TY  - PAT
AU  - Veljić, Darko
AU  - Bajić, Nikola
AU  - Rakin, Marko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6343
AB  - Prikazani pronalazak, alat od osam pari kalibrisanih valjaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice, se odnosi na konstrukciono rešenje alata za kalibraciju uske čelične trake i alata za formiranje punjene žice za izradu jezgra specijalne bazične elektrode za zavarivanje. To je alat koji poseduje 8 pari uzastopno postavljenih kalibrisanih valjaka, od kojih 5 pari kalibrisanih valjaka u kontinuitetu formira žleb duž uske čelične trake i 3 para kalibrisanih valjaka za zatvaranje u oblik cevi sa sučeonim podužnim spojem. Dobijena cev je prečnika 3,8mm i namenjena je za izradu punjene žice. Alat se ugrađuje na liniju za kalibraciju čelične trake i formiranje punjene žice. Dobijena punjena žica je namenjena za izradu jezgra specijalne bazične elektrode za zavarivanje čime se proširuje oblast tehnike u kome pronalazak ima značajnu primenu. Primena punjene žice za izradu jezgra elektrode omogućava kombinaciju rutilnog punjenja jezgra sa bazičnom oblogom elektrode, kao i mogućnost mikrolegiranja i legiranja metala šava preko jezgra elektrode.
T2  - Zavod za intelektualnu svojinu, sektor  za patente odeljenje za mašinstvo, elektrotehniku i opštu tehniku 990
T1  - Alat od osam pari kalibrisanih valljaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice
IS  - 021/13722-MP-2021/0085
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6343
ER  - 

@misc{
author = "Veljić, Darko and Bajić, Nikola and Rakin, Marko",
year = "2021",
abstract = "Prikazani pronalazak, alat od osam pari kalibrisanih valjaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice, se odnosi na konstrukciono rešenje alata za kalibraciju uske čelične trake i alata za formiranje punjene žice za izradu jezgra specijalne bazične elektrode za zavarivanje. To je alat koji poseduje 8 pari uzastopno postavljenih kalibrisanih valjaka, od kojih 5 pari kalibrisanih valjaka u kontinuitetu formira žleb duž uske čelične trake i 3 para kalibrisanih valjaka za zatvaranje u oblik cevi sa sučeonim podužnim spojem. Dobijena cev je prečnika 3,8mm i namenjena je za izradu punjene žice. Alat se ugrađuje na liniju za kalibraciju čelične trake i formiranje punjene žice. Dobijena punjena žica je namenjena za izradu jezgra specijalne bazične elektrode za zavarivanje čime se proširuje oblast tehnike u kome pronalazak ima značajnu primenu. Primena punjene žice za izradu jezgra elektrode omogućava kombinaciju rutilnog punjenja jezgra sa bazičnom oblogom elektrode, kao i mogućnost mikrolegiranja i legiranja metala šava preko jezgra elektrode.",
journal = "Zavod za intelektualnu svojinu, sektor  za patente odeljenje za mašinstvo, elektrotehniku i opštu tehniku 990",
title = "Alat od osam pari kalibrisanih valljaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice",
number = "021/13722-MP-2021/0085",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6343"
}

Veljić, D., Bajić, N.,& Rakin, M.. (2021). Alat od osam pari kalibrisanih valljaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice. in Zavod za intelektualnu svojinu, sektor  za patente odeljenje za mašinstvo, elektrotehniku i opštu tehniku 990(021/13722-MP-2021/0085).
https://hdl.handle.net/21.15107/rcub_technorep_6343

Veljić D, Bajić N, Rakin M. Alat od osam pari kalibrisanih valljaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice. in Zavod za intelektualnu svojinu, sektor  za patente odeljenje za mašinstvo, elektrotehniku i opštu tehniku 990. 2021;(021/13722-MP-2021/0085).
https://hdl.handle.net/21.15107/rcub_technorep_6343 .

Veljić, Darko, Bajić, Nikola, Rakin, Marko, "Alat od osam pari kalibrisanih valljaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice" in Zavod za intelektualnu svojinu, sektor  za patente odeljenje za mašinstvo, elektrotehniku i opštu tehniku 990, no. 021/13722-MP-2021/0085 (2021),
https://hdl.handle.net/21.15107/rcub_technorep_6343 .

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  - CONF
AU  - Mrdak, Mihailo
AU  - Pekez, Jasmina
AU  - Bajić, Nikola
AU  - Rakin, Marko
AU  - Veljić, Darko
AU  - Radosavljević, Zoran
AU  - Đurđev, Mića
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6338
PB  - Central and Eastern European Committee of Thermal Analysis and Calorimetry
C3  - 5th Central and Eastern European Conference on Thermal Analysis and Calorimetry & 14th Mediterranean Conference on Calorimetry and Thermal Analysis
T1  - Characterization of weld metal in welded microalloyed steel J55 made using a rutile electrode with a flux-cored wire core
SP  - 466
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6338
ER  - 

@conference{
author = "Mrdak, Mihailo and Pekez, Jasmina and Bajić, Nikola and Rakin, Marko and Veljić, Darko and Radosavljević, Zoran and Đurđev, Mića",
year = "2019",
publisher = "Central and Eastern European Committee of Thermal Analysis and Calorimetry",
journal = "5th Central and Eastern European Conference on Thermal Analysis and Calorimetry & 14th Mediterranean Conference on Calorimetry and Thermal Analysis",
title = "Characterization of weld metal in welded microalloyed steel J55 made using a rutile electrode with a flux-cored wire core",
pages = "466",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6338"
}

Mrdak, M., Pekez, J., Bajić, N., Rakin, M., Veljić, D., Radosavljević, Z.,& Đurđev, M.. (2019). Characterization of weld metal in welded microalloyed steel J55 made using a rutile electrode with a flux-cored wire core. in 5th Central and Eastern European Conference on Thermal Analysis and Calorimetry & 14th Mediterranean Conference on Calorimetry and Thermal Analysis
Central and Eastern European Committee of Thermal Analysis and Calorimetry., 466.
https://hdl.handle.net/21.15107/rcub_technorep_6338

Mrdak M, Pekez J, Bajić N, Rakin M, Veljić D, Radosavljević Z, Đurđev M. Characterization of weld metal in welded microalloyed steel J55 made using a rutile electrode with a flux-cored wire core. in 5th Central and Eastern European Conference on Thermal Analysis and Calorimetry & 14th Mediterranean Conference on Calorimetry and Thermal Analysis. 2019;:466.
https://hdl.handle.net/21.15107/rcub_technorep_6338 .

Mrdak, Mihailo, Pekez, Jasmina, Bajić, Nikola, Rakin, Marko, Veljić, Darko, Radosavljević, Zoran, Đurđev, Mića, "Characterization of weld metal in welded microalloyed steel J55 made using a rutile electrode with a flux-cored wire core" in 5th Central and Eastern European Conference on Thermal Analysis and Calorimetry & 14th Mediterranean Conference on Calorimetry and Thermal Analysis (2019):466,
https://hdl.handle.net/21.15107/rcub_technorep_6338 .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Veljić, Darko
AU  - Bajić, Nikola
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4273
AB  - Protective vacuum plasma spray VPS - NiCoCrAlY coating is used on sections of gas turbines to allow for longer and more reliable operation of sections exposed to aggressive effects of high temperature oxidation. Depositing of NiCoCrAlY alloy powder was done with the vacuum plasma spray system of the Plasma Technik - AG Companyon the A-2000 control unit using the plasma F4 gun. To test the mechanical properties and microstructure of the NiCoCrAlY coating, the powder was deposited on Č.4171 (X15Cr13 EN10027) steel substrates.To examine the microstructure of the coating in the heat-treated state, the powder was deposited on an IN738LC alloy substrate, which was pre-heated to a temperature of 750 to 800°C before deposition of the powder. The coating with the IN738LC alloy substrate was heat-treated at 1150°C for 2 hours in anargon shielded atmosphere. Mechanical testing of the microhardness of the coating was done using the HV0.3 method and the tensile bond strength using the tension method. The morphology of the powder particles and the morphology of the surface of the deposited coating were examined using a scanning electron microscope (SEM). The microstructure of coating layers in deposited state was tested on an optical microscope (OM). After thermal treatment, etching of the coating was done in the reagent CuSO4 + HCl aqueous solution. Analysis of the microstructure of the coating after etching was performed on the SEM, on the basis of which a score of the quality of the diffusion VPS - NiCoCrAlY coating was given.
AB  - Zaštitna vakuum plazma sprej VPS - NiCoCrAlY prevlaka se koriste na sekcijama gasnih turbina da bi se omogućio duži i pouzdaniji rad sekcijama izloženim agresivnom napadu visokotemperaturne oksidacije. Deponovanje praha od legure NiCoCrAlY urađeno je vakuum plazma sprej sistemom firme Plasma Technik - AG na upravljačkoj jedinici A-2000 sa plazma pištoljem F4. Za ispitivanje mehaničkih karakteristika i mikrostrukture NiCoCrAlY prevlake, prah je deponovan na substratima od čelika Č.4171 (X15Cr13 EN10027). Za ispitivanje mikrostrukture prevlake u termički obrađenom stanju, prah je deponovan na substratu od legure IN738LC, koji je pre depozicije praha bio predgrejan na temperaturi od 750 do 800°C. Prevlaka je sa substratom od legure IN738LC termički tretirana na 1150°C u trajanju od 2 sata u zaštitnoj atmosferi argona. Mehanička ispitivanja mikrotvrdoće prevlake urađena su metodom HV0.3 i zatezna čvrstoća spoja metodom na zatezanje. Morfologija čestica praha i morfologija površine deponovane prevlake ispitana je na skening elektronskom mikroskopu (SEM). Mikrostruktura slojeva prevlake u deponovanom stanju ispitana je na optičkom mikroskopu (OM). Posle termičke obrade sprovedeno je nagrizanje prevlake u reagensu CuSO4 + HCl vodeni rastvor. Analiza mikrostrukture prevlake posle nagrizanja urađena je na SEM-u, na osnovu čega se dala ocena kvaliteta difuzione VPS - NiCoCrAlY prevlake.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Characterization of vacuum plasma spray NiCoCrAlY coating resistant to high temperature oxidation
T1  - Karakterizacija vakuum plazma sprej prevlake NiCoCrAlY otporne na visokotemperaturnu oksidaciju
EP  - 341
IS  - 4
SP  - 336
VL  - 60
DO  - 10.5937/zasmat1904336M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Veljić, Darko and Bajić, Nikola",
year = "2019",
abstract = "Protective vacuum plasma spray VPS - NiCoCrAlY coating is used on sections of gas turbines to allow for longer and more reliable operation of sections exposed to aggressive effects of high temperature oxidation. Depositing of NiCoCrAlY alloy powder was done with the vacuum plasma spray system of the Plasma Technik - AG Companyon the A-2000 control unit using the plasma F4 gun. To test the mechanical properties and microstructure of the NiCoCrAlY coating, the powder was deposited on Č.4171 (X15Cr13 EN10027) steel substrates.To examine the microstructure of the coating in the heat-treated state, the powder was deposited on an IN738LC alloy substrate, which was pre-heated to a temperature of 750 to 800°C before deposition of the powder. The coating with the IN738LC alloy substrate was heat-treated at 1150°C for 2 hours in anargon shielded atmosphere. Mechanical testing of the microhardness of the coating was done using the HV0.3 method and the tensile bond strength using the tension method. The morphology of the powder particles and the morphology of the surface of the deposited coating were examined using a scanning electron microscope (SEM). The microstructure of coating layers in deposited state was tested on an optical microscope (OM). After thermal treatment, etching of the coating was done in the reagent CuSO4 + HCl aqueous solution. Analysis of the microstructure of the coating after etching was performed on the SEM, on the basis of which a score of the quality of the diffusion VPS - NiCoCrAlY coating was given., Zaštitna vakuum plazma sprej VPS - NiCoCrAlY prevlaka se koriste na sekcijama gasnih turbina da bi se omogućio duži i pouzdaniji rad sekcijama izloženim agresivnom napadu visokotemperaturne oksidacije. Deponovanje praha od legure NiCoCrAlY urađeno je vakuum plazma sprej sistemom firme Plasma Technik - AG na upravljačkoj jedinici A-2000 sa plazma pištoljem F4. Za ispitivanje mehaničkih karakteristika i mikrostrukture NiCoCrAlY prevlake, prah je deponovan na substratima od čelika Č.4171 (X15Cr13 EN10027). Za ispitivanje mikrostrukture prevlake u termički obrađenom stanju, prah je deponovan na substratu od legure IN738LC, koji je pre depozicije praha bio predgrejan na temperaturi od 750 do 800°C. Prevlaka je sa substratom od legure IN738LC termički tretirana na 1150°C u trajanju od 2 sata u zaštitnoj atmosferi argona. Mehanička ispitivanja mikrotvrdoće prevlake urađena su metodom HV0.3 i zatezna čvrstoća spoja metodom na zatezanje. Morfologija čestica praha i morfologija površine deponovane prevlake ispitana je na skening elektronskom mikroskopu (SEM). Mikrostruktura slojeva prevlake u deponovanom stanju ispitana je na optičkom mikroskopu (OM). Posle termičke obrade sprovedeno je nagrizanje prevlake u reagensu CuSO4 + HCl vodeni rastvor. Analiza mikrostrukture prevlake posle nagrizanja urađena je na SEM-u, na osnovu čega se dala ocena kvaliteta difuzione VPS - NiCoCrAlY prevlake.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Characterization of vacuum plasma spray NiCoCrAlY coating resistant to high temperature oxidation, Karakterizacija vakuum plazma sprej prevlake NiCoCrAlY otporne na visokotemperaturnu oksidaciju",
pages = "341-336",
number = "4",
volume = "60",
doi = "10.5937/zasmat1904336M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Veljić, D.,& Bajić, N.. (2019). Characterization of vacuum plasma spray NiCoCrAlY coating resistant to high temperature oxidation. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 60(4), 336-341.
https://doi.org/10.5937/zasmat1904336M

