TY  - JOUR
AU  - Ćosović, Vladan
AU  - Pavlović, Miroslav M.
AU  - Cosovic, A.
AU  - Vulić, Predrag
AU  - Premović, Milena
AU  - Živković, Dragana
AU  - Talijan, Nadežda M.
PY  - 2013
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1186
AB  - High energy ball milling was used in order to improve dispersion of metal oxide in Ag-SnO2 electrical contact materials. The processed Ag-SnO2 (92:8) and Ag-SnO2In2O3 (87.8:9.30:2.9) powder mixtures were subsequently consolidated to bulk solid pieces by conventional powder metallurgy method. The characterization of the prepared samples included microstructural analysis by XRD and SEM, as well as measurements of physical properties such as density, hardness and electrical conductivity. The results of X-Ray analysis point to reduction of crystallite size after milling of about ten times. Microstructures of sintered Ag-SnO2 and Ag-SnO2 In2O3 materials display very fine dispersion of the oxide components in silver matrix. Somewhat higher uniformity was obtained for Ag-SnO2 In2O3 material which was illustrated by results of SEM analysis and more consistent microhardness values. The obtained values of studied physical properties were found to be in accordance with observed higher dispersion of metal oxide particles and comparable to properties of commercial electrical contact materials of this type.
AB  - Metoda visokoenergetskog mehaničkog mlevenja je primenjena za pripremu elektrokontaktnih materijala na bazi Ag-SnO2 sa ciljem postizanja visokog stepena disperzije čestica metalnih oksida u srebrnoj matrici. Smeše prahova sastava Ag- SnO2 (92:8) i Ag-SnO2In2O3 (87.8:9.30:2.9) su posle mlevenja procesuirane konvencionalnim tehnikama metalurgije praha. Karakterizacija sinterovanih uzoraka obuhvatila je mikrostrukturnu analizu (XRD, SEM) kao i merenje važnijih fizičkih svojstava: gustina, tvrdoća i električna provodljivost. Rezultati XRD analize su pokazali značajno smanjenje veličine kristalita od oko deset puta. Mikrostrukturna analiza sinterovanih materijala ukazala je na veoma finu i uniformnu disperziju oksidnih komponenti u srebrnoj matrici. SEM mikrofotografije takođe pokazuju veću uniformnost mikrostrukture uzorka Ag-SnO2In2O3 što potvrđuju i ujednačenije vrednosti mikrotvrdoće dobijene za ovaj materijal. Izmerene vrednosti analiziranih fizičkih svojstava su u saglasnosti sa postignutim većim stepenom disperzije čestica metalnih oksida u srebrnoj matrici i uporedive su sa svojstvima komercijalnih elektrokontaktnih materijala ovog tipa.
PB  - International Institute for the Science of Sintering, Beograd
T2  - Science of Sintering
T1  - Microstructure refinement and physical properties of Ag-SnO2 based contact materials prepared by high-energy ball milling
VL  - 45
IS  - 2
SP  - 173
EP  - 180
DO  - 10.2298/SOS1302173C
ER  - 

