TY  - JOUR
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Sedmak, Aleksandar
AU  - Radović, Nenad
AU  - Međo, Bojan
AU  - Mrdak, Mihailo
AU  - Bajić, Darko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6008
AB  - This paper deals with analysis and comparison of the equivalent plastic strain and temperature fields in the aluminium alloy 2024 T3 welded joint, with macro/microstructure appearance and hardness profile. In the alloys hardened by heat treatment, grain size and particle size of the precipitate are functions of equivalent plastic strain, strain rate and temperature. By analyzing the equivalent plastic strain fields and temperature fields it is possible, to some extent, to capture the effect of welding parameters and thermo-mechanical conditions on grain structure, and therefore hardness and strength in the welded joint. A coupled thermo-mechanical model is applied to study the material behaviour during the linear welding stage of friction stir welding (FSW). Three-dimensional finite element (FE) model has been created in ABAQUS/Explicit software using the Johnson-Cook material law. The values of thermo-mechanical quantities during the welding stage are obtained from the numerical model and shown as distributions across the joint. The obtained values of these quantities are related to the microstructure of the joint zones and hardness distribution, and this relation is discussed.
PB  - VINČA Institute of Nuclear Sciences
T2  - Thermal Science
T1  - Influence of temperature and plastic deformation on AA2024 T3 friction stir welded joint microstructure
EP  - 320
IS  - 1A
SP  - 311
VL  - 27
DO  - 10.2298/TSCI210216186V
ER  - 

@article{
author = "Veljić, Darko and Rakin, Marko and Sedmak, Aleksandar and Radović, Nenad and Međo, Bojan and Mrdak, Mihailo and Bajić, Darko",
year = "2023",
abstract = "This paper deals with analysis and comparison of the equivalent plastic strain and temperature fields in the aluminium alloy 2024 T3 welded joint, with macro/microstructure appearance and hardness profile. In the alloys hardened by heat treatment, grain size and particle size of the precipitate are functions of equivalent plastic strain, strain rate and temperature. By analyzing the equivalent plastic strain fields and temperature fields it is possible, to some extent, to capture the effect of welding parameters and thermo-mechanical conditions on grain structure, and therefore hardness and strength in the welded joint. A coupled thermo-mechanical model is applied to study the material behaviour during the linear welding stage of friction stir welding (FSW). Three-dimensional finite element (FE) model has been created in ABAQUS/Explicit software using the Johnson-Cook material law. The values of thermo-mechanical quantities during the welding stage are obtained from the numerical model and shown as distributions across the joint. The obtained values of these quantities are related to the microstructure of the joint zones and hardness distribution, and this relation is discussed.",
publisher = "VINČA Institute of Nuclear Sciences",
journal = "Thermal Science",
title = "Influence of temperature and plastic deformation on AA2024 T3 friction stir welded joint microstructure",
pages = "320-311",
number = "1A",
volume = "27",
doi = "10.2298/TSCI210216186V"
}

Veljić, D., Rakin, M., Sedmak, A., Radović, N., Međo, B., Mrdak, M.,& Bajić, D.. (2023). Influence of temperature and plastic deformation on AA2024 T3 friction stir welded joint microstructure. in Thermal Science
VINČA Institute of Nuclear Sciences., 27(1A), 311-320.
https://doi.org/10.2298/TSCI210216186V

Veljić D, Rakin M, Sedmak A, Radović N, Međo B, Mrdak M, Bajić D. Influence of temperature and plastic deformation on AA2024 T3 friction stir welded joint microstructure. in Thermal Science. 2023;27(1A):311-320.
doi:10.2298/TSCI210216186V .

Veljić, Darko, Rakin, Marko, Sedmak, Aleksandar, Radović, Nenad, Međo, Bojan, Mrdak, Mihailo, Bajić, Darko, "Influence of temperature and plastic deformation on AA2024 T3 friction stir welded joint microstructure" in Thermal Science, 27, no. 1A (2023):311-320,
https://doi.org/10.2298/TSCI210216186V . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Bajić, Darko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6334
AB  - Zirconium dioxide ZrO2 is used as a basic material for thermal barriers and as a biomaterial for manufacturing parts for hip implants in orthopedic surgery and in dentistry for making crowns. Use of ZrO2 ceramics as an insulating material and biomaterial is due to its good chemical and dimensional stability, mechanical strength, toughness and elastic modulus. The aim of this study was to analyze the characteristics of zirconium oxide coating of stabilized cerium and yttrium oxide deposited by atmospheric plasma spraying (APS) process on the bond coating of nickel chromium cobalt yttrium oxide. Coatings were deposited on cold substrates and on substrates preheated to 180°C. Composite powder nickel chromium/aluminum/cobalt/yttrium oxide was used for the production of bond layers and for the ceramic layers zirconium oxide stabilized with cerium and yttrium oxide powder. Testing the quality of coatings was done by measuring microhardness of layers using the HV method and for bond tensile strength of the coating system tensile testing was applied. Metallographic evaluation of the share of pores in the bond and ceramic layers was performed with image analysis-processing of images from a light microscope. Powder particle morphology and EDS analysis were performed on the SEM. The obtained results confirm that the preheating temperature of the substrate has a significant impact on structural mechanical properties of the tested coatings system.
AB  - Cirkonijum dioksid ZrO2 se koristi kao osnovni materijal za izradu termalnih barijera i kao
biomaterijal za izradu delova implanata kuka u ortopedskoj hirurgiji i u stomatologiji za izradu
kruna. Korišćenje ZrO2 keramičke kao izolacionog i biomaterijala je njena dobra hemijska i
dimenzionalna stabilnost, mehanička čvrstoća, žilavost i modul elastičnosti. Cilj rada bio je da se
analiziraju karakteristike prevlake cirkonijum oksida stabilizovanog cerijum i itrijum oksidom
deponovane plazma sprej (APS) postupkom na veznoj prevlaci nikl hrom aluminijum kobalt itrijum
oksid. Prevlake su deponovane na hladnim substratima i na predgrejanim substratima na
temperaturi 180 °C. Za izradu veznih slojeva primenjen je kompozitni prah nikl
hrom/aluminijum/kobalt/itrijum oksid, a za izradu keramičkih slojeva prah cirkonijum oksida
stabilizovanog cerijum i itrijum oksidom. Ispitivanje kvaliteta prevlaka je urađena merenjem
mikrotvrdoće slojeva metodom HVi zatezne čvrstoće spoja sistema prevlaka ispitivanjem na
zatezanje. Metalografska procena udela pora u veznim i keramičkim slojevima je urađena image
analizom - obradom slika sa svetlosnog mikroskopa. Morfologije čestica prahova i EDS analiza je
urađena na SEM-u. Dobijeni rezultati potvrđuju da temperatura predgrevanja substrata ima bitan
uticaj na strukturno mehanička svojstva testiranih sistema prevlaka.
PB  - Engineers Society for Corrosion
T2  - Materials Protection
T1  - Characterization of zirconium oxidecoating stabilized with cerium and yttrium oxide deposited on the bonding coating nickel chromium aluminum cobalt yttrium oxide
T1  - Karakterizacija prevlake cirkonijum oksida stabilizovanog cerijum i itrijum oksidom deponovane na veznoj prevlaci nikl hrom aluminijum kobalt itrijum oksid
EP  - 12
IS  - 1
SP  - 5
VL  - 64
DO  - 10.5937/zasmat2301005M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Bajić, Darko",
year = "2023",
abstract = "Zirconium dioxide ZrO2 is used as a basic material for thermal barriers and as a biomaterial for manufacturing parts for hip implants in orthopedic surgery and in dentistry for making crowns. Use of ZrO2 ceramics as an insulating material and biomaterial is due to its good chemical and dimensional stability, mechanical strength, toughness and elastic modulus. The aim of this study was to analyze the characteristics of zirconium oxide coating of stabilized cerium and yttrium oxide deposited by atmospheric plasma spraying (APS) process on the bond coating of nickel chromium cobalt yttrium oxide. Coatings were deposited on cold substrates and on substrates preheated to 180°C. Composite powder nickel chromium/aluminum/cobalt/yttrium oxide was used for the production of bond layers and for the ceramic layers zirconium oxide stabilized with cerium and yttrium oxide powder. Testing the quality of coatings was done by measuring microhardness of layers using the HV method and for bond tensile strength of the coating system tensile testing was applied. Metallographic evaluation of the share of pores in the bond and ceramic layers was performed with image analysis-processing of images from a light microscope. Powder particle morphology and EDS analysis were performed on the SEM. The obtained results confirm that the preheating temperature of the substrate has a significant impact on structural mechanical properties of the tested coatings system., Cirkonijum dioksid ZrO2 se koristi kao osnovni materijal za izradu termalnih barijera i kao
biomaterijal za izradu delova implanata kuka u ortopedskoj hirurgiji i u stomatologiji za izradu
kruna. Korišćenje ZrO2 keramičke kao izolacionog i biomaterijala je njena dobra hemijska i
dimenzionalna stabilnost, mehanička čvrstoća, žilavost i modul elastičnosti. Cilj rada bio je da se
analiziraju karakteristike prevlake cirkonijum oksida stabilizovanog cerijum i itrijum oksidom
deponovane plazma sprej (APS) postupkom na veznoj prevlaci nikl hrom aluminijum kobalt itrijum
oksid. Prevlake su deponovane na hladnim substratima i na predgrejanim substratima na
temperaturi 180 °C. Za izradu veznih slojeva primenjen je kompozitni prah nikl
hrom/aluminijum/kobalt/itrijum oksid, a za izradu keramičkih slojeva prah cirkonijum oksida
stabilizovanog cerijum i itrijum oksidom. Ispitivanje kvaliteta prevlaka je urađena merenjem
mikrotvrdoće slojeva metodom HVi zatezne čvrstoće spoja sistema prevlaka ispitivanjem na
zatezanje. Metalografska procena udela pora u veznim i keramičkim slojevima je urađena image
analizom - obradom slika sa svetlosnog mikroskopa. Morfologije čestica prahova i EDS analiza je
urađena na SEM-u. Dobijeni rezultati potvrđuju da temperatura predgrevanja substrata ima bitan
uticaj na strukturno mehanička svojstva testiranih sistema prevlaka.",
publisher = "Engineers Society for Corrosion",
journal = "Materials Protection",
title = "Characterization of zirconium oxidecoating stabilized with cerium and yttrium oxide deposited on the bonding coating nickel chromium aluminum cobalt yttrium oxide, Karakterizacija prevlake cirkonijum oksida stabilizovanog cerijum i itrijum oksidom deponovane na veznoj prevlaci nikl hrom aluminijum kobalt itrijum oksid",
pages = "12-5",
number = "1",
volume = "64",
doi = "10.5937/zasmat2301005M"
}

