TY  - JOUR
AU  - Obradović, Nina
AU  - Đorđević, Nataša
AU  - Filipović, Suzana
AU  - Marković, Smilja
AU  - Kosanović, Darko
AU  - Mitrić, Miodrag
AU  - Pavlović, Vladimir B.
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/999
AB  - Since cordierite, 2MgO center dot 2Al(2)O(3)center dot 5SiO(2) (MAS), is a very useful high-temperature ceramic material, it is important to decrease its sintering temperature. In order to accelerate the process of sintering, 5.00 mass% MoO3 was added to the starting mixtures. The mechanical activation of the starting mixtures was performed in a high-energy ball mill in time intervals from 0 to 160 min. After the activation, starting mixtures were sintered at 1300 A degrees C for 2 h. In order to determine the impact of mechanical activation on particle size distribution and powders morphology, the mechanically treated powders were characterized by a laser light-scattering particle size analyzer and scanning electron microscopy. The phase composition of the starting mixtures and sintered samples was analyzed by the X-ray diffraction method. In order to determine temperature intervals of chemical reactions and phase transitions, differential thermal analyses (DTA) and thermo-gravimetric analysis were used. Kissingers equation was employed to calculate apparent activation energies of various processes that occur within the system during heating. Based on the obtained DTA results, it was established that mechanical activation along with MoO3 additive has influence on sintering temperature which was decreased for more than 100 A degrees C, comparing to the literature data.
PB  - Springer
T2  - Journal of Thermal Analysis and Calorimetry
T1  - Reaction kinetics of mechanically activated cordierite-based ceramics studied via DTA
VL  - 124
IS  - 2
SP  - 667
EP  - 673
DO  - 10.1007/s10973-015-5132-9
ER  - 

@article{
author = "Obradović, Nina and Đorđević, Nataša and Filipović, Suzana and Marković, Smilja and Kosanović, Darko and Mitrić, Miodrag and Pavlović, Vladimir B.",
year = "2016",
abstract = "Since cordierite, 2MgO center dot 2Al(2)O(3)center dot 5SiO(2) (MAS), is a very useful high-temperature ceramic material, it is important to decrease its sintering temperature. In order to accelerate the process of sintering, 5.00 mass% MoO3 was added to the starting mixtures. The mechanical activation of the starting mixtures was performed in a high-energy ball mill in time intervals from 0 to 160 min. After the activation, starting mixtures were sintered at 1300 A degrees C for 2 h. In order to determine the impact of mechanical activation on particle size distribution and powders morphology, the mechanically treated powders were characterized by a laser light-scattering particle size analyzer and scanning electron microscopy. The phase composition of the starting mixtures and sintered samples was analyzed by the X-ray diffraction method. In order to determine temperature intervals of chemical reactions and phase transitions, differential thermal analyses (DTA) and thermo-gravimetric analysis were used. Kissingers equation was employed to calculate apparent activation energies of various processes that occur within the system during heating. Based on the obtained DTA results, it was established that mechanical activation along with MoO3 additive has influence on sintering temperature which was decreased for more than 100 A degrees C, comparing to the literature data.",
publisher = "Springer",
journal = "Journal of Thermal Analysis and Calorimetry",
title = "Reaction kinetics of mechanically activated cordierite-based ceramics studied via DTA",
volume = "124",
number = "2",
pages = "667-673",
doi = "10.1007/s10973-015-5132-9"
}

Obradović, N., Đorđević, N., Filipović, S., Marković, S., Kosanović, D., Mitrić, M.,& Pavlović, V. B.. (2016). Reaction kinetics of mechanically activated cordierite-based ceramics studied via DTA. in Journal of Thermal Analysis and Calorimetry
Springer., 124(2), 667-673.
https://doi.org/10.1007/s10973-015-5132-9

Obradović N, Đorđević N, Filipović S, Marković S, Kosanović D, Mitrić M, Pavlović VB. Reaction kinetics of mechanically activated cordierite-based ceramics studied via DTA. in Journal of Thermal Analysis and Calorimetry. 2016;124(2):667-673.
doi:10.1007/s10973-015-5132-9 .