@article{
author = "Ćosović, Vladan and Pavlović, Miroslav M. and Cosovic, A. and Vulić, Predrag and Premović, Milena and Živković, Dragana and Talijan, Nadežda M.",
year = "2013",
abstract = "High energy ball milling was used in order to improve dispersion of metal oxide in Ag-SnO2 electrical contact materials. The processed Ag-SnO2 (92:8) and Ag-SnO2In2O3 (87.8:9.30:2.9) powder mixtures were subsequently consolidated to bulk solid pieces by conventional powder metallurgy method. The characterization of the prepared samples included microstructural analysis by XRD and SEM, as well as measurements of physical properties such as density, hardness and electrical conductivity. The results of X-Ray analysis point to reduction of crystallite size after milling of about ten times. Microstructures of sintered Ag-SnO2 and Ag-SnO2 In2O3 materials display very fine dispersion of the oxide components in silver matrix. Somewhat higher uniformity was obtained for Ag-SnO2 In2O3 material which was illustrated by results of SEM analysis and more consistent microhardness values. The obtained values of studied physical properties were found to be in accordance with observed higher dispersion of metal oxide particles and comparable to properties of commercial electrical contact materials of this type., Metoda visokoenergetskog mehaničkog mlevenja je primenjena za pripremu elektrokontaktnih materijala na bazi Ag-SnO2 sa ciljem postizanja visokog stepena disperzije čestica metalnih oksida u srebrnoj matrici. Smeše prahova sastava Ag- SnO2 (92:8) i Ag-SnO2In2O3 (87.8:9.30:2.9) su posle mlevenja procesuirane konvencionalnim tehnikama metalurgije praha. Karakterizacija sinterovanih uzoraka obuhvatila je mikrostrukturnu analizu (XRD, SEM) kao i merenje važnijih fizičkih svojstava: gustina, tvrdoća i električna provodljivost. Rezultati XRD analize su pokazali značajno smanjenje veličine kristalita od oko deset puta. Mikrostrukturna analiza sinterovanih materijala ukazala je na veoma finu i uniformnu disperziju oksidnih komponenti u srebrnoj matrici. SEM mikrofotografije takođe pokazuju veću uniformnost mikrostrukture uzorka Ag-SnO2In2O3 što potvrđuju i ujednačenije vrednosti mikrotvrdoće dobijene za ovaj materijal. Izmerene vrednosti analiziranih fizičkih svojstava su u saglasnosti sa postignutim većim stepenom disperzije čestica metalnih oksida u srebrnoj matrici i uporedive su sa svojstvima komercijalnih elektrokontaktnih materijala ovog tipa.",
publisher = "International Institute for the Science of Sintering, Beograd",
journal = "Science of Sintering",
title = "Microstructure refinement and physical properties of Ag-SnO2 based contact materials prepared by high-energy ball milling",
volume = "45",
number = "2",
pages = "173-180",
doi = "10.2298/SOS1302173C"
}

Ćosović, V., Pavlović, M. M., Cosovic, A., Vulić, P., Premović, M., Živković, D.,& Talijan, N. M.. (2013). Microstructure refinement and physical properties of Ag-SnO2 based contact materials prepared by high-energy ball milling. in Science of Sintering
International Institute for the Science of Sintering, Beograd., 45(2), 173-180.
https://doi.org/10.2298/SOS1302173C

Ćosović V, Pavlović MM, Cosovic A, Vulić P, Premović M, Živković D, Talijan NM. Microstructure refinement and physical properties of Ag-SnO2 based contact materials prepared by high-energy ball milling. in Science of Sintering. 2013;45(2):173-180.
doi:10.2298/SOS1302173C .

Ćosović, Vladan, Pavlović, Miroslav M., Cosovic, A., Vulić, Predrag, Premović, Milena, Živković, Dragana, Talijan, Nadežda M., "Microstructure refinement and physical properties of Ag-SnO2 based contact materials prepared by high-energy ball milling" in Science of Sintering, 45, no. 2 (2013):173-180,
https://doi.org/10.2298/SOS1302173C . .