Mrdak, M., Lačnjevac, Č.,& Bajić, D.. (2023). Characterization of zirconium oxidecoating stabilized with cerium and yttrium oxide deposited on the bonding coating nickel chromium aluminum cobalt yttrium oxide. in Materials Protection
Engineers Society for Corrosion., 64(1), 5-12.
https://doi.org/10.5937/zasmat2301005M

Mrdak M, Lačnjevac Č, Bajić D. Characterization of zirconium oxidecoating stabilized with cerium and yttrium oxide deposited on the bonding coating nickel chromium aluminum cobalt yttrium oxide. in Materials Protection. 2023;64(1):5-12.
doi:10.5937/zasmat2301005M .

Mrdak, Mihailo, Lačnjevac, Časlav, Bajić, Darko, "Characterization of zirconium oxidecoating stabilized with cerium and yttrium oxide deposited on the bonding coating nickel chromium aluminum cobalt yttrium oxide" in Materials Protection, 64, no. 1 (2023):5-12,
https://doi.org/10.5937/zasmat2301005M . .

TY  - JOUR
AU  - Veljić, Darko M.
AU  - Rakin, Marko P.
AU  - Sedmak, Aleksandar S.
AU  - Radović, Nenad A.
AU  - Međo, Bojan I.
AU  - Mrdak, Mihailo R.
AU  - Bajić, Darko R.
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5152
AB  - The influence of friction stir welding parameters on thermo-mechanical behavior of the material during welding is analyzed. An aluminum alloy is considered (Al 2024 T351), and different rotating and welding speeds are applied. The finite element model consists of the working plate (Al alloy), backing plate and welding tool. The influence of the welding conditions on material behavior is taken into account the application of the Johnson-Cook material model. The rotation speed of the tool affects the results. If increased, it contributes to an increase of friction-generated heat intensity. The other component of the generated heat, which stems from the plastic deformation of the material, is negligibly changed. When the welding speed, i.e. tool translation speed, is increased, the intensity of friction-generated heat decreases, while the heat generation due to plastic deforming is becoming more pronounced. Summed, this leads to rather small change of the total generation. The changes of the heat generation influence both the temperature field and reaction force. Also, the inadequate selection of welding parameters resulted in occurrence of the defects (pores) in the model.
PB  - VINČA Institute of Nuclear Sciences
T2  - Thermal Science
T1  - Thermo-mechanical analysis of linear welding stage in friction stir welding Influence of Welding Parameters
EP  - 2134
IS  - 3A
SP  - 2125
VL  - 26
DO  - 10.2298/TSCI210216186V
ER  - 

@article{
author = "Veljić, Darko M. and Rakin, Marko P. and Sedmak, Aleksandar S. and Radović, Nenad A. and Međo, Bojan I. and Mrdak, Mihailo R. and Bajić, Darko R.",
year = "2022",
abstract = "The influence of friction stir welding parameters on thermo-mechanical behavior of the material during welding is analyzed. An aluminum alloy is considered (Al 2024 T351), and different rotating and welding speeds are applied. The finite element model consists of the working plate (Al alloy), backing plate and welding tool. The influence of the welding conditions on material behavior is taken into account the application of the Johnson-Cook material model. The rotation speed of the tool affects the results. If increased, it contributes to an increase of friction-generated heat intensity. The other component of the generated heat, which stems from the plastic deformation of the material, is negligibly changed. When the welding speed, i.e. tool translation speed, is increased, the intensity of friction-generated heat decreases, while the heat generation due to plastic deforming is becoming more pronounced. Summed, this leads to rather small change of the total generation. The changes of the heat generation influence both the temperature field and reaction force. Also, the inadequate selection of welding parameters resulted in occurrence of the defects (pores) in the model.",
publisher = "VINČA Institute of Nuclear Sciences",
journal = "Thermal Science",
title = "Thermo-mechanical analysis of linear welding stage in friction stir welding Influence of Welding Parameters",
pages = "2134-2125",
number = "3A",
volume = "26",
doi = "10.2298/TSCI210216186V"
}

Veljić, D. M., Rakin, M. P., Sedmak, A. S., Radović, N. A., Međo, B. I., Mrdak, M. R.,& Bajić, D. R.. (2022). Thermo-mechanical analysis of linear welding stage in friction stir welding Influence of Welding Parameters. in Thermal Science
VINČA Institute of Nuclear Sciences., 26(3A), 2125-2134.
https://doi.org/10.2298/TSCI210216186V

Veljić DM, Rakin MP, Sedmak AS, Radović NA, Međo BI, Mrdak MR, Bajić DR. Thermo-mechanical analysis of linear welding stage in friction stir welding Influence of Welding Parameters. in Thermal Science. 2022;26(3A):2125-2134.
doi:10.2298/TSCI210216186V .

