jha, A. N. Ch. VenkatAbstract:Closed Cell AA2014-cenosphere hybrid foams have been prepared through stir-casting technique using varying amount of CaH_2 powder as foaming agent. The Cenospheres in hybrid foams created micro-pores in the cell wall and in the plateau region. It reduced the requirement of CaH_2 for foaming by 30–40% by attaining equivalent level of relative density. These foams have been characterized for of microarchitechtural characteristics and mechanical properties like strength, densification strain and energy absorption. The properties of hybrid foams have been compared with those of conventional AA2014-SiC foam and Al-cenosphere syntactic foam. The closed cell AA2014-cenosphere hybrid foam exhibited comparable plateau stress, densification strain and energy absorption characteristics to those of AA2014-SiC foams with same relative density. Empirical relations to correlate plateau stress, densification strain and energy absorption for entire range of porosities have been established.
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effect of cenosphere particle size and relative density on the compressive deformation behavior of aluminum cenosphere hybrid foam
2017Co-Authors: D P Mondal, Shyam Birla, S Das, Anup Khare, Jai Prakash SinghAbstract:Abstract AlSi12Cu1Mg1-cenosphere hybrid foams (HFs) of varying relative densities were made through stir casting technique using CaH 2 as a foaming agent. Cenospheres of different size ranges were used as a thickening agent, as well as to create micropores in the cell wall. The foaming temperature was varied to vary the relative density, which has not been studied earlier. The combine effect of cenosphere size and relative density on the compressive deformation behavior of HFs was investigated. The plastic collapse stress, plateau stress, and energy absorption of hybrid foam increase with decrease in cenosphere size and increase in relative density. On the other hand, the densification strain is almost invariant to the cenosphere size. All the above responses are correlated with relative density and materials parameters of HFs. This study demonstrates that cenosphere a thermal power plant waste can be used to get good quality of hybrid foam.
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effect of strain rate and relative density on compressive deformation behavior of aluminum cenosphere syntactic foam
2014Co-Authors: M D Goel, D P Mondal, M S Yadav, S K GuptaAbstract:Abstract The compressive deformation behavior of aluminum cenosphere syntactic foams of varying densities and cenosphere sizes have been studied at different strain rates (from 0.01/s to 10/s). The plateau stress, densification strain, energy absorption and strain rate sensitivity parameter as a function of relative density, strain rate and cenosphere size have been examined. Densification strain is found to be almost invariant to relative density, strain rate and cenosphere size. But, the plateau stress and energy absorption of syntactic foams are influenced by the relative density and cenosphere size. However, plateau stress is found to be almost invariant to the strain rate. The energy absorption is marginally higher in case of syntactic foam with coarser cenosphere at higher strain rate, whereas reverse is true at lower strain rate. This is attributed to the differences in deformation mechanism at different strain rates.
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titanium cenosphere syntactic foam with coarser cenosphere fabricated by powder metallurgy at lower compaction load
2014Co-Authors: D P Mondal, M D Goel, Jyotsna Dutta Majumdar, O P ModiAbstract:Abstract Titanium cenosphere syntactic foam of varying relative densities with coarse Cenospheres was developed through powder metallurgy route at lower compaction loads. The cold compaction load was varied in the range of 60 to 75 MPa to obtain the foams of different relative densities. A function of cold compaction load between crushing tendency of cenosphere and relative density was investigated. The compressive deformation behavior of these foams was studied, and empirical relationships among plateau stress, elastic modulus, densification strains and energy absorption are formulated considering their practical significance. The performance indices of the developed foam in comparison with dense titanium were studied and it was found that the foam is superior alternative to titanium for engineering applications.
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titanium cenosphere syntactic foam made through powder metallurgy route
2012Co-Authors: D P Mondal, Datta J Majumder, Anshul Badkul, Aruna Patel, Gaurav GuptaAbstract:Abstract Attempts have been made to use cenosphere as space holder to make Ti-cenosphere syntactic foam through powder metallurgy route. The cold compaction pressure was varied between 75 and 125 MPa in order to examine its effect on density, cenosphere crushing and strength of Ti-cenosphere foam. The cold compacted pallets were sintered at a temperature of 1100 °C for 2 h. Microstructural characteristics, density vis-a-vis porosity, compressive deformation behaviour and modulus of elasticity of the sintered samples were examined. It was noted that the porosity varies in the range of 51–70% depending on the pressure applied during cold compaction. A numerical model has been proposed to correlate density of foam with the extent of cenosphere crushing, density of cenosphere and density of titanium. The yield strength and modulus of elasticity of sintered foam samples are found to be a strong function of relative density.