TY  - JOUR
AU  - Cosovic, A.
AU  - Ćosović, Vladan
AU  - Žak, Tomas
AU  - David, B.
AU  - Talijan, Nadežda M.
PY  - 2013
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1244
AB  - Nanosize NiFe2O4 was prepared by template method and precipitation process using same starting materials. The use of soluble starch in both synthesis routes was investigated. The amount of the used precipitating agent (Na2CO3) for the precipitation approach was selected according to two adopted scenarios based on theoretical and average yield of possible side reaction expressed by the degree of substitution (DS). The results of SEM microstructural analysis of the prepared Ni-ferrite powders demonstrate evident influence of the applied preparation method whereas high-magnification FE-SEM images show very similar fine-grained structures characterized by different size of particles. According to the results of XRD analysis, the obtained ferrite powders exhibit only slight differences in phase composition with calculated crystallite size for template sample d(XRD) = 36 nm and for the both precipitation route samples d(XRD) = 21 nm. Additional sample characterization using Fe-57 Mossbauer spectroscopy supports the findings of the microstructural and XRD analysis. The "clearest" spectrum was obtained for the template sample while the strongest influence of nanocrystalline component was observed for the sample prepared with maximal amount of precipitation agent (DS=3). The room temperature magnetic hysteresis loops, recorded using vibrating sample magnetometer (VSM), are very similar and exhibit characteristic shape with values of magnetic properties within expected range for this type of material.
PB  - Technical Faculty, Bor
T2  - Journal of Mining and Metallurgy B: Metallurgy
T1  - STRUCTURE AND PROPERTIES OF NANOSIZE NiFe2O4 PREPARED BY TEMPLATE AND PRECIPITATION METHODS
VL  - 49
IS  - 3
SP  - 271
EP  - 277
DO  - 10.2298/JMMB130313021C
ER  - 

@article{
author = "Cosovic, A. and Ćosović, Vladan and Žak, Tomas and David, B. and Talijan, Nadežda M.",
year = "2013",
abstract = "Nanosize NiFe2O4 was prepared by template method and precipitation process using same starting materials. The use of soluble starch in both synthesis routes was investigated. The amount of the used precipitating agent (Na2CO3) for the precipitation approach was selected according to two adopted scenarios based on theoretical and average yield of possible side reaction expressed by the degree of substitution (DS). The results of SEM microstructural analysis of the prepared Ni-ferrite powders demonstrate evident influence of the applied preparation method whereas high-magnification FE-SEM images show very similar fine-grained structures characterized by different size of particles. According to the results of XRD analysis, the obtained ferrite powders exhibit only slight differences in phase composition with calculated crystallite size for template sample d(XRD) = 36 nm and for the both precipitation route samples d(XRD) = 21 nm. Additional sample characterization using Fe-57 Mossbauer spectroscopy supports the findings of the microstructural and XRD analysis. The "clearest" spectrum was obtained for the template sample while the strongest influence of nanocrystalline component was observed for the sample prepared with maximal amount of precipitation agent (DS=3). The room temperature magnetic hysteresis loops, recorded using vibrating sample magnetometer (VSM), are very similar and exhibit characteristic shape with values of magnetic properties within expected range for this type of material.",
publisher = "Technical Faculty, Bor",
journal = "Journal of Mining and Metallurgy B: Metallurgy",
title = "STRUCTURE AND PROPERTIES OF NANOSIZE NiFe2O4 PREPARED BY TEMPLATE AND PRECIPITATION METHODS",
volume = "49",
number = "3",
pages = "271-277",
doi = "10.2298/JMMB130313021C"
}

Cosovic, A., Ćosović, V., Žak, T., David, B.,& Talijan, N. M.. (2013). STRUCTURE AND PROPERTIES OF NANOSIZE NiFe2O4 PREPARED BY TEMPLATE AND PRECIPITATION METHODS. in Journal of Mining and Metallurgy B: Metallurgy
Technical Faculty, Bor., 49(3), 271-277.
https://doi.org/10.2298/JMMB130313021C

Cosovic A, Ćosović V, Žak T, David B, Talijan NM. STRUCTURE AND PROPERTIES OF NANOSIZE NiFe2O4 PREPARED BY TEMPLATE AND PRECIPITATION METHODS. in Journal of Mining and Metallurgy B: Metallurgy. 2013;49(3):271-277.
doi:10.2298/JMMB130313021C .

Cosovic, A., Ćosović, Vladan, Žak, Tomas, David, B., Talijan, Nadežda M., "STRUCTURE AND PROPERTIES OF NANOSIZE NiFe2O4 PREPARED BY TEMPLATE AND PRECIPITATION METHODS" in Journal of Mining and Metallurgy B: Metallurgy, 49, no. 3 (2013):271-277,
https://doi.org/10.2298/JMMB130313021C . .