Veljić, Darko M., Rakin, Marko P., Sedmak, Aleksandar S., Radović, Nenad A., Međo, Bojan I., Mrdak, Mihailo R., Bajić, Darko R., "Thermo-mechanical analysis of linear welding stage in friction stir welding Influence of Welding Parameters" in Thermal Science, 26, no. 3A (2022):2125-2134,
https://doi.org/10.2298/TSCI210216186V . .

TY  - CONF
AU  - Levchenko, Oleg
AU  - Bezushko, Olga
AU  - Maidanchuk, Taras
AU  - Lukianenko, Anna
AU  - Goncharova, Olga
AU  - Bajić, Darko
AU  - Veljić, Darko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6923
AB  - The results of investigations of chemical composition and emission rates of the welding 
fume, generated during welding using electrodes for copper alloys, are presented with the aim of 
improvement of their sanitary and hygienic characteristics. It is shown that in order to create new 
grades of welding electrodes with improved hygienic characteristics, it is necessary to have the 
data of the initial sanitary and hygienic evaluation in accordance with international standards. It 
was established that the use of binder based on pure lithium liquid glass in the coating of 
electrodes for welding copper alloys, increases the rate of welding fume emission into the air, as 
well as the content of manganese and copper oxides in it. The minimum rates of harmful 
emissions were recorded during the use of sodium-potassium binder, which is recommended for 
mass production of this type of electrodes.
PB  - EDP Sciences
C3  - E3S Web of Conferences
T1  - Effect of liquid glass type on hygienic characteristics of coated electrodes for arc welding of tin bronze
SP  - 09018
VL  - 280
DO  - 10.1051/e3sconf/202128009018
ER  - 

@conference{
author = "Levchenko, Oleg and Bezushko, Olga and Maidanchuk, Taras and Lukianenko, Anna and Goncharova, Olga and Bajić, Darko and Veljić, Darko",
year = "2021",
abstract = "The results of investigations of chemical composition and emission rates of the welding 
fume, generated during welding using electrodes for copper alloys, are presented with the aim of 
improvement of their sanitary and hygienic characteristics. It is shown that in order to create new 
grades of welding electrodes with improved hygienic characteristics, it is necessary to have the 
data of the initial sanitary and hygienic evaluation in accordance with international standards. It 
was established that the use of binder based on pure lithium liquid glass in the coating of 
electrodes for welding copper alloys, increases the rate of welding fume emission into the air, as 
well as the content of manganese and copper oxides in it. The minimum rates of harmful 
emissions were recorded during the use of sodium-potassium binder, which is recommended for 
mass production of this type of electrodes.",
publisher = "EDP Sciences",
journal = "E3S Web of Conferences",
title = "Effect of liquid glass type on hygienic characteristics of coated electrodes for arc welding of tin bronze",
pages = "09018",
volume = "280",
doi = "10.1051/e3sconf/202128009018"
}

Levchenko, O., Bezushko, O., Maidanchuk, T., Lukianenko, A., Goncharova, O., Bajić, D.,& Veljić, D.. (2021). Effect of liquid glass type on hygienic characteristics of coated electrodes for arc welding of tin bronze. in E3S Web of Conferences
EDP Sciences., 280, 09018.
https://doi.org/10.1051/e3sconf/202128009018

Levchenko O, Bezushko O, Maidanchuk T, Lukianenko A, Goncharova O, Bajić D, Veljić D. Effect of liquid glass type on hygienic characteristics of coated electrodes for arc welding of tin bronze. in E3S Web of Conferences. 2021;280:09018.
doi:10.1051/e3sconf/202128009018 .

Levchenko, Oleg, Bezushko, Olga, Maidanchuk, Taras, Lukianenko, Anna, Goncharova, Olga, Bajić, Darko, Veljić, Darko, "Effect of liquid glass type on hygienic characteristics of coated electrodes for arc welding of tin bronze" in E3S Web of Conferences, 280 (2021):09018,
https://doi.org/10.1051/e3sconf/202128009018 . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Janaćković, Đorđe
AU  - Veljić, Darko
AU  - Bajić, Darko
PY  - 2021
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/6035
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5036
AB  - The aim of this study was to deposit multi-functional ZrO28%Y2O3 coating layers using the plasma spray technology and then to characterise such layers. In combination with other biomedical ceramics, this coating is intended for the application in implant surface modification. The examination was focused on the mechanical properties and microstructure layers. Using the atmospheric plasma spraying, duplex ZrO28%Y2O3/Ni22Cr10Al1Y coating system was deposited on the X15Cr13 stainless steel, with two different thicknesses of the bond and ceramic coatings. The microstructure was analysed using an optical microscope, including the assessment of the content of micropores. The morphology of powder particles and ceramic coating surfaces were examined on a scanning electron microscope (SEM). The quality of the ZrO28%Y2O3 layers makes them suitable for the application and combination with other materials to create a system of biomedical or multifunctional coatings.
AB  - Cilj ovog rada bio je da se deponuju višenamenski slojevi prevlake ZrO28%Y2O3 primenom plazma
sprej tehnologije, a zatim da se karakterišu takvi slojevi. U kombinaciji sa drugom biomedicinskom
keramikom, ova prevlaka je namenjena primeni u modifikaciji površine implantata. spitivanje je
bilo usredsređeno na mehanička svojstva i mikrostrukturu slojeva. orišćenjem atmosferskog
plazma spreja, dupleks sistem prevlaka ZrO28%Y2O3 / Ni22Cr10Al1 nanet je na nerđajući čelik
X15Cr13, sa dve različite debljine vezne i keramičke prevlake. ikrostruktura je analizirana
pomoću optičkog mikroskopa, uključujući procenu sadr aja mikro pora. orfologija čestica praha i
površina keramičkih prevlaka ispitivane su na skening elektronskom mikroskopu (SE ). valitet
slojeva ZrO28%Y2O3 čini ih pogodnim za nanošenje i kombinaciju sa drugim materijalima kako bi
se stvorio sistem biomedicinskih ili multifunkcionalnih prevlaka.
PB  - Inženjersko društvo za koroziju
T2  - Zaštita materijala
T1  - Characterisation of biocompatible layers of ZrO28%Y2O used in combination with other ceramics to modify the surface of implants
T1  - Karakterizacija biokompatibilnih slojeva ZrO28%Y2O3 koji se koriste u kombinaciji sa drugom keramikom za modifikaciju površine implantata
EP  - 268
IS  - 4
SP  - 262
VL  - 62
DO  - 10.5937/zasmat2104262M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Janaćković, Đorđe and Veljić, Darko and Bajić, Darko",
year = "2021",
abstract = "The aim of this study was to deposit multi-functional ZrO28%Y2O3 coating layers using the plasma spray technology and then to characterise such layers. In combination with other biomedical ceramics, this coating is intended for the application in implant surface modification. The examination was focused on the mechanical properties and microstructure layers. Using the atmospheric plasma spraying, duplex ZrO28%Y2O3/Ni22Cr10Al1Y coating system was deposited on the X15Cr13 stainless steel, with two different thicknesses of the bond and ceramic coatings. The microstructure was analysed using an optical microscope, including the assessment of the content of micropores. The morphology of powder particles and ceramic coating surfaces were examined on a scanning electron microscope (SEM). The quality of the ZrO28%Y2O3 layers makes them suitable for the application and combination with other materials to create a system of biomedical or multifunctional coatings., Cilj ovog rada bio je da se deponuju višenamenski slojevi prevlake ZrO28%Y2O3 primenom plazma
sprej tehnologije, a zatim da se karakterišu takvi slojevi. U kombinaciji sa drugom biomedicinskom
keramikom, ova prevlaka je namenjena primeni u modifikaciji površine implantata. spitivanje je
bilo usredsređeno na mehanička svojstva i mikrostrukturu slojeva. orišćenjem atmosferskog
plazma spreja, dupleks sistem prevlaka ZrO28%Y2O3 / Ni22Cr10Al1 nanet je na nerđajući čelik
X15Cr13, sa dve različite debljine vezne i keramičke prevlake. ikrostruktura je analizirana
pomoću optičkog mikroskopa, uključujući procenu sadr aja mikro pora. orfologija čestica praha i
površina keramičkih prevlaka ispitivane su na skening elektronskom mikroskopu (SE ). valitet
slojeva ZrO28%Y2O3 čini ih pogodnim za nanošenje i kombinaciju sa drugim materijalima kako bi
se stvorio sistem biomedicinskih ili multifunkcionalnih prevlaka.",
publisher = "Inženjersko društvo za koroziju",
journal = "Zaštita materijala",
title = "Characterisation of biocompatible layers of ZrO28%Y2O used in combination with other ceramics to modify the surface of implants, Karakterizacija biokompatibilnih slojeva ZrO28%Y2O3 koji se koriste u kombinaciji sa drugom keramikom za modifikaciju površine implantata",
pages = "268-262",
number = "4",
volume = "62",
doi = "10.5937/zasmat2104262M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Janaćković, Đ., Veljić, D.,& Bajić, D.. (2021). Characterisation of biocompatible layers of ZrO28%Y2O used in combination with other ceramics to modify the surface of implants. in Zaštita materijala
Inženjersko društvo za koroziju., 62(4), 262-268.
https://doi.org/10.5937/zasmat2104262M