Mrdak M, Lačnjevac Č, Rakin M, Veljić D, Bajić N. Characterization of vacuum plasma spray NiCoCrAlY coating resistant to high temperature oxidation. in Zaštita materijala. 2019;60(4):336-341.
doi:10.5937/zasmat1904336M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Veljić, Darko, Bajić, Nikola, "Characterization of vacuum plasma spray NiCoCrAlY coating resistant to high temperature oxidation" in Zaštita materijala, 60, no. 4 (2019):336-341,
https://doi.org/10.5937/zasmat1904336M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Bajić, Nikola
AU  - Veljić, Darko
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4275
AB  - This paper presents the results of testing mechanical and structural characteristics of plasma spray coating Al2O328wt.%MgO. Metal oxide MgO in a complex oxide Al2O328wt.%MgO modifies the properties of Al2O3 ceramics by forming spinel MgAl2O4 with excellent biomedical characteristics. The coating layers were deposited by atmospheric plasma spraying process (APS) on steel substrates of stainless steel X15Cr13 (EN 1.4024). The aim of this study was to examine the effect of the strength of the plasma current (700A, 800A and 900A) on the mechanical properties of the Al2O3MgO coating, pore content and microstructure of the layers. Testing microhardness of the layers using the HV0.3 method, the bond strength using the tensile method and microstructure using optical microscopy (OM) and scanning electron microscopy (SEM) have confirmed that, by controlling the plasma current, layers of the coating system Al2O328wt.%MgO can be deposited with good mechanical and microstructural characteristics suitable for use in manufacture of implants.
AB  - U ovom radu su prikazani rezultati ispitivanja mehaničkih i strukturnih karakteristika plazma sprej prevlake Al2O328tež.%MgO. Metalni oksid MgO u kompleksnom oksidu Al2O328tež.%MgO modifikuje osobine Al2O3 keramike formiranjem spinela MgAl2O4 odličnih biomedicinskih karakteristika. Slojevi prevlake su deponovani atmosferski plazma sprej procesom (APS) na čeličnim podlogama od nerđajućeg čelika X15Cr13 (EN 1.4024). Cilj ovog rada je bio da se ispita efekat jačine plazma struje (700A, 800A i 900A) na mehaničke osobine prevlake Al2O3MgO, sadržaj pora i mikrostrukturu slojeva. Ispitivanja mikrotvrdoće slojeva metodama HV0.3, čvrstoće spoja zatezanjem i mikrostrukture optičkom mikroskopijom (OM) i skening elektronskom mikroskopijom (SEM) su potvrdila da se sa kontrolom plazma struje mogu deponovati slojevi sistema prevlake Al2O328tež.%MgO dobrih mehaničkih i mikrostrukturih karakteristika pogodnih za primenu u eksploataciji za proizvodnju implanata.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Characterization of plasma spray bioinert coating Al2O328wt.%MgO
T1  - Karakterizacija plazma sprej bioinertne prevlake Al2O328tež.%MgO
EP  - 49
IS  - 1
SP  - 44
VL  - 60
DO  - 10.5937/zasmat1901044M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Bajić, Nikola and Veljić, Darko",
year = "2019",
abstract = "This paper presents the results of testing mechanical and structural characteristics of plasma spray coating Al2O328wt.%MgO. Metal oxide MgO in a complex oxide Al2O328wt.%MgO modifies the properties of Al2O3 ceramics by forming spinel MgAl2O4 with excellent biomedical characteristics. The coating layers were deposited by atmospheric plasma spraying process (APS) on steel substrates of stainless steel X15Cr13 (EN 1.4024). The aim of this study was to examine the effect of the strength of the plasma current (700A, 800A and 900A) on the mechanical properties of the Al2O3MgO coating, pore content and microstructure of the layers. Testing microhardness of the layers using the HV0.3 method, the bond strength using the tensile method and microstructure using optical microscopy (OM) and scanning electron microscopy (SEM) have confirmed that, by controlling the plasma current, layers of the coating system Al2O328wt.%MgO can be deposited with good mechanical and microstructural characteristics suitable for use in manufacture of implants., U ovom radu su prikazani rezultati ispitivanja mehaničkih i strukturnih karakteristika plazma sprej prevlake Al2O328tež.%MgO. Metalni oksid MgO u kompleksnom oksidu Al2O328tež.%MgO modifikuje osobine Al2O3 keramike formiranjem spinela MgAl2O4 odličnih biomedicinskih karakteristika. Slojevi prevlake su deponovani atmosferski plazma sprej procesom (APS) na čeličnim podlogama od nerđajućeg čelika X15Cr13 (EN 1.4024). Cilj ovog rada je bio da se ispita efekat jačine plazma struje (700A, 800A i 900A) na mehaničke osobine prevlake Al2O3MgO, sadržaj pora i mikrostrukturu slojeva. Ispitivanja mikrotvrdoće slojeva metodama HV0.3, čvrstoće spoja zatezanjem i mikrostrukture optičkom mikroskopijom (OM) i skening elektronskom mikroskopijom (SEM) su potvrdila da se sa kontrolom plazma struje mogu deponovati slojevi sistema prevlake Al2O328tež.%MgO dobrih mehaničkih i mikrostrukturih karakteristika pogodnih za primenu u eksploataciji za proizvodnju implanata.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Characterization of plasma spray bioinert coating Al2O328wt.%MgO, Karakterizacija plazma sprej bioinertne prevlake Al2O328tež.%MgO",
pages = "49-44",
number = "1",
volume = "60",
doi = "10.5937/zasmat1901044M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Bajić, N.,& Veljić, D.. (2019). Characterization of plasma spray bioinert coating Al2O328wt.%MgO. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 60(1), 44-49.
https://doi.org/10.5937/zasmat1901044M

Mrdak M, Lačnjevac Č, Rakin M, Bajić N, Veljić D. Characterization of plasma spray bioinert coating Al2O328wt.%MgO. in Zaštita materijala. 2019;60(1):44-49.
doi:10.5937/zasmat1901044M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Bajić, Nikola, Veljić, Darko, "Characterization of plasma spray bioinert coating Al2O328wt.%MgO" in Zaštita materijala, 60, no. 1 (2019):44-49,
https://doi.org/10.5937/zasmat1901044M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Bajić, Nikola
AU  - Veljić, Darko
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4276
AB  - ZrO25CaO is a versatile class of material that can be sintered or plasma spray deposited in combination with other materials on the implant substrate. Due to brittleness the organic ceramic hydroxyapatite Ca10(PO4)6(OH)2 - (HA) is not suitable for use as a separate material in the process of making implants. In order to improve the mechanical characteristics and osteoconductivity, to HA ceramics added are dual systems of oxide solid solutions, of which one is also ZrO25CaO. Ceramics ZrO2-CaO(95%-5%) as a biomaterial facilitates osteoconductivity in new bone formation around the implant. This paper represents the need to develop a system of ZrO25CaO/NiCrAl coatings that will with their mechanical and structural characteristics find application on implant parts. In this context, using the atmospheric plasma spray process deposited were the ZrO25CaO/NiCrAl coatings system on stainless steel substrates X15Cr13 (EN 1.4024). Analysis of the morphology of the powder particles and the surface of the ZrO25CaO coatings was carried out on the SEM. The microstructure of the layers of the coatings system was analyzed on the OM. Mechanical properties of the coating were determined by examining the microhardness using the HV0.3 method and bond strength by tensile testing according to the standard (ASTMC633-1).
AB  - ZrO25CaO je višenamenska klasa materijala koja može da se sinteruje ili plazma sprej deponuje u kombinaciji sa drugim materijalima na podlogama implantata. Zbog krtosti organska keramika hidroksiapatit Ca10(PO4)6(OH)2 - (HA) nije pogodna za primenu kao zaseban materijal u procesu izrade implantata. U cilju poboljšanja osteokonduktivnosti i mehaničkih karakteristika, keramici HA se dodavaju dvojni sistemi čvrstih rastvora oksida od kojih je jedan i ZrO25CaO. Keramika ZrO2-CaO(95%-5%) kao biomaterijal olakšava osteokonduktivnost u novom formiranju kostiju oko implantata. Ovaj rad predstavlja potrebu za izradom sistema ZrO25CaO/NiCrAl prevlaka koje će po svojim mehaničkim i strukturnim karakteristikama naći primenu na delovima implantata. U tom kontekstu atmosferskim plazma sprej procesom deponovan je sistem prevlaka ZrO25CaO/NiCrAl na čeličnim podlogama od nerđajućeg čelika X15Cr13 (EN 1.4024). Analiza morfologije čestica praha i površine prevlaka ZrO25CaO sprovedena je na SEM-u. Mikrostruktura slojeva sistema prevlaka ispitana je na OM-u. Mehaničke karakteristike prevlaka su sprovedene ispitivanjem mikrotvrdoće metodom HV0.3 i čvrstoće spoja ispitivanjem na zatezanje po standardu (ASTMC633-1).
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Mechanical properties and microstructure of the ZrO25CaO/NiCrAl coating system
T1  - Mehaničke osobine i mikrostruktura sistema prevlaka ZrO25CaO/NiCrAl
EP  - 151
IS  - 2
SP  - 147
VL  - 60
DO  - 10.5937/zasmat1902147M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Bajić, Nikola and Veljić, Darko",
year = "2019",
abstract = "ZrO25CaO is a versatile class of material that can be sintered or plasma spray deposited in combination with other materials on the implant substrate. Due to brittleness the organic ceramic hydroxyapatite Ca10(PO4)6(OH)2 - (HA) is not suitable for use as a separate material in the process of making implants. In order to improve the mechanical characteristics and osteoconductivity, to HA ceramics added are dual systems of oxide solid solutions, of which one is also ZrO25CaO. Ceramics ZrO2-CaO(95%-5%) as a biomaterial facilitates osteoconductivity in new bone formation around the implant. This paper represents the need to develop a system of ZrO25CaO/NiCrAl coatings that will with their mechanical and structural characteristics find application on implant parts. In this context, using the atmospheric plasma spray process deposited were the ZrO25CaO/NiCrAl coatings system on stainless steel substrates X15Cr13 (EN 1.4024). Analysis of the morphology of the powder particles and the surface of the ZrO25CaO coatings was carried out on the SEM. The microstructure of the layers of the coatings system was analyzed on the OM. Mechanical properties of the coating were determined by examining the microhardness using the HV0.3 method and bond strength by tensile testing according to the standard (ASTMC633-1)., ZrO25CaO je višenamenska klasa materijala koja može da se sinteruje ili plazma sprej deponuje u kombinaciji sa drugim materijalima na podlogama implantata. Zbog krtosti organska keramika hidroksiapatit Ca10(PO4)6(OH)2 - (HA) nije pogodna za primenu kao zaseban materijal u procesu izrade implantata. U cilju poboljšanja osteokonduktivnosti i mehaničkih karakteristika, keramici HA se dodavaju dvojni sistemi čvrstih rastvora oksida od kojih je jedan i ZrO25CaO. Keramika ZrO2-CaO(95%-5%) kao biomaterijal olakšava osteokonduktivnost u novom formiranju kostiju oko implantata. Ovaj rad predstavlja potrebu za izradom sistema ZrO25CaO/NiCrAl prevlaka koje će po svojim mehaničkim i strukturnim karakteristikama naći primenu na delovima implantata. U tom kontekstu atmosferskim plazma sprej procesom deponovan je sistem prevlaka ZrO25CaO/NiCrAl na čeličnim podlogama od nerđajućeg čelika X15Cr13 (EN 1.4024). Analiza morfologije čestica praha i površine prevlaka ZrO25CaO sprovedena je na SEM-u. Mikrostruktura slojeva sistema prevlaka ispitana je na OM-u. Mehaničke karakteristike prevlaka su sprovedene ispitivanjem mikrotvrdoće metodom HV0.3 i čvrstoće spoja ispitivanjem na zatezanje po standardu (ASTMC633-1).",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Mechanical properties and microstructure of the ZrO25CaO/NiCrAl coating system, Mehaničke osobine i mikrostruktura sistema prevlaka ZrO25CaO/NiCrAl",
pages = "151-147",
number = "2",
volume = "60",
doi = "10.5937/zasmat1902147M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Bajić, N.,& Veljić, D.. (2019). Mechanical properties and microstructure of the ZrO25CaO/NiCrAl coating system. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 60(2), 147-151.
https://doi.org/10.5937/zasmat1902147M