TY  - JOUR
AU  - Žak, Tomas
AU  - Ćosović, Vladan
AU  - Cosovic, A.
AU  - David, B.
AU  - Talijan, Nadežda M.
AU  - Živković, Dragana
PY  - 2012
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1069
AB  - Magnetic NiFe2O4 structure formation was studied through structural, compositional and magnetic characterization of obtained reaction products of a simple, high yielding and low-cost solid-state reaction. Initial annealing of the starting oxides mixture at 700 degrees C did not allow us to observe formation of the desired magnetic phase. In contrast, subsequent thermomagnetic measurements up to 800 degrees C indicated the considerable increase of the magnetic moment, which can be reasonably assigned to the changes in phase composition and formation of magnetic NiFe2O4 structure during the heating cycle of measurements. Nanosized NiFe2O4 phase formation has been confirmed by the following XRD and MS phase analyses and its nanocrystalline structure by XRD and SEM/TEM techniques. The obtained hysteresis loop taken after TM measurements suggest the increased volume of magnetically active material and thus additionally support the previous findings.
PB  - International Institute for the Science of Sintering, Beograd
T2  - Science of Sintering
T1  - Formation of Magnetic Microstructure of the Nanosized NiFe2O4 Synthesized Via Solid-State Reaction
VL  - 44
IS  - 1
SP  - 103
EP  - 112
DO  - 10.2298/SOS1201103Z
ER  - 

@article{
author = "Žak, Tomas and Ćosović, Vladan and Cosovic, A. and David, B. and Talijan, Nadežda M. and Živković, Dragana",
year = "2012",
abstract = "Magnetic NiFe2O4 structure formation was studied through structural, compositional and magnetic characterization of obtained reaction products of a simple, high yielding and low-cost solid-state reaction. Initial annealing of the starting oxides mixture at 700 degrees C did not allow us to observe formation of the desired magnetic phase. In contrast, subsequent thermomagnetic measurements up to 800 degrees C indicated the considerable increase of the magnetic moment, which can be reasonably assigned to the changes in phase composition and formation of magnetic NiFe2O4 structure during the heating cycle of measurements. Nanosized NiFe2O4 phase formation has been confirmed by the following XRD and MS phase analyses and its nanocrystalline structure by XRD and SEM/TEM techniques. The obtained hysteresis loop taken after TM measurements suggest the increased volume of magnetically active material and thus additionally support the previous findings.",
publisher = "International Institute for the Science of Sintering, Beograd",
journal = "Science of Sintering",
title = "Formation of Magnetic Microstructure of the Nanosized NiFe2O4 Synthesized Via Solid-State Reaction",
volume = "44",
number = "1",
pages = "103-112",
doi = "10.2298/SOS1201103Z"
}

Žak, T., Ćosović, V., Cosovic, A., David, B., Talijan, N. M.,& Živković, D.. (2012). Formation of Magnetic Microstructure of the Nanosized NiFe2O4 Synthesized Via Solid-State Reaction. in Science of Sintering
International Institute for the Science of Sintering, Beograd., 44(1), 103-112.
https://doi.org/10.2298/SOS1201103Z

Žak T, Ćosović V, Cosovic A, David B, Talijan NM, Živković D. Formation of Magnetic Microstructure of the Nanosized NiFe2O4 Synthesized Via Solid-State Reaction. in Science of Sintering. 2012;44(1):103-112.
doi:10.2298/SOS1201103Z .

Žak, Tomas, Ćosović, Vladan, Cosovic, A., David, B., Talijan, Nadežda M., Živković, Dragana, "Formation of Magnetic Microstructure of the Nanosized NiFe2O4 Synthesized Via Solid-State Reaction" in Science of Sintering, 44, no. 1 (2012):103-112,
https://doi.org/10.2298/SOS1201103Z . .