Obradović, Nina, Đorđević, Nataša, Filipović, Suzana, Marković, Smilja, Kosanović, Darko, Mitrić, Miodrag, Pavlović, Vladimir B., "Reaction kinetics of mechanically activated cordierite-based ceramics studied via DTA" in Journal of Thermal Analysis and Calorimetry, 124, no. 2 (2016):667-673,
https://doi.org/10.1007/s10973-015-5132-9 . .

TY  - JOUR
AU  - Peleš, Adriana
AU  - Pavlović, Vera P.
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Mančić, Lidija
AU  - Krstić, Jelena
AU  - Mitrić, Miodrag
AU  - Vlahović, Branislav
AU  - Rašić, Goran
AU  - Kosanović, Darko
AU  - Pavlović, Vladimir B.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/735
AB  - Commercially available ZnO powder was mechanically activated in a planetary ball mill. In order to investigate the specific surface area, pore volume and microstructure of non-activated and mechanically activated ZnO powders the authors performed N-2 physisorption, SEM and TEM. Crystallite size and lattice microstrain were analyzed by X-ray diffraction method. XRD patterns indicate that peak intensities are getting lower and expend with activation time. The reduction in crystallite size and increasing of lattice microstrain with prolonged milling time were determined applying the Rietvelds method. The difference between non-activated and the activated powder has been also observed by X-ray photoelectron spectroscopy (XPS). XPS is used for investigating the chemical bonding of ZnO powder by analyzing the energy of photoelectrons. The lattice vibration spectra were obtained using Raman spectroscopy. In Raman spectra some changes along with atypical resonant scattering were noticed, which were caused by mechanical activation. (C) 2015 Published by Elsevier B.V.
T2  - Journal of Alloys and Compounds
T1  - Structural investigation of mechanically activated ZnO powder
VL  - 648
SP  - 971
EP  - 979
DO  - 10.1016/j.jallcom.2015.06.247
ER  - 

@article{
author = "Peleš, Adriana and Pavlović, Vera P. and Filipović, Suzana and Obradović, Nina and Mančić, Lidija and Krstić, Jelena and Mitrić, Miodrag and Vlahović, Branislav and Rašić, Goran and Kosanović, Darko and Pavlović, Vladimir B.",
year = "2015",
abstract = "Commercially available ZnO powder was mechanically activated in a planetary ball mill. In order to investigate the specific surface area, pore volume and microstructure of non-activated and mechanically activated ZnO powders the authors performed N-2 physisorption, SEM and TEM. Crystallite size and lattice microstrain were analyzed by X-ray diffraction method. XRD patterns indicate that peak intensities are getting lower and expend with activation time. The reduction in crystallite size and increasing of lattice microstrain with prolonged milling time were determined applying the Rietvelds method. The difference between non-activated and the activated powder has been also observed by X-ray photoelectron spectroscopy (XPS). XPS is used for investigating the chemical bonding of ZnO powder by analyzing the energy of photoelectrons. The lattice vibration spectra were obtained using Raman spectroscopy. In Raman spectra some changes along with atypical resonant scattering were noticed, which were caused by mechanical activation. (C) 2015 Published by Elsevier B.V.",
journal = "Journal of Alloys and Compounds",
title = "Structural investigation of mechanically activated ZnO powder",
volume = "648",
pages = "971-979",
doi = "10.1016/j.jallcom.2015.06.247"
}

Peleš, A., Pavlović, V. P., Filipović, S., Obradović, N., Mančić, L., Krstić, J., Mitrić, M., Vlahović, B., Rašić, G., Kosanović, D.,& Pavlović, V. B.. (2015). Structural investigation of mechanically activated ZnO powder. in Journal of Alloys and Compounds, 648, 971-979.
https://doi.org/10.1016/j.jallcom.2015.06.247

Peleš A, Pavlović VP, Filipović S, Obradović N, Mančić L, Krstić J, Mitrić M, Vlahović B, Rašić G, Kosanović D, Pavlović VB. Structural investigation of mechanically activated ZnO powder. in Journal of Alloys and Compounds. 2015;648:971-979.
doi:10.1016/j.jallcom.2015.06.247 .