Mrdak M, Lačnjevac Č, Rakin M, Bajić N, Veljić D. Mechanical properties and microstructure of the ZrO25CaO/NiCrAl coating system. in Zaštita materijala. 2019;60(2):147-151.
doi:10.5937/zasmat1902147M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Bajić, Nikola, Veljić, Darko, "Mechanical properties and microstructure of the ZrO25CaO/NiCrAl coating system" in Zaštita materijala, 60, no. 2 (2019):147-151,
https://doi.org/10.5937/zasmat1902147M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Veljić, Darko
AU  - Bajić, Nikola
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4277
AB  - Molybdenum coatings due to their excellent wear resistant properties and sliding characteristics under dry friction conditions are often used in applications to resist friction and dry sliding. Since molybdenum metal is susceptible to oxidation, in this study, the molybdenum coating layers were successfully deposited at low pressure inert gas Ar using vacuum plasma spray technology (VPS). Characterization of the Mo coating was performed by measuring the microhardness of the coating layers using the Vickers HV0.3 method, the bond strength by tensile testing and the microstructure by optical microscopy (OM) and scanning electron microscopy (SEM). The microstructure of the coating layers was tested in deposited stateand after etching. The etching reagent used was NH3·H2O and H2O2 with a volume ratio of 1:2. The results showed that the coating has good mechanical properties, microhardness and high adhesion/cohesion strength. Layers of VPS - Mo coatings were composed of well-melted powder particles, partially unmelted particles with a good bond in the coating layers and micropores with a share below 0.5%. It was found that the microstructure of the coating consists mainly of lamellar structure and columnar crystal Mo grains. Tests have shown that the VPS - Mo coating layers have mechanical characteristics and a microstructure which fully enables the use of the coating on surfaces of parts which are required to have good sliding properties, resistance to wear and corrosion.
AB  - Prevlake molibdena se zbog svojih odličnih osobina na habanje i kliznih svojstva u uslovima suvog trenja često koriste u aplikacijama da se odupru trenju i suvom klizanju. Pošto je molibden metal osetljiv na oksidaciju, u ovoj studiji slojevi prevlake molibdena su uspešno deponovani na niskom pritisku inertnog gasa Ar vacuum plazma sprej tehnologijom (VPS). Karakterizacija prevlake Mo je izvršena merenjem mikrotvrdoće slojeva prevlake metodom Vickers HV0.3, čvrstoće spoja ispitivanjem na zatezanje i mikrostrukture metodom optičke mikroskopije (OM) i skening elektronske mikroskopije (SEM). Mikrostruktura slojeva prevlake je ispitana u deponovanom stanju i posle nagrizanja. Za nagrizanje se koristio reagens NH3·H2O i H2O2 sa zapreminskim odnosom 1:2. Dobijeni rezultati su pokazali da prevlaka ima dobre mehaničke karakteristike, mikrotvrdoću i visoku adheziono / kohezionu čvrstoću. Slojevi VPS - Mo prevlake su se sastojali od dobro istopljenih čestica praha, delimično neistopljenih čestica sa dobrom vezom u slojevima prevlake i mikro pora sa udelom ispod 0,5%. Utvrđeno je da se mikrostruktura prevlake uglavnom sastoji od lamelarne strukture i stubastih kristalnih zrna Mo. Ispitivanja su pokazala da VPS - Mo slojevi prevlake imaju mehaničke karakteristike i mikrostrukturu koje u potpunosti omogućavaju primenu prevlake na površinama delova od kojih se zahteva da imaju dobra klizna svojstva, otpornost na habanje i koroziju.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Mechanical properties and microstructure of molybdenum coating layers deposited vacuum plasma spray process
T1  - Mehanička svojstva i mikrostruktura slojeva prevlake molibdena deponovane vakuum plazma sprej procesom
EP  - 276
IS  - 3
SP  - 271
VL  - 60
DO  - 10.5937/zasmat1903271M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Veljić, Darko and Bajić, Nikola",
year = "2019",
abstract = "Molybdenum coatings due to their excellent wear resistant properties and sliding characteristics under dry friction conditions are often used in applications to resist friction and dry sliding. Since molybdenum metal is susceptible to oxidation, in this study, the molybdenum coating layers were successfully deposited at low pressure inert gas Ar using vacuum plasma spray technology (VPS). Characterization of the Mo coating was performed by measuring the microhardness of the coating layers using the Vickers HV0.3 method, the bond strength by tensile testing and the microstructure by optical microscopy (OM) and scanning electron microscopy (SEM). The microstructure of the coating layers was tested in deposited stateand after etching. The etching reagent used was NH3·H2O and H2O2 with a volume ratio of 1:2. The results showed that the coating has good mechanical properties, microhardness and high adhesion/cohesion strength. Layers of VPS - Mo coatings were composed of well-melted powder particles, partially unmelted particles with a good bond in the coating layers and micropores with a share below 0.5%. It was found that the microstructure of the coating consists mainly of lamellar structure and columnar crystal Mo grains. Tests have shown that the VPS - Mo coating layers have mechanical characteristics and a microstructure which fully enables the use of the coating on surfaces of parts which are required to have good sliding properties, resistance to wear and corrosion., Prevlake molibdena se zbog svojih odličnih osobina na habanje i kliznih svojstva u uslovima suvog trenja često koriste u aplikacijama da se odupru trenju i suvom klizanju. Pošto je molibden metal osetljiv na oksidaciju, u ovoj studiji slojevi prevlake molibdena su uspešno deponovani na niskom pritisku inertnog gasa Ar vacuum plazma sprej tehnologijom (VPS). Karakterizacija prevlake Mo je izvršena merenjem mikrotvrdoće slojeva prevlake metodom Vickers HV0.3, čvrstoće spoja ispitivanjem na zatezanje i mikrostrukture metodom optičke mikroskopije (OM) i skening elektronske mikroskopije (SEM). Mikrostruktura slojeva prevlake je ispitana u deponovanom stanju i posle nagrizanja. Za nagrizanje se koristio reagens NH3·H2O i H2O2 sa zapreminskim odnosom 1:2. Dobijeni rezultati su pokazali da prevlaka ima dobre mehaničke karakteristike, mikrotvrdoću i visoku adheziono / kohezionu čvrstoću. Slojevi VPS - Mo prevlake su se sastojali od dobro istopljenih čestica praha, delimično neistopljenih čestica sa dobrom vezom u slojevima prevlake i mikro pora sa udelom ispod 0,5%. Utvrđeno je da se mikrostruktura prevlake uglavnom sastoji od lamelarne strukture i stubastih kristalnih zrna Mo. Ispitivanja su pokazala da VPS - Mo slojevi prevlake imaju mehaničke karakteristike i mikrostrukturu koje u potpunosti omogućavaju primenu prevlake na površinama delova od kojih se zahteva da imaju dobra klizna svojstva, otpornost na habanje i koroziju.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Mechanical properties and microstructure of molybdenum coating layers deposited vacuum plasma spray process, Mehanička svojstva i mikrostruktura slojeva prevlake molibdena deponovane vakuum plazma sprej procesom",
pages = "276-271",
number = "3",
volume = "60",
doi = "10.5937/zasmat1903271M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Veljić, D.,& Bajić, N.. (2019). Mechanical properties and microstructure of molybdenum coating layers deposited vacuum plasma spray process. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 60(3), 271-276.
https://doi.org/10.5937/zasmat1903271M

Mrdak M, Lačnjevac Č, Rakin M, Veljić D, Bajić N. Mechanical properties and microstructure of molybdenum coating layers deposited vacuum plasma spray process. in Zaštita materijala. 2019;60(3):271-276.
doi:10.5937/zasmat1903271M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Veljić, Darko, Bajić, Nikola, "Mechanical properties and microstructure of molybdenum coating layers deposited vacuum plasma spray process" in Zaštita materijala, 60, no. 3 (2019):271-276,
https://doi.org/10.5937/zasmat1903271M . .