Mrdak M, Lačnjevac Č, Rakin M, Janaćković Đ, Veljić D, Bajić D. Characterisation of biocompatible layers of ZrO28%Y2O used in combination with other ceramics to modify the surface of implants. in Zaštita materijala. 2021;62(4):262-268.
doi:10.5937/zasmat2104262M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Janaćković, Đorđe, Veljić, Darko, Bajić, Darko, "Characterisation of biocompatible layers of ZrO28%Y2O used in combination with other ceramics to modify the surface of implants" in Zaštita materijala, 62, no. 4 (2021):262-268,
https://doi.org/10.5937/zasmat2104262M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Janaćković, Đorđe
AU  - Veljić, Darko
AU  - Bajić, Darko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5119
AB  - In this paper, analyzed are the effects of the plasma spray distance on the microstructure and mechanical properties of the NiCrAlCoY2O3 coating layers deposited at atmospheric pressure. The microstructure and mechanical properties of the coating layers are under the influence of the interaction of plasma particles (ions and electrons) with powder particles, providing the transfer of velocity and temperature of the plasma particles onto the powder particles. The effect of the interaction is directly dependent on the time the powder particles were present in the plasma which is defined by distance of the plasma gun from the substrate, depending on the granulation of the powder, the melting point and specific gravity. In order to obtain homogeneous and denser coating layers with high adhesion, in the experiment three distances from the substrate were used: 95 mm, 105 mm and 115 mm. The layers were deposited on thin sheets of AlMg1 aluminum thickness of 0.6 mm. Evaluation of mechanical properties of the layers was carried out by examining microhardness using the HV0.1 method and the bond strength by tensile testing. The morphology of the powder particles was examined on the SEM, while the microstructure of the layers was evaluated under a light microscope in accordance with the Pratt Whitney standard. The results of the experiment showed that the distance from the substrate substantially influenced the structure and mechanical properties of the coating layers. The best deposited layers were examined in the system with the ZrO224%MgO ceramic coating, which have proved to be reliable protectionfrom high temperature and abrasive rocket jet fuel.
PB  - Engineers Society for Corrosion
T2  - Materials Protection
T1  - [Characterization of deposited plasma spray nicralcoy2o3 coating layers on almg1 alloy substrates] [Karakterizacija deponovanih slojeva plazma sprej prevlake nicralcoy2o3 na podlogama od legure almg1]
EP  - 40
IS  - 1
SP  - 34
VL  - 2021
DO  - 10.5937/zasmat2101034M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Janaćković, Đorđe and Veljić, Darko and Bajić, Darko",
year = "2021",
abstract = "In this paper, analyzed are the effects of the plasma spray distance on the microstructure and mechanical properties of the NiCrAlCoY2O3 coating layers deposited at atmospheric pressure. The microstructure and mechanical properties of the coating layers are under the influence of the interaction of plasma particles (ions and electrons) with powder particles, providing the transfer of velocity and temperature of the plasma particles onto the powder particles. The effect of the interaction is directly dependent on the time the powder particles were present in the plasma which is defined by distance of the plasma gun from the substrate, depending on the granulation of the powder, the melting point and specific gravity. In order to obtain homogeneous and denser coating layers with high adhesion, in the experiment three distances from the substrate were used: 95 mm, 105 mm and 115 mm. The layers were deposited on thin sheets of AlMg1 aluminum thickness of 0.6 mm. Evaluation of mechanical properties of the layers was carried out by examining microhardness using the HV0.1 method and the bond strength by tensile testing. The morphology of the powder particles was examined on the SEM, while the microstructure of the layers was evaluated under a light microscope in accordance with the Pratt Whitney standard. The results of the experiment showed that the distance from the substrate substantially influenced the structure and mechanical properties of the coating layers. The best deposited layers were examined in the system with the ZrO224%MgO ceramic coating, which have proved to be reliable protectionfrom high temperature and abrasive rocket jet fuel.",
publisher = "Engineers Society for Corrosion",
journal = "Materials Protection",
title = "[Characterization of deposited plasma spray nicralcoy2o3 coating layers on almg1 alloy substrates] [Karakterizacija deponovanih slojeva plazma sprej prevlake nicralcoy2o3 na podlogama od legure almg1]",
pages = "40-34",
number = "1",
volume = "2021",
doi = "10.5937/zasmat2101034M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Janaćković, Đ., Veljić, D.,& Bajić, D.. (2021). [Characterization of deposited plasma spray nicralcoy2o3 coating layers on almg1 alloy substrates] [Karakterizacija deponovanih slojeva plazma sprej prevlake nicralcoy2o3 na podlogama od legure almg1]. in Materials Protection
Engineers Society for Corrosion., 2021(1), 34-40.
https://doi.org/10.5937/zasmat2101034M

Mrdak M, Lačnjevac Č, Rakin M, Janaćković Đ, Veljić D, Bajić D. [Characterization of deposited plasma spray nicralcoy2o3 coating layers on almg1 alloy substrates] [Karakterizacija deponovanih slojeva plazma sprej prevlake nicralcoy2o3 na podlogama od legure almg1]. in Materials Protection. 2021;2021(1):34-40.
doi:10.5937/zasmat2101034M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Janaćković, Đorđe, Veljić, Darko, Bajić, Darko, "[Characterization of deposited plasma spray nicralcoy2o3 coating layers on almg1 alloy substrates] [Karakterizacija deponovanih slojeva plazma sprej prevlake nicralcoy2o3 na podlogama od legure almg1]" in Materials Protection, 2021, no. 1 (2021):34-40,
https://doi.org/10.5937/zasmat2101034M . .