Peleš, Adriana, Pavlović, Vera P., Filipović, Suzana, Obradović, Nina, Mančić, Lidija, Krstić, Jelena, Mitrić, Miodrag, Vlahović, Branislav, Rašić, Goran, Kosanović, Darko, Pavlović, Vladimir B., "Structural investigation of mechanically activated ZnO powder" in Journal of Alloys and Compounds, 648 (2015):971-979,
https://doi.org/10.1016/j.jallcom.2015.06.247 . .

TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Pavlović, Vladimir B.
AU  - Kosanović, Darko
AU  - Mitrić, Miodrag
AU  - Mitrovic, N.
AU  - Pouchly, V.
AU  - Kachlik, M.
AU  - Maca, Karel
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/373
AB  - In this article, the advantages of combined sintering in comparison with the conventional one, of mechanically activated magnesium titanate ceramic were investigated. The stoichiometric mixtures of MgO and TiO2 were mechano-chemically activated for 0, 10, 40, 80 and 160 minutes by ball milling and then isostatically pressed (CIP) to form green bodies. Conventional sintering was realized by heating up to 1400 degrees C and hold for 30 minutes in air atmosphere. Resulting ceramic samples with closed porosity were post-sintered by pressure assisted technique Hot Isostatic Pressing (HIP) at 1280 degrees C/3h in argon atmosphere with a pressure of 200 MPa. The best results were observed in the case of samples post-sintered by HIP, when single-phase MgTiO3 samples with relative density of 96% were prepared.
T2  - Science of Sintering
T1  - Advantages of Combined Sintering Compared to Conventional Sintering of Mechanically Activated Magnesium Titanate
VL  - 46
IS  - 3
SP  - 283
EP  - 290
DO  - 10.2298/SOS1403283F
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Pavlović, Vladimir B. and Kosanović, Darko and Mitrić, Miodrag and Mitrovic, N. and Pouchly, V. and Kachlik, M. and Maca, Karel",
year = "2014",
abstract = "In this article, the advantages of combined sintering in comparison with the conventional one, of mechanically activated magnesium titanate ceramic were investigated. The stoichiometric mixtures of MgO and TiO2 were mechano-chemically activated for 0, 10, 40, 80 and 160 minutes by ball milling and then isostatically pressed (CIP) to form green bodies. Conventional sintering was realized by heating up to 1400 degrees C and hold for 30 minutes in air atmosphere. Resulting ceramic samples with closed porosity were post-sintered by pressure assisted technique Hot Isostatic Pressing (HIP) at 1280 degrees C/3h in argon atmosphere with a pressure of 200 MPa. The best results were observed in the case of samples post-sintered by HIP, when single-phase MgTiO3 samples with relative density of 96% were prepared.",
journal = "Science of Sintering",
title = "Advantages of Combined Sintering Compared to Conventional Sintering of Mechanically Activated Magnesium Titanate",
volume = "46",
number = "3",
pages = "283-290",
doi = "10.2298/SOS1403283F"
}

Filipović, S., Obradović, N., Pavlović, V. B., Kosanović, D., Mitrić, M., Mitrovic, N., Pouchly, V., Kachlik, M.,& Maca, K.. (2014). Advantages of Combined Sintering Compared to Conventional Sintering of Mechanically Activated Magnesium Titanate. in Science of Sintering, 46(3), 283-290.
https://doi.org/10.2298/SOS1403283F

Filipović S, Obradović N, Pavlović VB, Kosanović D, Mitrić M, Mitrovic N, Pouchly V, Kachlik M, Maca K. Advantages of Combined Sintering Compared to Conventional Sintering of Mechanically Activated Magnesium Titanate. in Science of Sintering. 2014;46(3):283-290.
doi:10.2298/SOS1403283F .