TY  - CONF
AU  - Mrdak, Mihailo
AU  - Rakin, Marko
AU  - Bajić, Nikola
AU  - Veljić, Darko
AU  - Pekez, Jasmina
AU  - Karastojković, Zoran
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6337
AB  - The plasma spray coatings are subject to high influence of surface loads, corrosion, and temperatures
which cause damage in the form of separation of the coating from the substrate or flacking of the coating from
the substrate edges. Adhesion is the main factor that opposes the influence of the external loads, and defines the
quality of the bond of the coating with the substrate. Each type of coating has a determined quality of adhesion
as per appropriate standard in order to meet functional properties during operation.
There is no universal coating test for all types of the coatings, the test is chosen depending on the technology
used for the production of the coating, the type of material from which it was made and its thickness. One of the
many tests that are used for assessment of adhesion / cohesion strength of plasma spray coatings is the scratch
test. The aim of this paper was to evaluate the cohesive / adhesive strength of the plasma spray
Ni22Cr10Al1Yalloycoating. The testing was conducted using the Rockwell C diamond indenter with a tip radius
of 200 µm. The results showed that the scratch test is an efficient method for assessment of adhesion and
cohesion of plasma spray coatings.
PB  - University of Novi Sad Technical faculty “Mihajlo Pupin” Zrenjanin, Republic of Serbia
C3  - VIII International Conference Industrial Engineering and Environmental Protection
T1  - Determining the adhesion / cohesion strength of plasma spray coatings using the Rockwell - c method
EP  - 122
SP  - 119
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6337
ER  - 

@conference{
author = "Mrdak, Mihailo and Rakin, Marko and Bajić, Nikola and Veljić, Darko and Pekez, Jasmina and Karastojković, Zoran",
year = "2018",
abstract = "The plasma spray coatings are subject to high influence of surface loads, corrosion, and temperatures
which cause damage in the form of separation of the coating from the substrate or flacking of the coating from
the substrate edges. Adhesion is the main factor that opposes the influence of the external loads, and defines the
quality of the bond of the coating with the substrate. Each type of coating has a determined quality of adhesion
as per appropriate standard in order to meet functional properties during operation.
There is no universal coating test for all types of the coatings, the test is chosen depending on the technology
used for the production of the coating, the type of material from which it was made and its thickness. One of the
many tests that are used for assessment of adhesion / cohesion strength of plasma spray coatings is the scratch
test. The aim of this paper was to evaluate the cohesive / adhesive strength of the plasma spray
Ni22Cr10Al1Yalloycoating. The testing was conducted using the Rockwell C diamond indenter with a tip radius
of 200 µm. The results showed that the scratch test is an efficient method for assessment of adhesion and
cohesion of plasma spray coatings.",
publisher = "University of Novi Sad Technical faculty “Mihajlo Pupin” Zrenjanin, Republic of Serbia",
journal = "VIII International Conference Industrial Engineering and Environmental Protection",
title = "Determining the adhesion / cohesion strength of plasma spray coatings using the Rockwell - c method",
pages = "122-119",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6337"
}

Mrdak, M., Rakin, M., Bajić, N., Veljić, D., Pekez, J.,& Karastojković, Z.. (2018). Determining the adhesion / cohesion strength of plasma spray coatings using the Rockwell - c method. in VIII International Conference Industrial Engineering and Environmental Protection
University of Novi Sad Technical faculty “Mihajlo Pupin” Zrenjanin, Republic of Serbia., 119-122.
https://hdl.handle.net/21.15107/rcub_technorep_6337

Mrdak M, Rakin M, Bajić N, Veljić D, Pekez J, Karastojković Z. Determining the adhesion / cohesion strength of plasma spray coatings using the Rockwell - c method. in VIII International Conference Industrial Engineering and Environmental Protection. 2018;:119-122.
https://hdl.handle.net/21.15107/rcub_technorep_6337 .

Mrdak, Mihailo, Rakin, Marko, Bajić, Nikola, Veljić, Darko, Pekez, Jasmina, Karastojković, Zoran, "Determining the adhesion / cohesion strength of plasma spray coatings using the Rockwell - c method" in VIII International Conference Industrial Engineering and Environmental Protection (2018):119-122,
https://hdl.handle.net/21.15107/rcub_technorep_6337 .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Bajić, Nikola
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3821
AB  - Tantalum is a very popular material for the industry as a whole because of very important characteristics such as: high melting point, significant thermal and electrical conductivity, high toughness and resistance to corrosion and good biocompatibility. Since the tantalum metal is sensitive to O, N and H gases, tantalum coating layers are deposited only using the vacuum plasma spray process (VPS), which has, in the past few years been used successfully for preparing coatings which are widely used in the preparation of metal implants. The aim of this paper was to, at a low pressure inert gas eliminate the influence of the surrounding atmosphere on the melted Ta powder particles and produce coatings with mechanical and structural characteristics which will find application in biomedicine. For depositing the coating a commercial tantalum powder AMPERIT® 151065 grain size of 10 - 30 μm was used. The powder was deposited with a plasma F4 gun at a distance of substrates at 300 mm. The Ta coating layers were deposited with a thickness of 60 to 70 μm on steel substrates. As the plasma gas used was a mixture of Ar and He inert gases. The microhardness of the coating was tested using the HV0.3 method and the tensile strength of the coatings bond was tested by the tensile method in accordance with the ASTM C633-1 standard. The microstructure of the coating in deposited state and after etching was studied on an optical microscope (OM) and scanning electron microscope (SEM). Etching the coating was carried out in the reagent which consisted of two parts of nitric acid, two parts hydrofluoric acid, and five parts water (2HNO3: 2HF: 5H2O). The structure of the coating consists solely of a tough αTa phase with a body centered cubic lattice. Tests have shown that layers of VPS - Ta coatings have the microstructure and mechanical properties which completely support the use of the coating in the process of making implants.
AB  - Tantal je veoma atraktivan materijal za industriju u celini zbog veoma bitnih osobina kao što su: visoka temperatura topljenja, značajna toplotna i električna provodljivost, visoka žilavost i otpornost na koroziju i dobra biokompatibilnost. Pošto je tantal metal osetljiv na gasove O, N i H, slojevi prevlake tantala se isključivo deponuju vakuum plazma sprej procesom (VPS), koji se u poslednjih nekoliko godina uspešno koristi za izradu prevlaka koje imaju široku primenu u izradi metalnih implanata. Cilj rada bio je da se na niskom pritisku inertnog gasa eliminiše uticaj okolne atmosfere na istopljene čestice praha Ta i proizvedu prevlake mehaničkih i strukturnih karakteristika koje će naći primenu u biomedicini. Za deponovanje prevlake koristio se komercijalni prah tantala AMPERIT® 151.065 granulacije od 10 - 30µm. Prah je deponovan sa plazma pištoljem F4 na odstojanju podloge od 300 mm. Slojevi Ta prevlaka su deponovani sa debljinom od 60 do 70µm na čeličnim podlogama. Kao plazma gas koristila se mešavina inertnih gasova Ar i He. Mikrotvrdoća prevlake ispitana je metodom HV0.3 a zatezna čvrstoća spoja prevlake ispitana je metodom na zatezanje u skladu sa standardom ASTM C633-1. Mikrostruktura prevlake u deponovnom stanju i u stanju posle nagrizanja ispitana je na optičkom mikroskopu (OM) i na skening elektronskom mikroskopu (SEM). Nagrizanje prevlake sprovedeno je u reagensu koji se sastojao od dva dela azotne kiseline, dva dela fluorovodonične kiseline i pet delova vode (2HNO3 : 2HF : 5H2O). Struktura prevlake se isključivo sastoji od žilave α-Ta faze sa zapreminski centriranom kubnom rešetkom. Ispitivanja su pokazala da slojevi VPS - Ta prevlake imaju mikrostrukturu i mehaničke karakteristike koje u potpunosti omogućavaju primenu prevlake u procesu izrade implanata.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Characterization of tantalum coatings deposited using vacuum plasma spray process
T1  - Karakterizacija tantal prevlake deponovane vakuum plazma sprej procesom
EP  - 494
IS  - 4
SP  - 489
VL  - 59
DO  - 10.5937/zasmat1804489M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Bajić, Nikola",
year = "2018",
abstract = "Tantalum is a very popular material for the industry as a whole because of very important characteristics such as: high melting point, significant thermal and electrical conductivity, high toughness and resistance to corrosion and good biocompatibility. Since the tantalum metal is sensitive to O, N and H gases, tantalum coating layers are deposited only using the vacuum plasma spray process (VPS), which has, in the past few years been used successfully for preparing coatings which are widely used in the preparation of metal implants. The aim of this paper was to, at a low pressure inert gas eliminate the influence of the surrounding atmosphere on the melted Ta powder particles and produce coatings with mechanical and structural characteristics which will find application in biomedicine. For depositing the coating a commercial tantalum powder AMPERIT® 151065 grain size of 10 - 30 μm was used. The powder was deposited with a plasma F4 gun at a distance of substrates at 300 mm. The Ta coating layers were deposited with a thickness of 60 to 70 μm on steel substrates. As the plasma gas used was a mixture of Ar and He inert gases. The microhardness of the coating was tested using the HV0.3 method and the tensile strength of the coatings bond was tested by the tensile method in accordance with the ASTM C633-1 standard. The microstructure of the coating in deposited state and after etching was studied on an optical microscope (OM) and scanning electron microscope (SEM). Etching the coating was carried out in the reagent which consisted of two parts of nitric acid, two parts hydrofluoric acid, and five parts water (2HNO3: 2HF: 5H2O). The structure of the coating consists solely of a tough αTa phase with a body centered cubic lattice. Tests have shown that layers of VPS - Ta coatings have the microstructure and mechanical properties which completely support the use of the coating in the process of making implants., Tantal je veoma atraktivan materijal za industriju u celini zbog veoma bitnih osobina kao što su: visoka temperatura topljenja, značajna toplotna i električna provodljivost, visoka žilavost i otpornost na koroziju i dobra biokompatibilnost. Pošto je tantal metal osetljiv na gasove O, N i H, slojevi prevlake tantala se isključivo deponuju vakuum plazma sprej procesom (VPS), koji se u poslednjih nekoliko godina uspešno koristi za izradu prevlaka koje imaju široku primenu u izradi metalnih implanata. Cilj rada bio je da se na niskom pritisku inertnog gasa eliminiše uticaj okolne atmosfere na istopljene čestice praha Ta i proizvedu prevlake mehaničkih i strukturnih karakteristika koje će naći primenu u biomedicini. Za deponovanje prevlake koristio se komercijalni prah tantala AMPERIT® 151.065 granulacije od 10 - 30µm. Prah je deponovan sa plazma pištoljem F4 na odstojanju podloge od 300 mm. Slojevi Ta prevlaka su deponovani sa debljinom od 60 do 70µm na čeličnim podlogama. Kao plazma gas koristila se mešavina inertnih gasova Ar i He. Mikrotvrdoća prevlake ispitana je metodom HV0.3 a zatezna čvrstoća spoja prevlake ispitana je metodom na zatezanje u skladu sa standardom ASTM C633-1. Mikrostruktura prevlake u deponovnom stanju i u stanju posle nagrizanja ispitana je na optičkom mikroskopu (OM) i na skening elektronskom mikroskopu (SEM). Nagrizanje prevlake sprovedeno je u reagensu koji se sastojao od dva dela azotne kiseline, dva dela fluorovodonične kiseline i pet delova vode (2HNO3 : 2HF : 5H2O). Struktura prevlake se isključivo sastoji od žilave α-Ta faze sa zapreminski centriranom kubnom rešetkom. Ispitivanja su pokazala da slojevi VPS - Ta prevlake imaju mikrostrukturu i mehaničke karakteristike koje u potpunosti omogućavaju primenu prevlake u procesu izrade implanata.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Characterization of tantalum coatings deposited using vacuum plasma spray process, Karakterizacija tantal prevlake deponovane vakuum plazma sprej procesom",
pages = "494-489",
number = "4",
volume = "59",
doi = "10.5937/zasmat1804489M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M.,& Bajić, N.. (2018). Characterization of tantalum coatings deposited using vacuum plasma spray process. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 59(4), 489-494.
https://doi.org/10.5937/zasmat1804489M

Mrdak M, Lačnjevac Č, Rakin M, Bajić N. Characterization of tantalum coatings deposited using vacuum plasma spray process. in Zaštita materijala. 2018;59(4):489-494.
doi:10.5937/zasmat1804489M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Bajić, Nikola, "Characterization of tantalum coatings deposited using vacuum plasma spray process" in Zaštita materijala, 59, no. 4 (2018):489-494,
https://doi.org/10.5937/zasmat1804489M . .