TY  - JOUR
AU  - Bajić, Darko
AU  - Mrdak, Mihailo
AU  - Bajić, Nikola
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Radosavljević, Zoran
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4534
AB  - In this paper, we will present our investigation of the quality of J55 microalloyed steel welds that were formed by a basic flux-cored wire electrodes that were of appropriate quality and alloyed with Ni and Mo. Based on the comparison and analysis of the obtained results related to the testing of the chemical composition, mechanical properties, toughness at test temperatures, and the microstructure of welding joints formed by a classic and specially coated rutile flux-cored electrode, we assessed the justification to switch from solid wire electrodes to flux-cored alloyed wire electrodes of appropriate quality. The research aim for the application of flux-cored wire electrodes instead of solid wire electrodes is based on the advantages pertaining to a flux-cored wire: molten metal from electrode wire is transferred in the form of fine droplets, easy welding and maximum productivity within all spatial positions related to welding, improved properties of welding joints, and increased productivity when compared to a classic solid wire. Our research encompasses the development of the experimental production at the Research and Development Center IHIS Belgrade (Development Institute for Chemical Power Sources), Serbia, of the new type of a coated electrode with improved welding properties when compared to a classic electrode intended for microalloyed steel welding.
PB  - MDPI, Basel
T2  - Materials
T1  - Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding
IS  - 9
VL  - 13
DO  - 10.3390/ma13092152
ER  - 

@article{
author = "Bajić, Darko and Mrdak, Mihailo and Bajić, Nikola and Veljić, Darko and Rakin, Marko and Radosavljević, Zoran",
year = "2020",
abstract = "In this paper, we will present our investigation of the quality of J55 microalloyed steel welds that were formed by a basic flux-cored wire electrodes that were of appropriate quality and alloyed with Ni and Mo. Based on the comparison and analysis of the obtained results related to the testing of the chemical composition, mechanical properties, toughness at test temperatures, and the microstructure of welding joints formed by a classic and specially coated rutile flux-cored electrode, we assessed the justification to switch from solid wire electrodes to flux-cored alloyed wire electrodes of appropriate quality. The research aim for the application of flux-cored wire electrodes instead of solid wire electrodes is based on the advantages pertaining to a flux-cored wire: molten metal from electrode wire is transferred in the form of fine droplets, easy welding and maximum productivity within all spatial positions related to welding, improved properties of welding joints, and increased productivity when compared to a classic solid wire. Our research encompasses the development of the experimental production at the Research and Development Center IHIS Belgrade (Development Institute for Chemical Power Sources), Serbia, of the new type of a coated electrode with improved welding properties when compared to a classic electrode intended for microalloyed steel welding.",
publisher = "MDPI, Basel",
journal = "Materials",
title = "Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding",
number = "9",
volume = "13",
doi = "10.3390/ma13092152"
}

Bajić, D., Mrdak, M., Bajić, N., Veljić, D., Rakin, M.,& Radosavljević, Z.. (2020). Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding. in Materials
MDPI, Basel., 13(9).
https://doi.org/10.3390/ma13092152

Bajić D, Mrdak M, Bajić N, Veljić D, Rakin M, Radosavljević Z. Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding. in Materials. 2020;13(9).
doi:10.3390/ma13092152 .