TY  - JOUR
AU  - Ćosović, Vladan
AU  - Cosovic, A.
AU  - Talijan, Nadežda M.
AU  - Živković, Dragana
AU  - Zivkovic, Z.
PY  - 2012
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1068
AB  - The article surveys current state of the art and challenges in the development of the electrical contact materials in the light of the EU Directive on Restriction of Hazardous Substances (RoHS). The focus was placed on widely used silver-cadmium alloys. According to this directive, as of July 1, 2006, use of six hazardous materials, including cadmium, are restricted for applicable electrical and electronic products intended for the EU market. In contrast, traditionally preferred material for production of electrical contacts is Ag-CdO, due to its outstanding functional properties. These conflicting interests result in present state where RoHS directive has not yet been implemented in its original form and has undergone numerous amendments and exceptions regarding the use of cadmium. Main reason for this seems to be the unrealistic time frame imposed by legislation. Although, significant effort has been put into research and development of alternative materials, there are still cases where adequate replacement materials had not been found. Therefore, importance of synchronicity between legislation and technological progress i.e. communication between legislative administration and industry and academia is brought to light as well as some common issues that may arise with an introduction of new replacement materials or product modification.
PB  - International Institute for the Science of Sintering, Beograd
T2  - Science of Sintering
T1  - State of the Art and Challenges in Development of Electrical Contact Materials in the Light of the RoHS Directive
VL  - 44
IS  - 2
SP  - 245
EP  - 253
DO  - 10.2298/SOS1202135C
ER  - 

@article{
author = "Ćosović, Vladan and Cosovic, A. and Talijan, Nadežda M. and Živković, Dragana and Zivkovic, Z.",
year = "2012",
abstract = "The article surveys current state of the art and challenges in the development of the electrical contact materials in the light of the EU Directive on Restriction of Hazardous Substances (RoHS). The focus was placed on widely used silver-cadmium alloys. According to this directive, as of July 1, 2006, use of six hazardous materials, including cadmium, are restricted for applicable electrical and electronic products intended for the EU market. In contrast, traditionally preferred material for production of electrical contacts is Ag-CdO, due to its outstanding functional properties. These conflicting interests result in present state where RoHS directive has not yet been implemented in its original form and has undergone numerous amendments and exceptions regarding the use of cadmium. Main reason for this seems to be the unrealistic time frame imposed by legislation. Although, significant effort has been put into research and development of alternative materials, there are still cases where adequate replacement materials had not been found. Therefore, importance of synchronicity between legislation and technological progress i.e. communication between legislative administration and industry and academia is brought to light as well as some common issues that may arise with an introduction of new replacement materials or product modification.",
publisher = "International Institute for the Science of Sintering, Beograd",
journal = "Science of Sintering",
title = "State of the Art and Challenges in Development of Electrical Contact Materials in the Light of the RoHS Directive",
volume = "44",
number = "2",
pages = "245-253",
doi = "10.2298/SOS1202135C"
}

Ćosović, V., Cosovic, A., Talijan, N. M., Živković, D.,& Zivkovic, Z.. (2012). State of the Art and Challenges in Development of Electrical Contact Materials in the Light of the RoHS Directive. in Science of Sintering
International Institute for the Science of Sintering, Beograd., 44(2), 245-253.
https://doi.org/10.2298/SOS1202135C

Ćosović V, Cosovic A, Talijan NM, Živković D, Zivkovic Z. State of the Art and Challenges in Development of Electrical Contact Materials in the Light of the RoHS Directive. in Science of Sintering. 2012;44(2):245-253.
doi:10.2298/SOS1202135C .

Ćosović, Vladan, Cosovic, A., Talijan, Nadežda M., Živković, Dragana, Zivkovic, Z., "State of the Art and Challenges in Development of Electrical Contact Materials in the Light of the RoHS Directive" in Science of Sintering, 44, no. 2 (2012):245-253,
https://doi.org/10.2298/SOS1202135C . .