TY  - JOUR
AU  - Veljić, Darko
AU  - Međo, Bojan
AU  - Rakin, Marko
AU  - Radosavljević, Zoran M.
AU  - Bajić, Nikola
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3439
AB  - Temperature, plastic strain and heat generation during the plunge stage of the friction stir welding of high-strength aluminum alloys 2024 T3 and 2024 T351 are considered in this work. The plunging of the tool into the material is done at different rotating speeds. A 3-D finite element model for thermomechanical simulation is developed. It is based on arbitrary Lagrangian-Eulerian formulation, and Johnson-Cook material law is used for modelling of material behaviour. From comparison of the numerical results for alloys 2024 T3 and 2024 T351, it can be seen that the former has more intensive heat generation from the plastic deformation, due to its higher strength. Friction heat generation is only slightly dfferent for the two alloys. Therefore, temperatures in the working plate are higher in the alloy 2024 T3 for the same parameters of the plunge stage. Equivalent plastic strain is higher for 2024 T351 alloy, and the highest values are determined under the tool shoulder and around the tool pin. For the alloy 2024 T3, equivalent plastic strain is the highest in the influence zone of the tool pin.
PB  - Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd
T2  - Thermal Science
T1  - Analysis of the tool plunge in friction stir welding comparison of aluminum alloys 2024 t3 and 2024 t351
EP  - 254
IS  - 1
SP  - 247
VL  - 20
DO  - 10.2298/TSCI150313059V
ER  - 

@article{
author = "Veljić, Darko and Međo, Bojan and Rakin, Marko and Radosavljević, Zoran M. and Bajić, Nikola",
year = "2016",
abstract = "Temperature, plastic strain and heat generation during the plunge stage of the friction stir welding of high-strength aluminum alloys 2024 T3 and 2024 T351 are considered in this work. The plunging of the tool into the material is done at different rotating speeds. A 3-D finite element model for thermomechanical simulation is developed. It is based on arbitrary Lagrangian-Eulerian formulation, and Johnson-Cook material law is used for modelling of material behaviour. From comparison of the numerical results for alloys 2024 T3 and 2024 T351, it can be seen that the former has more intensive heat generation from the plastic deformation, due to its higher strength. Friction heat generation is only slightly dfferent for the two alloys. Therefore, temperatures in the working plate are higher in the alloy 2024 T3 for the same parameters of the plunge stage. Equivalent plastic strain is higher for 2024 T351 alloy, and the highest values are determined under the tool shoulder and around the tool pin. For the alloy 2024 T3, equivalent plastic strain is the highest in the influence zone of the tool pin.",
publisher = "Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd",
journal = "Thermal Science",
title = "Analysis of the tool plunge in friction stir welding comparison of aluminum alloys 2024 t3 and 2024 t351",
pages = "254-247",
number = "1",
volume = "20",
doi = "10.2298/TSCI150313059V"
}

Veljić, D., Međo, B., Rakin, M., Radosavljević, Z. M.,& Bajić, N.. (2016). Analysis of the tool plunge in friction stir welding comparison of aluminum alloys 2024 t3 and 2024 t351. in Thermal Science
Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd., 20(1), 247-254.
https://doi.org/10.2298/TSCI150313059V

Veljić D, Međo B, Rakin M, Radosavljević ZM, Bajić N. Analysis of the tool plunge in friction stir welding comparison of aluminum alloys 2024 t3 and 2024 t351. in Thermal Science. 2016;20(1):247-254.
doi:10.2298/TSCI150313059V .

Veljić, Darko, Međo, Bojan, Rakin, Marko, Radosavljević, Zoran M., Bajić, Nikola, "Analysis of the tool plunge in friction stir welding comparison of aluminum alloys 2024 t3 and 2024 t351" in Thermal Science, 20, no. 1 (2016):247-254,
https://doi.org/10.2298/TSCI150313059V . .

TY  - JOUR
AU  - Veljić, Darko
AU  - Sedmak, Aleksandar
AU  - Rakin, Marko
AU  - Radović, Nenad
AU  - Popović, Negica
AU  - Daşcău, Horia
AU  - Bajić, Nikola
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2893
AB  - U savremenoj industrijskoj proizvodnji, svaki proizvodni proces treba da bude ispitan u pogledu uticaja na životnu sredinu. Za svaku kompaniju koja investira u novi proces je od značaja pažljivo razmatranje HSE (Health, Safety and Environment) problema na radnom mestu. Zavarivanje trenjem sa mešanjem nudi brojne prednosti u pogledu zaštite zdravlja, životne sredine i bezbednosti na radu u odnosu na druge procese zavarivanja zasnovane na primeni električnog luka. Elektrolučno zavarivanje proizvodi čitav spek-tar ultraljubičastog zra čenja koje je štetno po čovekovo zdravlje, pre svega oči i kožu. Izlaganje ovom zračenju bez adekvatne zaštite može dovesti do ozbiljnih povreda. Ukoliko se ne koriste odgovarajuće mere zaštite, zavarivač vrlo lako može dobiti opekotine. Ovo je naročito izraženo kod elektrolučnog zavarivanja aluminijuma, gde je zbog velike provodljivosti materijala potrebno koristiti električni luk veće energije i čija površina ima veću refleksiju od čelika. Ovaj rad govori o FSW procesu zavarivanja i njegovim prednostima u odnosu na elektrolu čne postupke zavarivanja, sa posebnim osvrtom na zaštitu zdravlja, životne sredine i bezbednosti na radu.
AB  - In modern industrial production, every manufacturing and assembly process should be assessed with respect to its influence on the environment. For a company that invests in a new process, a careful analysis of HSE problems (Health, Safety and Environment) is very important. Friction stir welding (FSW) process offers numerous advantages regarding health protection, environmental effects and work safety in comparison with other welding procedures, such as arc welding. Arc welding produces a broad spec-trum of UV radiation, harmful for human health (skin, eyes). Exposure to this radiation without an adequate protection can lead to severe injuries. If appropriate protective measures are undertaken, the welder can easily be exposed to heat injuries. This is especially pronounced for arc welding of aluminium alloys, because high material conductivity of Al requires a high-energy arc, and also because its surface has more pronounced reflection than steel. This work deals with the FSW welding process and its advantages in comparison with arc welding processes with respect to health protection, environmental problems and work safety.
PB  - Society for Structural Integrity and Life (DIVK)
T2  - Structural Integrity and Life
T1  - Prednosti zavarivanja trenjem sa mešanjem u odnosu na elektrolučno zavarivanje - zaštita zdravlja i životne sredine i bezbednost na radu
T1  - Advantages of friction stir welding over arc welding with respect to health and environmental protection and work safety
EP  - 116
IS  - 2
SP  - 111
VL  - 15
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2893
ER  - 

@article{
author = "Veljić, Darko and Sedmak, Aleksandar and Rakin, Marko and Radović, Nenad and Popović, Negica and Daşcău, Horia and Bajić, Nikola",
year = "2015",
abstract = "U savremenoj industrijskoj proizvodnji, svaki proizvodni proces treba da bude ispitan u pogledu uticaja na životnu sredinu. Za svaku kompaniju koja investira u novi proces je od značaja pažljivo razmatranje HSE (Health, Safety and Environment) problema na radnom mestu. Zavarivanje trenjem sa mešanjem nudi brojne prednosti u pogledu zaštite zdravlja, životne sredine i bezbednosti na radu u odnosu na druge procese zavarivanja zasnovane na primeni električnog luka. Elektrolučno zavarivanje proizvodi čitav spek-tar ultraljubičastog zra čenja koje je štetno po čovekovo zdravlje, pre svega oči i kožu. Izlaganje ovom zračenju bez adekvatne zaštite može dovesti do ozbiljnih povreda. Ukoliko se ne koriste odgovarajuće mere zaštite, zavarivač vrlo lako može dobiti opekotine. Ovo je naročito izraženo kod elektrolučnog zavarivanja aluminijuma, gde je zbog velike provodljivosti materijala potrebno koristiti električni luk veće energije i čija površina ima veću refleksiju od čelika. Ovaj rad govori o FSW procesu zavarivanja i njegovim prednostima u odnosu na elektrolu čne postupke zavarivanja, sa posebnim osvrtom na zaštitu zdravlja, životne sredine i bezbednosti na radu., In modern industrial production, every manufacturing and assembly process should be assessed with respect to its influence on the environment. For a company that invests in a new process, a careful analysis of HSE problems (Health, Safety and Environment) is very important. Friction stir welding (FSW) process offers numerous advantages regarding health protection, environmental effects and work safety in comparison with other welding procedures, such as arc welding. Arc welding produces a broad spec-trum of UV radiation, harmful for human health (skin, eyes). Exposure to this radiation without an adequate protection can lead to severe injuries. If appropriate protective measures are undertaken, the welder can easily be exposed to heat injuries. This is especially pronounced for arc welding of aluminium alloys, because high material conductivity of Al requires a high-energy arc, and also because its surface has more pronounced reflection than steel. This work deals with the FSW welding process and its advantages in comparison with arc welding processes with respect to health protection, environmental problems and work safety.",
publisher = "Society for Structural Integrity and Life (DIVK)",
journal = "Structural Integrity and Life",
title = "Prednosti zavarivanja trenjem sa mešanjem u odnosu na elektrolučno zavarivanje - zaštita zdravlja i životne sredine i bezbednost na radu, Advantages of friction stir welding over arc welding with respect to health and environmental protection and work safety",
pages = "116-111",
number = "2",
volume = "15",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2893"
}

Veljić, D., Sedmak, A., Rakin, M., Radović, N., Popović, N., Daşcău, H.,& Bajić, N.. (2015). Prednosti zavarivanja trenjem sa mešanjem u odnosu na elektrolučno zavarivanje - zaštita zdravlja i životne sredine i bezbednost na radu. in Structural Integrity and Life
Society for Structural Integrity and Life (DIVK)., 15(2), 111-116.
https://hdl.handle.net/21.15107/rcub_technorep_2893

Veljić D, Sedmak A, Rakin M, Radović N, Popović N, Daşcău H, Bajić N. Prednosti zavarivanja trenjem sa mešanjem u odnosu na elektrolučno zavarivanje - zaštita zdravlja i životne sredine i bezbednost na radu. in Structural Integrity and Life. 2015;15(2):111-116.
https://hdl.handle.net/21.15107/rcub_technorep_2893 .