Bajić, Darko, Mrdak, Mihailo, Bajić, Nikola, Veljić, Darko, Rakin, Marko, Radosavljević, Zoran, "Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding" in Materials, 13, no. 9 (2020),
https://doi.org/10.3390/ma13092152 . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Janaćković, Đorđe
AU  - Veljić, Darko
AU  - Bajić, Darko
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4552
AB  - The topography of the surface of the deposited VPS-Ti coatings on substrate surfaces of implants relating to the roughness and porous structure plays a decisive role in the process of on growth of the implants to the bones i.e.osseointegration. Direct bone on growth has been successfully achieved by using micro rough coating surfaces, such as the use of vacuum plasma spraying VPS-Ti coatings. The aim of this study was to make a comprehensive review of the characterization of porous VPS-Ti coatings deposited on substrates of titanium alloy that will find application in orthopedics.One of the preferred features of the VPS process is the ability to achieve optimum macro and micro structure of the surface of implants by optimizing the spray parameters of the powder deposition and by the range of the powder granulation. In order to achieve an optimum surface roughness, open porosity and structure of VPS-Ti coatings conducted was the optimization of deposition of powder with a change in plasma current and powder carrier gas flow rate of (700 A, 35 l/min and 800A, 20 l/min). Lower intensity plasma current with a greater flow of powder heats and melts the powder particles less forming micro pores of a larger size and a higher proportion of open pores and vice versa higher plasma currents and reduced flow provide better melted particles forming a smaller share of micro pores and open porosity in the deposited layers. Image analysis showed that by optimization of parameters in the coatings open porosity can be formed ranging from 45% to 57%. By examining the properties of the deposited layers it was determined that the most optimal roughness and share of open pores for osseointegration have the Ti layers which have been deposited with the lowest amperage and highest flow of powder carrier gas.
AB  - Topografija površine deponovanih VPS-Ti prevlaka na podlogama implanata koja se odnosi na hrapavost i poroznu strukturu imaju odlučujuću ulogu u procesu srastanja implanata sa kostima odnosno osteointegraciju Direktno urastanje kostiju uspešno se posti e korišćenjem mikro grubih površina prevlaka, kao što je primena vakuum plazma sprej VPS - Ti prevlake. Cilj ovog rada je bio da se napravi sveobuhvatan pregled karakterizacija VPS-Ti poroznih prevlaka deponovanih na podlogama od legure titana koje će naći aplikaciju u ortopediji. Jedna od povoljnih osobina VPS procesa je mogućnost postizanja optimalne makro i mikro strukture površine implanata optimizacijom sprej parametara depozicije praha i rasponom granulacije praha. U cilju postizanja optimalne hrapavosti, otvorene poroznosti i strukture VPS-Ti prevlaka sprovedena je optimizacija depozicije praha sa promenom plazma struje i protokom nosećeg gasa praha (700 A, 35 l/min i 800A, 20 l/min) Ni a jačina plazma struje uz veći protok praha slabije progreva i topi čestice praha obrazujući mikro pore veće veličine i veći udeo otvorenih pora i obrnuto veća plazma struja i manji protok omogućuju bolje topljenje čestica uz formiranje manjeg udela mikro pora i otvorene poroznosti u deponovanim slojevima. Analizom slika ustanovljeno je da se sa optimizacijom parametara u prevlakama mo e formirati otvorena poroznost sa rasponom od 45% do 57% Ispitivanjem karakteristika deponovanih slojeva ustanovljeno je da najoptimalniju hrapavost i udeo otvorenih pora za osteointegraciju imaju slojevi Ti deponovani sa najni om ampera om i najvećim protokom nosećeg gasa praha.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - The mechanical and microstructural properties of VPS-Ti porous coating deposited on titanium alloy substrates for osseointegration
T1  - Mehanička i mikrostrukturna svojstva VPS-Ti porozne prevlake deponovane na podlogama od legure titana za osteointegraciju
EP  - 59
IS  - 1
SP  - 52
VL  - 61
DO  - 10.5937/zasmat2001052M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Janaćković, Đorđe and Veljić, Darko and Bajić, Darko",
year = "2020",
abstract = "The topography of the surface of the deposited VPS-Ti coatings on substrate surfaces of implants relating to the roughness and porous structure plays a decisive role in the process of on growth of the implants to the bones i.e.osseointegration. Direct bone on growth has been successfully achieved by using micro rough coating surfaces, such as the use of vacuum plasma spraying VPS-Ti coatings. The aim of this study was to make a comprehensive review of the characterization of porous VPS-Ti coatings deposited on substrates of titanium alloy that will find application in orthopedics.One of the preferred features of the VPS process is the ability to achieve optimum macro and micro structure of the surface of implants by optimizing the spray parameters of the powder deposition and by the range of the powder granulation. In order to achieve an optimum surface roughness, open porosity and structure of VPS-Ti coatings conducted was the optimization of deposition of powder with a change in plasma current and powder carrier gas flow rate of (700 A, 35 l/min and 800A, 20 l/min). Lower intensity plasma current with a greater flow of powder heats and melts the powder particles less forming micro pores of a larger size and a higher proportion of open pores and vice versa higher plasma currents and reduced flow provide better melted particles forming a smaller share of micro pores and open porosity in the deposited layers. Image analysis showed that by optimization of parameters in the coatings open porosity can be formed ranging from 45% to 57%. By examining the properties of the deposited layers it was determined that the most optimal roughness and share of open pores for osseointegration have the Ti layers which have been deposited with the lowest amperage and highest flow of powder carrier gas., Topografija površine deponovanih VPS-Ti prevlaka na podlogama implanata koja se odnosi na hrapavost i poroznu strukturu imaju odlučujuću ulogu u procesu srastanja implanata sa kostima odnosno osteointegraciju Direktno urastanje kostiju uspešno se posti e korišćenjem mikro grubih površina prevlaka, kao što je primena vakuum plazma sprej VPS - Ti prevlake. Cilj ovog rada je bio da se napravi sveobuhvatan pregled karakterizacija VPS-Ti poroznih prevlaka deponovanih na podlogama od legure titana koje će naći aplikaciju u ortopediji. Jedna od povoljnih osobina VPS procesa je mogućnost postizanja optimalne makro i mikro strukture površine implanata optimizacijom sprej parametara depozicije praha i rasponom granulacije praha. U cilju postizanja optimalne hrapavosti, otvorene poroznosti i strukture VPS-Ti prevlaka sprovedena je optimizacija depozicije praha sa promenom plazma struje i protokom nosećeg gasa praha (700 A, 35 l/min i 800A, 20 l/min) Ni a jačina plazma struje uz veći protok praha slabije progreva i topi čestice praha obrazujući mikro pore veće veličine i veći udeo otvorenih pora i obrnuto veća plazma struja i manji protok omogućuju bolje topljenje čestica uz formiranje manjeg udela mikro pora i otvorene poroznosti u deponovanim slojevima. Analizom slika ustanovljeno je da se sa optimizacijom parametara u prevlakama mo e formirati otvorena poroznost sa rasponom od 45% do 57% Ispitivanjem karakteristika deponovanih slojeva ustanovljeno je da najoptimalniju hrapavost i udeo otvorenih pora za osteointegraciju imaju slojevi Ti deponovani sa najni om ampera om i najvećim protokom nosećeg gasa praha.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "The mechanical and microstructural properties of VPS-Ti porous coating deposited on titanium alloy substrates for osseointegration, Mehanička i mikrostrukturna svojstva VPS-Ti porozne prevlake deponovane na podlogama od legure titana za osteointegraciju",
pages = "59-52",
number = "1",
volume = "61",
doi = "10.5937/zasmat2001052M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Janaćković, Đ., Veljić, D.,& Bajić, D.. (2020). The mechanical and microstructural properties of VPS-Ti porous coating deposited on titanium alloy substrates for osseointegration. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 61(1), 52-59.
https://doi.org/10.5937/zasmat2001052M

Mrdak M, Lačnjevac Č, Rakin M, Janaćković Đ, Veljić D, Bajić D. The mechanical and microstructural properties of VPS-Ti porous coating deposited on titanium alloy substrates for osseointegration. in Zaštita materijala. 2020;61(1):52-59.
doi:10.5937/zasmat2001052M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Janaćković, Đorđe, Veljić, Darko, Bajić, Darko, "The mechanical and microstructural properties of VPS-Ti porous coating deposited on titanium alloy substrates for osseointegration" in Zaštita materijala, 61, no. 1 (2020):52-59,
https://doi.org/10.5937/zasmat2001052M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Rakin, Marko
AU  - Janaćković, Đorđe
AU  - Veljić, Darko
AU  - Bajić, Darko
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4555
AB  - In this paper analyzed were the mechanical properties and microstructure of the Ni30Al coating layers deposited using atmospheric plasma spray (APS). For deposition of the coating applied was a composite Ni30wt.% Al powder, manufactured by mechanical alloying of granulation below - 180 µm. The coatings mechanical properties were analyzed by microhardness measuring with the HV0.3 method and the bond strength by tension method. For the analysis of the microstructure of the coating layers applied was the method of light and scanning electron microscopy (SEM). Microhardness tests showed that the coating has a wide range of measured values which indicate a heterogeneous multiphase lamellar microstructure of the coating, which was confirmed by metallographic examination of the layers. The multi-phase lamellar microstructure consisted of the initial solid a-Al, y-Ni solutions, formed solid b-NiAl and NiAl martensite solutions, intermetallic compounds y-Ni3Al and Ni2Al3 and the oxide y-Al2O3 phase formed by oxidation of molten Al particles. Based on these tests given was an evaluation of the quality of the coating. The results of the experiment showed that the technological process of production of composite powders significantly affects the mechanical properties and structure of the coating layers.
AB  - U ovom radu analizirane su mehaničke osobine i mikrostruktura slojeva prevlake Ni30Al deponovane atmosferskim plazma sprejom (APS). Za depoziciju prevlake primenjen je kompozitni prah Ni30tež.%Al proizveden mehaničkim legiranjem granulacije ispod - 180 µm. Mehaničke karakteristike prevlake analizirane su merenjem mikrotvrdoće metodom HV0.3 i čvrstoće spoja metodom na zatezanje. Za analizu mikrostrukture slojeva prevlake primenjena je metoda svetlosne i skening elektronske mikroskopije (SEM). Ispitivanja mikrotvrdoće su pokazala da prevlaka ima širok opseg izmerenih vrednosti koje ukazuju na višefaznu heterogenu lamelarnu mikrostrukturu prevlake, koja je potvrđena metalografskaim ispitivanjem slojeva. Višefazna lamelarna mikrostruktura se sastojala od polaznih čvrstih rastvora a-Al, y-Ni, formiranih čvrstih rastvora b-NiAl i NiAl martenzita, intermetalnih jedinjenja y-Ni3Al i Ni2Al3 i oksidne faze y-Al2O3 nastale oksidacijim istopljenih čestica Al. Na osnovu sprovedenih ispitivanja dala se ocena kvaliteta prevlake. Rezultati eksperimenta su pokazali da tehnološki postupak proizvodnje kompozitnih prahova bitno utiče na mehaničke karakteristike i strukturu slojeva prevlake.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Characterization of NiAl layers deposited by atmospheric plasma spray (APS)
T1  - Karakterizacija NiAl slojeva deponovanih atmosferskim plazma sprejom (APS)
EP  - 115
IS  - 2
SP  - 110
VL  - 61
DO  - 10.5937/zasmat2002110M
ER  - 