Filipović, Suzana, Obradović, Nina, Pavlović, Vladimir B., Kosanović, Darko, Mitrić, Miodrag, Mitrovic, N., Pouchly, V., Kachlik, M., Maca, Karel, "Advantages of Combined Sintering Compared to Conventional Sintering of Mechanically Activated Magnesium Titanate" in Science of Sintering, 46, no. 3 (2014):283-290,
https://doi.org/10.2298/SOS1403283F . .

TY  - JOUR
AU  - Dordevic, N.
AU  - Obradović, Nina
AU  - Kosanović, Darko
AU  - Mitrić, Miodrag
AU  - Pavlović, Vera P.
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/374
AB  - Cordierite (MAS) is difficult to sinter because of the very narrow sintering temperature range (1300-1400 degrees C). Because a low temperature process is desirable, it is necessary to find functional ads which can allow easier sintering process at lower temperature. The influence of MoO3 on the preparation process of cordierite ceramics was investigated. 2MgO-2Al(2)O(3)-5SiO(2) was researched by sintering followed binary systems: MgO/MoO3, Al2O3/MoO3 and SiO2/MoO3 (all sintered at 850 degrees C and 1100 degrees C, sintering time 2h). Composition of these systems was 80 mass% of oxide and 20 mass% MoO3. The effects of sintering, the composition and morphology were followed by X-ray diffraction and SEM microscopy. It has been found that MoO3, beside liquid phase, forms intermediary unstable compounds with MgO and Al2O3, which is the significance information for further research. MAS ceramics were sintered with 20 mass% MoO3 at 1100 degrees C, 1200 degrees C and 1300 degrees C, during 2h.
T2  - Science of Sintering
T1  - Sintering of Cordierite in the Presence of MoO3 and Crystallization Analysis
VL  - 46
IS  - 3
SP  - 307
EP  - 313
DO  - 10.2298/SOS1403307D
ER  - 

@article{
author = "Dordevic, N. and Obradović, Nina and Kosanović, Darko and Mitrić, Miodrag and Pavlović, Vera P.",
year = "2014",
abstract = "Cordierite (MAS) is difficult to sinter because of the very narrow sintering temperature range (1300-1400 degrees C). Because a low temperature process is desirable, it is necessary to find functional ads which can allow easier sintering process at lower temperature. The influence of MoO3 on the preparation process of cordierite ceramics was investigated. 2MgO-2Al(2)O(3)-5SiO(2) was researched by sintering followed binary systems: MgO/MoO3, Al2O3/MoO3 and SiO2/MoO3 (all sintered at 850 degrees C and 1100 degrees C, sintering time 2h). Composition of these systems was 80 mass% of oxide and 20 mass% MoO3. The effects of sintering, the composition and morphology were followed by X-ray diffraction and SEM microscopy. It has been found that MoO3, beside liquid phase, forms intermediary unstable compounds with MgO and Al2O3, which is the significance information for further research. MAS ceramics were sintered with 20 mass% MoO3 at 1100 degrees C, 1200 degrees C and 1300 degrees C, during 2h.",
journal = "Science of Sintering",
title = "Sintering of Cordierite in the Presence of MoO3 and Crystallization Analysis",
volume = "46",
number = "3",
pages = "307-313",
doi = "10.2298/SOS1403307D"
}

Dordevic, N., Obradović, N., Kosanović, D., Mitrić, M.,& Pavlović, V. P.. (2014). Sintering of Cordierite in the Presence of MoO3 and Crystallization Analysis. in Science of Sintering, 46(3), 307-313.
https://doi.org/10.2298/SOS1403307D

Dordevic N, Obradović N, Kosanović D, Mitrić M, Pavlović VP. Sintering of Cordierite in the Presence of MoO3 and Crystallization Analysis. in Science of Sintering. 2014;46(3):307-313.
doi:10.2298/SOS1403307D .