Veljić, Darko, Sedmak, Aleksandar, Rakin, Marko, Radović, Nenad, Popović, Negica, Daşcău, Horia, Bajić, Nikola, "Prednosti zavarivanja trenjem sa mešanjem u odnosu na elektrolučno zavarivanje - zaštita zdravlja i životne sredine i bezbednost na radu" in Structural Integrity and Life, 15, no. 2 (2015):111-116,
https://hdl.handle.net/21.15107/rcub_technorep_2893 .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Bajić, Nikola
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3016
AB  - The aim of this study was to improve the resistance of turbo jet engine parts exposed to high temperatures and overheating and sudden changes in temperature. For this purpose, three thermal barrier coating (TBC) systems NiCrAlCoY2O3/ZrO2MgO, NiCrAlCoY2O3/ZrO2Y2O3 and NiCrAlCoY2O3/ZrO2CeO2Y2O3 were tested. They were deposited using the atmospheric plasma spray process (APS). In order to develop a TBC with the best thermal insulating properties and the highest reliability in relation to aging of materials under the influence of sudden changes in temperature, TBC systems that were deposited on cold and preheated substrates were tested. The network of microcracks on the surfaces of the ceramic layers in deposited condition was analyzed using scanning electron microscopy (SEM). Insulating characteristics of TBC systems were examined by measuring the temperature difference Delta T between the top and bottom surfaces of the samples at a temperature of 1200 degrees C. Testing of TBC for resistance to thermal cyclic behaviour was performed by exposing samples to alternate heating at 1200 degrees C and rapid cooling of the samples to 180 degrees C. Microhardnesses of the TBC system, after completion of thermal cycles, were compared with the values in deposited state. Analyses of thermal insulation properties and thermal cyclic behaviour have shown a correlation between the substrate temperature and quality of the TBC system in thermal cyclic conditions.
PB  - Elsevier Sci Ltd, Oxford
T2  - Materials & Design
T1  - Experimental study of insulating properties and behaviour of thermal barrier coating systems in thermo cyclic conditions
EP  - 343
SP  - 337
VL  - 67
DO  - 10.1016/j.matdes.2014.11.029
ER  - 

@article{
author = "Mrdak, Mihailo and Rakin, Marko and Međo, Bojan and Bajić, Nikola",
year = "2015",
abstract = "The aim of this study was to improve the resistance of turbo jet engine parts exposed to high temperatures and overheating and sudden changes in temperature. For this purpose, three thermal barrier coating (TBC) systems NiCrAlCoY2O3/ZrO2MgO, NiCrAlCoY2O3/ZrO2Y2O3 and NiCrAlCoY2O3/ZrO2CeO2Y2O3 were tested. They were deposited using the atmospheric plasma spray process (APS). In order to develop a TBC with the best thermal insulating properties and the highest reliability in relation to aging of materials under the influence of sudden changes in temperature, TBC systems that were deposited on cold and preheated substrates were tested. The network of microcracks on the surfaces of the ceramic layers in deposited condition was analyzed using scanning electron microscopy (SEM). Insulating characteristics of TBC systems were examined by measuring the temperature difference Delta T between the top and bottom surfaces of the samples at a temperature of 1200 degrees C. Testing of TBC for resistance to thermal cyclic behaviour was performed by exposing samples to alternate heating at 1200 degrees C and rapid cooling of the samples to 180 degrees C. Microhardnesses of the TBC system, after completion of thermal cycles, were compared with the values in deposited state. Analyses of thermal insulation properties and thermal cyclic behaviour have shown a correlation between the substrate temperature and quality of the TBC system in thermal cyclic conditions.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Materials & Design",
title = "Experimental study of insulating properties and behaviour of thermal barrier coating systems in thermo cyclic conditions",
pages = "343-337",
volume = "67",
doi = "10.1016/j.matdes.2014.11.029"
}

Mrdak, M., Rakin, M., Međo, B.,& Bajić, N.. (2015). Experimental study of insulating properties and behaviour of thermal barrier coating systems in thermo cyclic conditions. in Materials & Design
Elsevier Sci Ltd, Oxford., 67, 337-343.
https://doi.org/10.1016/j.matdes.2014.11.029

Mrdak M, Rakin M, Međo B, Bajić N. Experimental study of insulating properties and behaviour of thermal barrier coating systems in thermo cyclic conditions. in Materials & Design. 2015;67:337-343.
doi:10.1016/j.matdes.2014.11.029 .

Mrdak, Mihailo, Rakin, Marko, Međo, Bojan, Bajić, Nikola, "Experimental study of insulating properties and behaviour of thermal barrier coating systems in thermo cyclic conditions" in Materials & Design, 67 (2015):337-343,
https://doi.org/10.1016/j.matdes.2014.11.029 . .

TY  - JOUR
AU  - Bajić, Nikola
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Stojadinović, Slobodan
AU  - Pekez, Jasmina
AU  - Mrdak, Mihailo
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2615
PB  - DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd
T2  - Zavarivanje i zavarene konstrukcije
T1  - Experimental laboratory for development of fillers and auxiliary materials for welding and soldering (2)
T1  - Eksperimentalna laboratorija za razvoj dodatnih i pomoćnih materijala za zavarivanje i lemljenje (2)
EP  - 9
IS  - 1
SP  - 5
VL  - 59
DO  - 10.5937/zzk1401005B
ER  - 

@article{
author = "Bajić, Nikola and Veljić, Darko and Rakin, Marko and Stojadinović, Slobodan and Pekez, Jasmina and Mrdak, Mihailo",
year = "2014",
publisher = "DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd",
journal = "Zavarivanje i zavarene konstrukcije",
title = "Experimental laboratory for development of fillers and auxiliary materials for welding and soldering (2), Eksperimentalna laboratorija za razvoj dodatnih i pomoćnih materijala za zavarivanje i lemljenje (2)",
pages = "9-5",
number = "1",
volume = "59",
doi = "10.5937/zzk1401005B"
}

Bajić, N., Veljić, D., Rakin, M., Stojadinović, S., Pekez, J.,& Mrdak, M.. (2014). Experimental laboratory for development of fillers and auxiliary materials for welding and soldering (2). in Zavarivanje i zavarene konstrukcije
DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd., 59(1), 5-9.
https://doi.org/10.5937/zzk1401005B

Bajić N, Veljić D, Rakin M, Stojadinović S, Pekez J, Mrdak M. Experimental laboratory for development of fillers and auxiliary materials for welding and soldering (2). in Zavarivanje i zavarene konstrukcije. 2014;59(1):5-9.
doi:10.5937/zzk1401005B .

Bajić, Nikola, Veljić, Darko, Rakin, Marko, Stojadinović, Slobodan, Pekez, Jasmina, Mrdak, Mihailo, "Experimental laboratory for development of fillers and auxiliary materials for welding and soldering (2)" in Zavarivanje i zavarene konstrukcije, 59, no. 1 (2014):5-9,
https://doi.org/10.5937/zzk1401005B . .

TY  - JOUR
AU  - Bajić, Nikola
AU  - Rakin, Marko
AU  - Veljić, Darko
AU  - Mrdak, Mihailo
AU  - Stojadinović, Slobodan
AU  - Pekez, Jasmina
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2617
AB  - This paper presents the results related to organizing production of flux-cored wire alloyed with Ni and Mo according to standard AWS A5.29 intended for the MAG welding process. On the experimental line for steel strip calibration and production of flux-cored wire two batches of flux-cored wire were produced with a constant Mo and Ni content at two levels (1.2% Ni in one and 2.6% Ni in the other batch). Experimental welding of steel plate samples was performed using the MAG process with two qualities of cored wire. Testing the structure and quality of the weld metal was done in order to optimize content of Ni in the alloyed flux-cored wire intended for welding fine grained micro-alloyed steels. Based on the analysis of test results of the microstructure and EDS analysis of the structure of welded samples and test results of tensile properties and impact energy, conclusions were made about the optimal content of Ni in the weld metal, and thus the choice of quality of flux-cored wire.
AB  - U radu su dati rezultati vezani za osvajanje proizvodnje punjene žice legirane sa Ni i Mo prema standardu AWS A5.29 namenjeno za MAG postupak zavarivanja. Na eksperimentalnoj liniji za kalibraciju čelične trake i izradu punjene žice proizvedene su dve šarže punjene žice sa konstantnim sadržajem Mo i sadržajem Ni na dva nivoa (1.2%Ni kod jedne i 2.6%Ni kod druge šarže). Eksperimentalno zavarivanje uzoraka čeličnih ploča je izvedeno MAG postupkom sa dva kvaliteta punjene žice. Ispitivanje strukture i kvaliteta metala šava je izvedeno u cilju optimizacije sadržaja Ni u legiranoj punjenoj žici koja je namenjena za zavarivanje sitnozrnih mikrolegiranih čelika. Na osnovu analize dobijenih rezultata ispitivanja mikrostrukture i EDS analize strukture zavarenih uzoraka i rezultata ispitivanja zateznih karakteristika energije udara, dati su zaključci o optimalnom sadržaju Ni u metalu šava, a time i izboru kvaliteta punjene žice.
PB  - DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd
T2  - Zavarivanje i zavarene konstrukcije
T1  - Optimizing the content of nickel in flux-cored wire intended for welding micro-alloyed steels
T1  - Optimizacija sadržaja nikla u punjenoj žici namenjenoj za zavarivanje mikrolegiranih čelika
EP  - 67
IS  - 2
SP  - 61
VL  - 59
DO  - 10.5937/zzk1402061B
ER  - 

@article{
author = "Bajić, Nikola and Rakin, Marko and Veljić, Darko and Mrdak, Mihailo and Stojadinović, Slobodan and Pekez, Jasmina",
year = "2014",
abstract = "This paper presents the results related to organizing production of flux-cored wire alloyed with Ni and Mo according to standard AWS A5.29 intended for the MAG welding process. On the experimental line for steel strip calibration and production of flux-cored wire two batches of flux-cored wire were produced with a constant Mo and Ni content at two levels (1.2% Ni in one and 2.6% Ni in the other batch). Experimental welding of steel plate samples was performed using the MAG process with two qualities of cored wire. Testing the structure and quality of the weld metal was done in order to optimize content of Ni in the alloyed flux-cored wire intended for welding fine grained micro-alloyed steels. Based on the analysis of test results of the microstructure and EDS analysis of the structure of welded samples and test results of tensile properties and impact energy, conclusions were made about the optimal content of Ni in the weld metal, and thus the choice of quality of flux-cored wire., U radu su dati rezultati vezani za osvajanje proizvodnje punjene žice legirane sa Ni i Mo prema standardu AWS A5.29 namenjeno za MAG postupak zavarivanja. Na eksperimentalnoj liniji za kalibraciju čelične trake i izradu punjene žice proizvedene su dve šarže punjene žice sa konstantnim sadržajem Mo i sadržajem Ni na dva nivoa (1.2%Ni kod jedne i 2.6%Ni kod druge šarže). Eksperimentalno zavarivanje uzoraka čeličnih ploča je izvedeno MAG postupkom sa dva kvaliteta punjene žice. Ispitivanje strukture i kvaliteta metala šava je izvedeno u cilju optimizacije sadržaja Ni u legiranoj punjenoj žici koja je namenjena za zavarivanje sitnozrnih mikrolegiranih čelika. Na osnovu analize dobijenih rezultata ispitivanja mikrostrukture i EDS analize strukture zavarenih uzoraka i rezultata ispitivanja zateznih karakteristika energije udara, dati su zaključci o optimalnom sadržaju Ni u metalu šava, a time i izboru kvaliteta punjene žice.",
publisher = "DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd",
journal = "Zavarivanje i zavarene konstrukcije",
title = "Optimizing the content of nickel in flux-cored wire intended for welding micro-alloyed steels, Optimizacija sadržaja nikla u punjenoj žici namenjenoj za zavarivanje mikrolegiranih čelika",
pages = "67-61",
number = "2",
volume = "59",
doi = "10.5937/zzk1402061B"
}

Bajić, N., Rakin, M., Veljić, D., Mrdak, M., Stojadinović, S.,& Pekez, J.. (2014). Optimizing the content of nickel in flux-cored wire intended for welding micro-alloyed steels. in Zavarivanje i zavarene konstrukcije
DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd., 59(2), 61-67.
https://doi.org/10.5937/zzk1402061B

Bajić N, Rakin M, Veljić D, Mrdak M, Stojadinović S, Pekez J. Optimizing the content of nickel in flux-cored wire intended for welding micro-alloyed steels. in Zavarivanje i zavarene konstrukcije. 2014;59(2):61-67.
doi:10.5937/zzk1402061B .

Bajić, Nikola, Rakin, Marko, Veljić, Darko, Mrdak, Mihailo, Stojadinović, Slobodan, Pekez, Jasmina, "Optimizing the content of nickel in flux-cored wire intended for welding micro-alloyed steels" in Zavarivanje i zavarene konstrukcije, 59, no. 2 (2014):61-67,
https://doi.org/10.5937/zzk1402061B . .