@article{
author = "Mrdak, Mihailo and Rakin, Marko and Janaćković, Đorđe and Veljić, Darko and Bajić, Darko",
year = "2020",
abstract = "In this paper analyzed were the mechanical properties and microstructure of the Ni30Al coating layers deposited using atmospheric plasma spray (APS). For deposition of the coating applied was a composite Ni30wt.% Al powder, manufactured by mechanical alloying of granulation below - 180 µm. The coatings mechanical properties were analyzed by microhardness measuring with the HV0.3 method and the bond strength by tension method. For the analysis of the microstructure of the coating layers applied was the method of light and scanning electron microscopy (SEM). Microhardness tests showed that the coating has a wide range of measured values which indicate a heterogeneous multiphase lamellar microstructure of the coating, which was confirmed by metallographic examination of the layers. The multi-phase lamellar microstructure consisted of the initial solid a-Al, y-Ni solutions, formed solid b-NiAl and NiAl martensite solutions, intermetallic compounds y-Ni3Al and Ni2Al3 and the oxide y-Al2O3 phase formed by oxidation of molten Al particles. Based on these tests given was an evaluation of the quality of the coating. The results of the experiment showed that the technological process of production of composite powders significantly affects the mechanical properties and structure of the coating layers., U ovom radu analizirane su mehaničke osobine i mikrostruktura slojeva prevlake Ni30Al deponovane atmosferskim plazma sprejom (APS). Za depoziciju prevlake primenjen je kompozitni prah Ni30tež.%Al proizveden mehaničkim legiranjem granulacije ispod - 180 µm. Mehaničke karakteristike prevlake analizirane su merenjem mikrotvrdoće metodom HV0.3 i čvrstoće spoja metodom na zatezanje. Za analizu mikrostrukture slojeva prevlake primenjena je metoda svetlosne i skening elektronske mikroskopije (SEM). Ispitivanja mikrotvrdoće su pokazala da prevlaka ima širok opseg izmerenih vrednosti koje ukazuju na višefaznu heterogenu lamelarnu mikrostrukturu prevlake, koja je potvrđena metalografskaim ispitivanjem slojeva. Višefazna lamelarna mikrostruktura se sastojala od polaznih čvrstih rastvora a-Al, y-Ni, formiranih čvrstih rastvora b-NiAl i NiAl martenzita, intermetalnih jedinjenja y-Ni3Al i Ni2Al3 i oksidne faze y-Al2O3 nastale oksidacijim istopljenih čestica Al. Na osnovu sprovedenih ispitivanja dala se ocena kvaliteta prevlake. Rezultati eksperimenta su pokazali da tehnološki postupak proizvodnje kompozitnih prahova bitno utiče na mehaničke karakteristike i strukturu slojeva prevlake.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Characterization of NiAl layers deposited by atmospheric plasma spray (APS), Karakterizacija NiAl slojeva deponovanih atmosferskim plazma sprejom (APS)",
pages = "115-110",
number = "2",
volume = "61",
doi = "10.5937/zasmat2002110M"
}

Mrdak, M., Rakin, M., Janaćković, Đ., Veljić, D.,& Bajić, D.. (2020). Characterization of NiAl layers deposited by atmospheric plasma spray (APS). in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 61(2), 110-115.
https://doi.org/10.5937/zasmat2002110M

Mrdak M, Rakin M, Janaćković Đ, Veljić D, Bajić D. Characterization of NiAl layers deposited by atmospheric plasma spray (APS). in Zaštita materijala. 2020;61(2):110-115.
doi:10.5937/zasmat2002110M .

Mrdak, Mihailo, Rakin, Marko, Janaćković, Đorđe, Veljić, Darko, Bajić, Darko, "Characterization of NiAl layers deposited by atmospheric plasma spray (APS)" in Zaštita materijala, 61, no. 2 (2020):110-115,
https://doi.org/10.5937/zasmat2002110M . .

TY  - JOUR
AU  - Veljić, Darko
AU  - Sedmak, Aleksandar
AU  - Rakin, Marko
AU  - Bajić, Nikola
AU  - Međo, Bojan
AU  - Bajić, Darko
AU  - Grabulov, Vencislav
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2678
AB  - This paper presents experimental and numerical analysis of the change of temperature and force in the vertical direction during the friction stir welding of high-strength aluminium alloy 2024 T3. This procedure confirmed the correctness of the numerical model, which is subsequently used for analysis of the temperature field in the welding zone, where it is different to determine the temperature experimentally. 3D finite element model is developed using the software package Abaqus; arbitrary Lagrangian-Eulerian formulation is applied. Johnson-Cook material law and Coulomb's Law of friction are used for modelling the material behaviour. Temperature fields are symmetrical with respect to the welding line. The temperature values below the tool shoulder, i.e. in the welding zone, which are reached during the plunge stage, are approximately constant during the entire welding process and lie within the interval 430-502 degrees C. The temperature of the material in the vicinity of the tool is about 500 degrees C, while the values on the top surface of the welding plates (outside the welding zone, but close to the tool shoulder) are about 400 degrees C. The temperature difference between the top and bottom surface of the plates is small, 10-15 degrees C.
PB  - Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd
T2  - Thermal Science
T1  - Experimental and numerical thermo - mechanical analysis of friction stir welding of high - strength alluminium alloy
EP  - S38
SP  - S29
VL  - 18
DO  - 10.2298/TSCI130512171V
ER  - 

@article{
author = "Veljić, Darko and Sedmak, Aleksandar and Rakin, Marko and Bajić, Nikola and Međo, Bojan and Bajić, Darko and Grabulov, Vencislav",
year = "2014",
abstract = "This paper presents experimental and numerical analysis of the change of temperature and force in the vertical direction during the friction stir welding of high-strength aluminium alloy 2024 T3. This procedure confirmed the correctness of the numerical model, which is subsequently used for analysis of the temperature field in the welding zone, where it is different to determine the temperature experimentally. 3D finite element model is developed using the software package Abaqus; arbitrary Lagrangian-Eulerian formulation is applied. Johnson-Cook material law and Coulomb's Law of friction are used for modelling the material behaviour. Temperature fields are symmetrical with respect to the welding line. The temperature values below the tool shoulder, i.e. in the welding zone, which are reached during the plunge stage, are approximately constant during the entire welding process and lie within the interval 430-502 degrees C. The temperature of the material in the vicinity of the tool is about 500 degrees C, while the values on the top surface of the welding plates (outside the welding zone, but close to the tool shoulder) are about 400 degrees C. The temperature difference between the top and bottom surface of the plates is small, 10-15 degrees C.",
publisher = "Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd",
journal = "Thermal Science",
title = "Experimental and numerical thermo - mechanical analysis of friction stir welding of high - strength alluminium alloy",
pages = "S38-S29",
volume = "18",
doi = "10.2298/TSCI130512171V"
}

Veljić, D., Sedmak, A., Rakin, M., Bajić, N., Međo, B., Bajić, D.,& Grabulov, V.. (2014). Experimental and numerical thermo - mechanical analysis of friction stir welding of high - strength alluminium alloy. in Thermal Science
Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd., 18, S29-S38.
https://doi.org/10.2298/TSCI130512171V

Veljić D, Sedmak A, Rakin M, Bajić N, Međo B, Bajić D, Grabulov V. Experimental and numerical thermo - mechanical analysis of friction stir welding of high - strength alluminium alloy. in Thermal Science. 2014;18:S29-S38.
doi:10.2298/TSCI130512171V .