Dordevic, N., Obradović, Nina, Kosanović, Darko, Mitrić, Miodrag, Pavlović, Vera P., "Sintering of Cordierite in the Presence of MoO3 and Crystallization Analysis" in Science of Sintering, 46, no. 3 (2014):307-313,
https://doi.org/10.2298/SOS1403307D . .

TY  - JOUR
AU  - Obradović, Nina
AU  - Dordevic, N.
AU  - Filipović, Suzana
AU  - Nikolic, N.
AU  - Kosanović, Darko
AU  - Mitrić, Miodrag
AU  - Marković, Smilja
AU  - Pavlović, Vladimir B.
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4702
AB  - Due to its outstanding electrical characteristics, such as the low temperature expansion coefficient, low dielectric constant and good mechanical properties, cordierite, 2MgO center dot 2Al(2)O(3)center dot 5SiO(2), is a very attractive high-temperature ceramic material. In order to accelerate the process of sintering, 2.50 mass% Bi2O3 has been added to the starting mixtures. Liquid phase sintering caused by the presence of bismuth-oxide lowers the temperature of cordierite formation. The mechanical activation of the starting mixtures (0-56 min in vibro-mill) additionally lowers sintering temperatures. The sintering process was performed at 1200, 1300, 1350 and 1400 degrees C, for 2 h. The particle size analysis (PSA) was employed in order to determine the changes in the particle size of the mechanically treated powders. The phase composition of the starting powders and sintered materials was analyzed by the X-ray diffraction method. Furthermore, scanning electron microscopy (SEM) was used in the analysis of the powder morphology. (C) 2011 Elsevier B.V. All rights reserved.
T2  - Powder Technology
T1  - Influence of mechanochemical activation on the sintering of cordierite ceramics in the presence of Bi2O3 as a functional additive
VL  - 218
SP  - 157
EP  - 161
DO  - 10.1016/j.powtec.2011.12.012
ER  - 

@article{
author = "Obradović, Nina and Dordevic, N. and Filipović, Suzana and Nikolic, N. and Kosanović, Darko and Mitrić, Miodrag and Marković, Smilja and Pavlović, Vladimir B.",
year = "2012",
abstract = "Due to its outstanding electrical characteristics, such as the low temperature expansion coefficient, low dielectric constant and good mechanical properties, cordierite, 2MgO center dot 2Al(2)O(3)center dot 5SiO(2), is a very attractive high-temperature ceramic material. In order to accelerate the process of sintering, 2.50 mass% Bi2O3 has been added to the starting mixtures. Liquid phase sintering caused by the presence of bismuth-oxide lowers the temperature of cordierite formation. The mechanical activation of the starting mixtures (0-56 min in vibro-mill) additionally lowers sintering temperatures. The sintering process was performed at 1200, 1300, 1350 and 1400 degrees C, for 2 h. The particle size analysis (PSA) was employed in order to determine the changes in the particle size of the mechanically treated powders. The phase composition of the starting powders and sintered materials was analyzed by the X-ray diffraction method. Furthermore, scanning electron microscopy (SEM) was used in the analysis of the powder morphology. (C) 2011 Elsevier B.V. All rights reserved.",
journal = "Powder Technology",
title = "Influence of mechanochemical activation on the sintering of cordierite ceramics in the presence of Bi2O3 as a functional additive",
volume = "218",
pages = "157-161",
doi = "10.1016/j.powtec.2011.12.012"
}

Obradović, N., Dordevic, N., Filipović, S., Nikolic, N., Kosanović, D., Mitrić, M., Marković, S.,& Pavlović, V. B.. (2012). Influence of mechanochemical activation on the sintering of cordierite ceramics in the presence of Bi2O3 as a functional additive. in Powder Technology, 218, 157-161.
https://doi.org/10.1016/j.powtec.2011.12.012

Obradović N, Dordevic N, Filipović S, Nikolic N, Kosanović D, Mitrić M, Marković S, Pavlović VB. Influence of mechanochemical activation on the sintering of cordierite ceramics in the presence of Bi2O3 as a functional additive. in Powder Technology. 2012;218:157-161.
doi:10.1016/j.powtec.2011.12.012 .