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  - Veljić, Darko
AU  - Sedmak, Aleksandar
AU  - Rakin, Marko
AU  - Radović, Nenad
AU  - Bajić, Nikola
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2342
AB  - The aim of this paper is to analyze changes of vertical force and temperature during friction stir welding process of high strength aluminum alloys (2024 T3). FSW process is a complex nonlinear process accompanied by large plastic deformation, high temperatures and plastic material flow in the welding zone. It is the procedure of material connecting in the so-called solid phase, through the combined action of heat and mechanical work. Analysis of force and temperature changes during the process of welding allows better understanding and control of the process. This paper analyzes the change of force in the vertical direction using a dynamometer and temperature changes on the upper surface of the working panel near the tops of the roller tool using thermal imaging cameras.
AB  - Cilj rada je analiza promene vertikalne sile i temperature tokom procesa zavarivanja trenjem mešanjem (FSW) legura aluminijuma visoke čvrstoće (2024 T3). FSW postupak je složen nelinearan proces praćen velikim plastičnim deformacijama, visokim temperaturama i plastičnim tečenjem materijala u zoni zavarivanja. To je postupak spajanja materijala u tzv. čvrstoj fazi, kombinovanim delovanjem toplote i mehaničkog rada. Analiza promene sile i temperature tokom procesa zavarivanja omogućava bolje razumevanje i kontrolu samog procesa. U radu je analizirana i praćena promena sile u vertikalnom pravcu pomoću dinamometra i promena temperature na gornjoj površini radne ploče u blizini čela valjka alata pomoću termovizijske kamere.
PB  - DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd
T2  - Zavarivanje i zavarene konstrukcije
T1  - Change of temperature and vertical force during friction stir welding
T1  - Promena temperature i vertikalne sile tokom procesa zavarivanja trenjem mešanjem
EP  - 59
IS  - 2
SP  - 53
VL  - 58
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2342
ER  - 

@article{
author = "Veljić, Darko and Sedmak, Aleksandar and Rakin, Marko and Radović, Nenad and Bajić, Nikola",
year = "2013",
abstract = "The aim of this paper is to analyze changes of vertical force and temperature during friction stir welding process of high strength aluminum alloys (2024 T3). FSW process is a complex nonlinear process accompanied by large plastic deformation, high temperatures and plastic material flow in the welding zone. It is the procedure of material connecting in the so-called solid phase, through the combined action of heat and mechanical work. Analysis of force and temperature changes during the process of welding allows better understanding and control of the process. This paper analyzes the change of force in the vertical direction using a dynamometer and temperature changes on the upper surface of the working panel near the tops of the roller tool using thermal imaging cameras., Cilj rada je analiza promene vertikalne sile i temperature tokom procesa zavarivanja trenjem mešanjem (FSW) legura aluminijuma visoke čvrstoće (2024 T3). FSW postupak je složen nelinearan proces praćen velikim plastičnim deformacijama, visokim temperaturama i plastičnim tečenjem materijala u zoni zavarivanja. To je postupak spajanja materijala u tzv. čvrstoj fazi, kombinovanim delovanjem toplote i mehaničkog rada. Analiza promene sile i temperature tokom procesa zavarivanja omogućava bolje razumevanje i kontrolu samog procesa. U radu je analizirana i praćena promena sile u vertikalnom pravcu pomoću dinamometra i promena temperature na gornjoj površini radne ploče u blizini čela valjka alata pomoću termovizijske kamere.",
publisher = "DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd",
journal = "Zavarivanje i zavarene konstrukcije",
title = "Change of temperature and vertical force during friction stir welding, Promena temperature i vertikalne sile tokom procesa zavarivanja trenjem mešanjem",
pages = "59-53",
number = "2",
volume = "58",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2342"
}

Veljić, D., Sedmak, A., Rakin, M., Radović, N.,& Bajić, N.. (2013). Change of temperature and vertical force during friction stir welding. in Zavarivanje i zavarene konstrukcije
DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd., 58(2), 53-59.
https://hdl.handle.net/21.15107/rcub_technorep_2342

Veljić D, Sedmak A, Rakin M, Radović N, Bajić N. Change of temperature and vertical force during friction stir welding. in Zavarivanje i zavarene konstrukcije. 2013;58(2):53-59.
https://hdl.handle.net/21.15107/rcub_technorep_2342 .

Veljić, Darko, Sedmak, Aleksandar, Rakin, Marko, Radović, Nenad, Bajić, Nikola, "Change of temperature and vertical force during friction stir welding" in Zavarivanje i zavarene konstrukcije, 58, no. 2 (2013):53-59,
https://hdl.handle.net/21.15107/rcub_technorep_2342 .

TY  - JOUR
AU  - Bajić, Nikola
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Stojadinović, Slobodan
AU  - Pekez, Jasmina
AU  - Mrdak, Mihailo
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2352
AB  - The development of new materials and their use in construction of modern devices and structures requires the development of fillers and auxiliary materials for their joining. Development and mastering of production of adequate quality fillers in addition to scientific knowledge requires possession of appropriate experimental equipment. The experimental laboratory that has the appropriate technological equipment and devices provides real opportunities for development and mastering of production of new quality fillers and auxiliary materials for welding and soldering.
AB  - Razvoj novih materijala i njihova primena u izradi savremenih uređaja i konstrukcija zahteva razvoj dodatnih i pomoćnih materijala za njihovo spajanje. Razvoj i osvajanje proizvodnje odgovarajućih kvaliteta dodatnih materijala pored naučnih i stručnih saznanja zahteva i posedovanje odgovarajuće eksperimentalne opreme. Eksperimentalna laboratorija koja poseduje odgovarajuću tehnološku opremu i uređaje pruža realne mogućnosti za razvoj i osvajanje proivodnje novih kvaliteta dodatnih i pomoćnih materijala za zavarivanje i lemljenje.
PB  - DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd
T2  - Zavarivanje i zavarene konstrukcije
T1  - Experimental laboratory for development of fillers and auxiliary materials for welding and soldering
T1  - Eksperimentalna laboratorija za razvoj dodatnih i pomoćnih materijala za zavarivanje i lemljenje
EP  - 161
IS  - 4
SP  - 157
VL  - 58
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2352
ER  - 

@article{
author = "Bajić, Nikola and Veljić, Darko and Rakin, Marko and Stojadinović, Slobodan and Pekez, Jasmina and Mrdak, Mihailo",
year = "2013",
abstract = "The development of new materials and their use in construction of modern devices and structures requires the development of fillers and auxiliary materials for their joining. Development and mastering of production of adequate quality fillers in addition to scientific knowledge requires possession of appropriate experimental equipment. The experimental laboratory that has the appropriate technological equipment and devices provides real opportunities for development and mastering of production of new quality fillers and auxiliary materials for welding and soldering., Razvoj novih materijala i njihova primena u izradi savremenih uređaja i konstrukcija zahteva razvoj dodatnih i pomoćnih materijala za njihovo spajanje. Razvoj i osvajanje proizvodnje odgovarajućih kvaliteta dodatnih materijala pored naučnih i stručnih saznanja zahteva i posedovanje odgovarajuće eksperimentalne opreme. Eksperimentalna laboratorija koja poseduje odgovarajuću tehnološku opremu i uređaje pruža realne mogućnosti za razvoj i osvajanje proivodnje novih kvaliteta dodatnih i pomoćnih materijala za zavarivanje i lemljenje.",
publisher = "DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd",
journal = "Zavarivanje i zavarene konstrukcije",
title = "Experimental laboratory for development of fillers and auxiliary materials for welding and soldering, Eksperimentalna laboratorija za razvoj dodatnih i pomoćnih materijala za zavarivanje i lemljenje",
pages = "161-157",
number = "4",
volume = "58",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2352"
}

Bajić, N., Veljić, D., Rakin, M., Stojadinović, S., Pekez, J.,& Mrdak, M.. (2013). Experimental laboratory for development of fillers and auxiliary materials for welding and soldering. in Zavarivanje i zavarene konstrukcije
DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd., 58(4), 157-161.
https://hdl.handle.net/21.15107/rcub_technorep_2352

Bajić N, Veljić D, Rakin M, Stojadinović S, Pekez J, Mrdak M. Experimental laboratory for development of fillers and auxiliary materials for welding and soldering. in Zavarivanje i zavarene konstrukcije. 2013;58(4):157-161.
https://hdl.handle.net/21.15107/rcub_technorep_2352 .

Bajić, Nikola, Veljić, Darko, Rakin, Marko, Stojadinović, Slobodan, Pekez, Jasmina, Mrdak, Mihailo, "Experimental laboratory for development of fillers and auxiliary materials for welding and soldering" in Zavarivanje i zavarene konstrukcije, 58, no. 4 (2013):157-161,
https://hdl.handle.net/21.15107/rcub_technorep_2352 .

TY  - JOUR
AU  - Rakin, Marko
AU  - Bajić, Nikola
AU  - Mrdak, Mihailo
AU  - Veljić, Darko
AU  - Arsić, Miodrag
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2385
AB  - The aim of this study was to master new quality cored wires made of steel strips and the cores filled with metal powders and low molecular hydrophobic compounds. For experimental research, the specimens were made of micro alloyed steel type NIOMOL 490K intended for making welded structures subjected to dynamic loads and effects of low temperature. Welding of test specimens was done using the MAG method in CO2 shielding with two new quality cored wires. The testing included the determination of mechanical properties of the base metal (BM) and the weld metal (WM), which apart from having sufficient strength must also have good toughness. The microstructures of BM, WM and heat affected zone (HAZ) were analysed, due to possible formation of a heterogeneous microstructure, which can reduce toughness. Results of testing of welded joints should define a new quality of cored wires in view of welding-technological characteristics. The results indicate that the new quality cored wires can produce good mechanical-structural properties of welded joints.
PB  - University of Osijek, Tech Fac, Slavonski Brod
T2  - Tehnicki vjesnik-Technical Gazette
T1  - Analysis of mechanical and structural properties of micro alloyed steel welded joints depending on quality of cored wire
EP  - 640
IS  - 4
SP  - 635
VL  - 20
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2385
ER  - 

@article{
author = "Rakin, Marko and Bajić, Nikola and Mrdak, Mihailo and Veljić, Darko and Arsić, Miodrag",
year = "2013",
abstract = "The aim of this study was to master new quality cored wires made of steel strips and the cores filled with metal powders and low molecular hydrophobic compounds. For experimental research, the specimens were made of micro alloyed steel type NIOMOL 490K intended for making welded structures subjected to dynamic loads and effects of low temperature. Welding of test specimens was done using the MAG method in CO2 shielding with two new quality cored wires. The testing included the determination of mechanical properties of the base metal (BM) and the weld metal (WM), which apart from having sufficient strength must also have good toughness. The microstructures of BM, WM and heat affected zone (HAZ) were analysed, due to possible formation of a heterogeneous microstructure, which can reduce toughness. Results of testing of welded joints should define a new quality of cored wires in view of welding-technological characteristics. The results indicate that the new quality cored wires can produce good mechanical-structural properties of welded joints.",
publisher = "University of Osijek, Tech Fac, Slavonski Brod",
journal = "Tehnicki vjesnik-Technical Gazette",
title = "Analysis of mechanical and structural properties of micro alloyed steel welded joints depending on quality of cored wire",
pages = "640-635",
number = "4",
volume = "20",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2385"
}

Rakin, M., Bajić, N., Mrdak, M., Veljić, D.,& Arsić, M.. (2013). Analysis of mechanical and structural properties of micro alloyed steel welded joints depending on quality of cored wire. in Tehnicki vjesnik-Technical Gazette
University of Osijek, Tech Fac, Slavonski Brod., 20(4), 635-640.
https://hdl.handle.net/21.15107/rcub_technorep_2385

Rakin M, Bajić N, Mrdak M, Veljić D, Arsić M. Analysis of mechanical and structural properties of micro alloyed steel welded joints depending on quality of cored wire. in Tehnicki vjesnik-Technical Gazette. 2013;20(4):635-640.
https://hdl.handle.net/21.15107/rcub_technorep_2385 .