Veljić, Darko, Sedmak, Aleksandar, Rakin, Marko, Bajić, Nikola, Međo, Bojan, Bajić, Darko, Grabulov, Vencislav, "Experimental and numerical thermo - mechanical analysis of friction stir welding of high - strength alluminium alloy" in Thermal Science, 18 (2014):S29-S38,
https://doi.org/10.2298/TSCI130512171V . .

TY  - JOUR
AU  - Bajić, N.
AU  - Bajić, Darko
AU  - Veljić, Darko
AU  - Rakin, Marko
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2527
AB  - The objective of this paper is the analysis and evaluation of the quality of the new flux-cored wire designed for the MAG welding process that was developed and produced using special laboratory equipment. Experimental welding was performed with the new activated flux-cored wire and classic solid wire with changing of welding parameters and shielding gas composition (100 % CO2 and gas mixtures of Ar + CO2 + O-2).
PB  - Croatian Metallurgical Soc, Zagreb
T2  - Metalurgija
T1  - Advantage of use of activated flux-cored wire instead of solid wire with the mag welding process from the mechanical properties aspect
EP  - 456
IS  - 4
SP  - 453
VL  - 52
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2527
ER  - 

@article{
author = "Bajić, N. and Bajić, Darko and Veljić, Darko and Rakin, Marko",
year = "2013",
abstract = "The objective of this paper is the analysis and evaluation of the quality of the new flux-cored wire designed for the MAG welding process that was developed and produced using special laboratory equipment. Experimental welding was performed with the new activated flux-cored wire and classic solid wire with changing of welding parameters and shielding gas composition (100 % CO2 and gas mixtures of Ar + CO2 + O-2).",
publisher = "Croatian Metallurgical Soc, Zagreb",
journal = "Metalurgija",
title = "Advantage of use of activated flux-cored wire instead of solid wire with the mag welding process from the mechanical properties aspect",
pages = "456-453",
number = "4",
volume = "52",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2527"
}

Bajić, N., Bajić, D., Veljić, D.,& Rakin, M.. (2013). Advantage of use of activated flux-cored wire instead of solid wire with the mag welding process from the mechanical properties aspect. in Metalurgija
Croatian Metallurgical Soc, Zagreb., 52(4), 453-456.
https://hdl.handle.net/21.15107/rcub_technorep_2527

Bajić N, Bajić D, Veljić D, Rakin M. Advantage of use of activated flux-cored wire instead of solid wire with the mag welding process from the mechanical properties aspect. in Metalurgija. 2013;52(4):453-456.
https://hdl.handle.net/21.15107/rcub_technorep_2527 .

Bajić, N., Bajić, Darko, Veljić, Darko, Rakin, Marko, "Advantage of use of activated flux-cored wire instead of solid wire with the mag welding process from the mechanical properties aspect" in Metalurgija, 52, no. 4 (2013):453-456,
https://hdl.handle.net/21.15107/rcub_technorep_2527 .

TY  - JOUR
AU  - Veljić, Darko
AU  - Perović, Milenko
AU  - Sedmak, Aleksandar
AU  - Rakin, Marko
AU  - Trifunović, Miroslav V.
AU  - Bajić, Nikola
AU  - Bajić, Darko
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2029
AB  - A coupled thermo-mechanical model was developed to study the temperature fields, the plunge force and the plastic deformations of Al alloy 2024-T351 under different rotating speed: 350, 400, and 450 rpm, during the friction stir welding process. 3-D FE model has been developed in ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson-Cook material law, and the Coulomb’s Law of friction. Numerical results indicate that the maximum temperature in the friction stir welding process is lower than the melting point of the welding material. The temperature filed is approximately symmetrical along the welding line. A lower plastic strain region can be found near the welding tool in the trailing side on the bottom surface. With increasing rotation speed, the low plastic strain region is reduced. When the rotational speed is increased, the plunge force can be reduced. Regions with high equivalent plastic strains are observed which correspond to the nugget and the flow arm.
PB  - Vinca Institute of Nuclear Sciences
T2  - Thermal Science
T1  - A coupled thermo-mechanical model of friction stir welding
EP  - 534
IS  - 2
SP  - 527
VL  - 16
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2029
ER  - 

@article{
author = "Veljić, Darko and Perović, Milenko and Sedmak, Aleksandar and Rakin, Marko and Trifunović, Miroslav V. and Bajić, Nikola and Bajić, Darko",
year = "2012",
abstract = "A coupled thermo-mechanical model was developed to study the temperature fields, the plunge force and the plastic deformations of Al alloy 2024-T351 under different rotating speed: 350, 400, and 450 rpm, during the friction stir welding process. 3-D FE model has been developed in ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson-Cook material law, and the Coulomb’s Law of friction. Numerical results indicate that the maximum temperature in the friction stir welding process is lower than the melting point of the welding material. The temperature filed is approximately symmetrical along the welding line. A lower plastic strain region can be found near the welding tool in the trailing side on the bottom surface. With increasing rotation speed, the low plastic strain region is reduced. When the rotational speed is increased, the plunge force can be reduced. Regions with high equivalent plastic strains are observed which correspond to the nugget and the flow arm.",
publisher = "Vinca Institute of Nuclear Sciences",
journal = "Thermal Science",
title = "A coupled thermo-mechanical model of friction stir welding",
pages = "534-527",
number = "2",
volume = "16",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2029"
}

Veljić, D., Perović, M., Sedmak, A., Rakin, M., Trifunović, M. V., Bajić, N.,& Bajić, D.. (2012). A coupled thermo-mechanical model of friction stir welding. in Thermal Science
Vinca Institute of Nuclear Sciences., 16(2), 527-534.
https://hdl.handle.net/21.15107/rcub_technorep_2029

Veljić D, Perović M, Sedmak A, Rakin M, Trifunović MV, Bajić N, Bajić D. A coupled thermo-mechanical model of friction stir welding. in Thermal Science. 2012;16(2):527-534.
https://hdl.handle.net/21.15107/rcub_technorep_2029 .

Veljić, Darko, Perović, Milenko, Sedmak, Aleksandar, Rakin, Marko, Trifunović, Miroslav V., Bajić, Nikola, Bajić, Darko, "A coupled thermo-mechanical model of friction stir welding" in Thermal Science, 16, no. 2 (2012):527-534,
https://hdl.handle.net/21.15107/rcub_technorep_2029 .