Obradović, Nina, Dordevic, N., Filipović, Suzana, Nikolic, N., Kosanović, Darko, Mitrić, Miodrag, Marković, Smilja, Pavlović, Vladimir B., "Influence of mechanochemical activation on the sintering of cordierite ceramics in the presence of Bi2O3 as a functional additive" in Powder Technology, 218 (2012):157-161,
https://doi.org/10.1016/j.powtec.2011.12.012 . .

TY  - JOUR
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Mitrić, Miodrag
AU  - Pavlović, Vladimir B.
AU  - Paunović, Verica G.
AU  - Kosanović, Darko
AU  - Balac, I.
AU  - Ristic, M. M.
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4809
AB  - Starting mixtures of BaCO3, ZnO, and TiO2 powders are mechanically activated in a planetary ball mill for various periods of time. The powders obtained are sintered isothermally at 1100A degrees C for 120 min. Non-isothermal sintering process is followed by measurements with a sensitive dilatometer, as well. Results of microstructure characterization using SEM analyses along with DTA analyses are provided. These results are correlated with the values of electric resistivity, capacitance, and loss tangent of the samples, and it is found that with increasing milling time, the increase in values of electrical properties is noticed.
T2  - Powder Metallurgy and Metal Ceramics
T1  - Influence of mechanical activation on electrical properties of barium-zinc-titanate ceramics sintered at 1100A degrees C
VL  - 50
IS  - 11-12
SP  - 714
EP  - 718
DO  - 10.1007/s11106-012-9380-y
ER  - 

@article{
author = "Obradović, Nina and Filipović, Suzana and Mitrić, Miodrag and Pavlović, Vladimir B. and Paunović, Verica G. and Kosanović, Darko and Balac, I. and Ristic, M. M.",
year = "2012",
abstract = "Starting mixtures of BaCO3, ZnO, and TiO2 powders are mechanically activated in a planetary ball mill for various periods of time. The powders obtained are sintered isothermally at 1100A degrees C for 120 min. Non-isothermal sintering process is followed by measurements with a sensitive dilatometer, as well. Results of microstructure characterization using SEM analyses along with DTA analyses are provided. These results are correlated with the values of electric resistivity, capacitance, and loss tangent of the samples, and it is found that with increasing milling time, the increase in values of electrical properties is noticed.",
journal = "Powder Metallurgy and Metal Ceramics",
title = "Influence of mechanical activation on electrical properties of barium-zinc-titanate ceramics sintered at 1100A degrees C",
volume = "50",
number = "11-12",
pages = "714-718",
doi = "10.1007/s11106-012-9380-y"
}

Obradović, N., Filipović, S., Mitrić, M., Pavlović, V. B., Paunović, V. G., Kosanović, D., Balac, I.,& Ristic, M. M.. (2012). Influence of mechanical activation on electrical properties of barium-zinc-titanate ceramics sintered at 1100A degrees C. in Powder Metallurgy and Metal Ceramics, 50(11-12), 714-718.
https://doi.org/10.1007/s11106-012-9380-y

Obradović N, Filipović S, Mitrić M, Pavlović VB, Paunović VG, Kosanović D, Balac I, Ristic MM. Influence of mechanical activation on electrical properties of barium-zinc-titanate ceramics sintered at 1100A degrees C. in Powder Metallurgy and Metal Ceramics. 2012;50(11-12):714-718.
doi:10.1007/s11106-012-9380-y .

Obradović, Nina, Filipović, Suzana, Mitrić, Miodrag, Pavlović, Vladimir B., Paunović, Verica G., Kosanović, Darko, Balac, I., Ristic, M. M., "Influence of mechanical activation on electrical properties of barium-zinc-titanate ceramics sintered at 1100A degrees C" in Powder Metallurgy and Metal Ceramics, 50, no. 11-12 (2012):714-718,
https://doi.org/10.1007/s11106-012-9380-y . .