Rakin, Marko, Bajić, Nikola, Mrdak, Mihailo, Veljić, Darko, Arsić, Miodrag, "Analysis of mechanical and structural properties of micro alloyed steel welded joints depending on quality of cored wire" in Tehnicki vjesnik-Technical Gazette, 20, no. 4 (2013):635-640,
https://hdl.handle.net/21.15107/rcub_technorep_2385 .

TY  - JOUR
AU  - Perović, Milenko
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Radović, Nenad
AU  - Sedmak, Aleksandar
AU  - Bajić, Nikola
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2012
AB  - This paper defines a set of welding parameters for the Friction-Stir Welding (FSW) of two forged panels of the alloy EN AW 7049A in a T652 temper and discusses the plunge stage of FSW using numerical modeling. This multi-component aluminum alloy is characterized by high strength, reduced plasticity and poor weldability. Observations of the macrostructure and microstructure clearly showed typical zones of a FSW joint and the appropriate grain sizes. The finest grains were observed within the nugget, while the coarsest grains are found to be in the HAZ. The ultimate tensile strength is 80.3 % of the parent material. A coupled thermo-mechanical model was developed to study the temperature fields and the plunge force of the alloy EN AW 7049A under different rotating speeds, (300, 400 and 500) r/min, during the FSW process of the plunge stage. A three-dimensional FE model has been developed in ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson-Cook material law and Coulomb's Law of Friction. Numerical results indicate that the maximum temperature in the FSW process can be increased with an increase in the rotational speed, which can be used to reduce the plunge force.
PB  - Institute of Metals and Technology
T2  - Materiali in Tehnologije
T1  - Friction-stir welding of high-strength aluminium alloys and a numerical simulation of the plunge stage
EP  - 221
IS  - 3
SP  - 215
VL  - 46
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2012
ER  - 

@article{
author = "Perović, Milenko and Veljić, Darko and Rakin, Marko and Radović, Nenad and Sedmak, Aleksandar and Bajić, Nikola",
year = "2012",
abstract = "This paper defines a set of welding parameters for the Friction-Stir Welding (FSW) of two forged panels of the alloy EN AW 7049A in a T652 temper and discusses the plunge stage of FSW using numerical modeling. This multi-component aluminum alloy is characterized by high strength, reduced plasticity and poor weldability. Observations of the macrostructure and microstructure clearly showed typical zones of a FSW joint and the appropriate grain sizes. The finest grains were observed within the nugget, while the coarsest grains are found to be in the HAZ. The ultimate tensile strength is 80.3 % of the parent material. A coupled thermo-mechanical model was developed to study the temperature fields and the plunge force of the alloy EN AW 7049A under different rotating speeds, (300, 400 and 500) r/min, during the FSW process of the plunge stage. A three-dimensional FE model has been developed in ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson-Cook material law and Coulomb's Law of Friction. Numerical results indicate that the maximum temperature in the FSW process can be increased with an increase in the rotational speed, which can be used to reduce the plunge force.",
publisher = "Institute of Metals and Technology",
journal = "Materiali in Tehnologije",
title = "Friction-stir welding of high-strength aluminium alloys and a numerical simulation of the plunge stage",
pages = "221-215",
number = "3",
volume = "46",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2012"
}

Perović, M., Veljić, D., Rakin, M., Radović, N., Sedmak, A.,& Bajić, N.. (2012). Friction-stir welding of high-strength aluminium alloys and a numerical simulation of the plunge stage. in Materiali in Tehnologije
Institute of Metals and Technology., 46(3), 215-221.
https://hdl.handle.net/21.15107/rcub_technorep_2012

Perović M, Veljić D, Rakin M, Radović N, Sedmak A, Bajić N. Friction-stir welding of high-strength aluminium alloys and a numerical simulation of the plunge stage. in Materiali in Tehnologije. 2012;46(3):215-221.
https://hdl.handle.net/21.15107/rcub_technorep_2012 .

Perović, Milenko, Veljić, Darko, Rakin, Marko, Radović, Nenad, Sedmak, Aleksandar, Bajić, Nikola, "Friction-stir welding of high-strength aluminium alloys and a numerical simulation of the plunge stage" in Materiali in Tehnologije, 46, no. 3 (2012):215-221,
https://hdl.handle.net/21.15107/rcub_technorep_2012 .

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 .

TY  - JOUR
AU  - Veljić, Darko
AU  - Perović, Milenko
AU  - Sedmak, Aleksandar
AU  - Rakin, Marko
AU  - Bajić, Nikola
AU  - Međo, Bojan
AU  - Dascau, Horia
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1842
AB  - This paper investigates the plunge stage using numerical modeling. A three-dimensional finite element model (FEM) of the plunge stage is developed using the commercial code ABAQUS to study the thermo-mechanical processes involved during the plunge stage. A coupled thermo-mechanical 3D FE model uses the arbitrary Lagrangian-Eulerian formulation, the Johnson-Cook material law and Coulomb's Law of friction. The model is developed to study the temperature fields of alloy Al2024-T351 under different process parameters (rotating speed) during the friction stir welding (FSW) process. Numerical results indicate that the maximal temperature of the FSW process can be increased with the increase of rotational speed and that temperature is lower than the melting point of the welding material. In this analysis, temperature, displacement, and mechanical responses are determined simultaneously. The heat generation in FSW can be divided into three parts: frictional heat generated by the tool shoulder, frictional heat generated by the tool pin, and heat generated by material deformation near the pin region.
AB  - U ovom radu je istražena faza uranjanja alata primenom numeričkog modeliranja. Trodimenzionalni model konačnih elemenata (FEM) faze uranjanja je razvijen primenom softvera ABAQUS radi proučavanja termomehaničkih procesa koji se odvijaju tokom faze uranjanja. Spregnuti termomehanički 3D FE model se bazira na proizvoljnim formulacijama Lagranža-Ojlera, zakonu materijala Džonson-Kuk i Kulonovom zakonu trenja. Model je razvijen radi proučavanja temperaturskih polja legure Al2024-T351 pod različitim parametrima postupka (brzina rotacije) kod postupka zavarivanja trenjem mešanjem (FSW). Numerički rezultati pokazuju da se maksimalna temperatura postupka FSW može povećati sa povećanjem brzine rotacije, kao i da je temperatura niža od tačke topljenja zavarenog materijala. U ovoj analizi, temperatura, pomeranje i mehanički odzivi se određuju simultano. Izdvajanje toplote kod FSW se može podeliti na tri dela: toplota trenja koja se razvija kretanjem čela alata, toplota trenja dobijena kretanjem trna alata, kao i toplota usled plastične deformacije materijala u blizini oblasti trna alata.
PB  - Society for Structural Integrity and Life, Institute for Material Testing
T2  - Integritet i vek konstrukcija
T1  - Numerical simulation of the plunge stage in friction stir welding
T1  - Numerička simulacija faze uranjanja kod zavarivanja trenjem mešanjem
EP  - 134
IS  - 2
SP  - 131
VL  - 11
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1842
ER  - 

@article{
author = "Veljić, Darko and Perović, Milenko and Sedmak, Aleksandar and Rakin, Marko and Bajić, Nikola and Međo, Bojan and Dascau, Horia",
year = "2011",
abstract = "This paper investigates the plunge stage using numerical modeling. A three-dimensional finite element model (FEM) of the plunge stage is developed using the commercial code ABAQUS to study the thermo-mechanical processes involved during the plunge stage. A coupled thermo-mechanical 3D FE model uses the arbitrary Lagrangian-Eulerian formulation, the Johnson-Cook material law and Coulomb's Law of friction. The model is developed to study the temperature fields of alloy Al2024-T351 under different process parameters (rotating speed) during the friction stir welding (FSW) process. Numerical results indicate that the maximal temperature of the FSW process can be increased with the increase of rotational speed and that temperature is lower than the melting point of the welding material. In this analysis, temperature, displacement, and mechanical responses are determined simultaneously. The heat generation in FSW can be divided into three parts: frictional heat generated by the tool shoulder, frictional heat generated by the tool pin, and heat generated by material deformation near the pin region., U ovom radu je istražena faza uranjanja alata primenom numeričkog modeliranja. Trodimenzionalni model konačnih elemenata (FEM) faze uranjanja je razvijen primenom softvera ABAQUS radi proučavanja termomehaničkih procesa koji se odvijaju tokom faze uranjanja. Spregnuti termomehanički 3D FE model se bazira na proizvoljnim formulacijama Lagranža-Ojlera, zakonu materijala Džonson-Kuk i Kulonovom zakonu trenja. Model je razvijen radi proučavanja temperaturskih polja legure Al2024-T351 pod različitim parametrima postupka (brzina rotacije) kod postupka zavarivanja trenjem mešanjem (FSW). Numerički rezultati pokazuju da se maksimalna temperatura postupka FSW može povećati sa povećanjem brzine rotacije, kao i da je temperatura niža od tačke topljenja zavarenog materijala. U ovoj analizi, temperatura, pomeranje i mehanički odzivi se određuju simultano. Izdvajanje toplote kod FSW se može podeliti na tri dela: toplota trenja koja se razvija kretanjem čela alata, toplota trenja dobijena kretanjem trna alata, kao i toplota usled plastične deformacije materijala u blizini oblasti trna alata.",
publisher = "Society for Structural Integrity and Life, Institute for Material Testing",
journal = "Integritet i vek konstrukcija",
title = "Numerical simulation of the plunge stage in friction stir welding, Numerička simulacija faze uranjanja kod zavarivanja trenjem mešanjem",
pages = "134-131",
number = "2",
volume = "11",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1842"
}

Veljić, D., Perović, M., Sedmak, A., Rakin, M., Bajić, N., Međo, B.,& Dascau, H.. (2011). Numerical simulation of the plunge stage in friction stir welding. in Integritet i vek konstrukcija
Society for Structural Integrity and Life, Institute for Material Testing., 11(2), 131-134.
https://hdl.handle.net/21.15107/rcub_technorep_1842

Veljić D, Perović M, Sedmak A, Rakin M, Bajić N, Međo B, Dascau H. Numerical simulation of the plunge stage in friction stir welding. in Integritet i vek konstrukcija. 2011;11(2):131-134.
https://hdl.handle.net/21.15107/rcub_technorep_1842 .

Veljić, Darko, Perović, Milenko, Sedmak, Aleksandar, Rakin, Marko, Bajić, Nikola, Međo, Bojan, Dascau, Horia, "Numerical simulation of the plunge stage in friction stir welding" in Integritet i vek konstrukcija, 11, no. 2 (2011):131-134,
https://hdl.handle.net/21.15107/rcub_technorep_1842 .

TY  - JOUR
AU  - Bajić, Nikola
AU  - Kovacević, Zorica
AU  - Rakin, Marko
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1748
AB  - This paper presents a selected repair technology for different types of electro-contacts by replacing the contact plates on the brass body of the electro-contacts and connecting the elements by process of brazing with silver solder. Quality assessment of the soldered connection was performed by metallographic examining of the structure soldered connection of the contact plates, hard brazing, and the body of the electro-contacts carrier. Determination of the exploitation period of the repaired electro-contacts is derived by comparison with new electro-contacts in industrial conditions. Analysis of economic and financial data is derived by comparing the costs of reparations and the cost of purchasing new electro-contacts annually in production conditions in the manufacturing Steel Plant - Smederevo. On the basis of investigation of the structure of the soldered connection, the exploitation period and analysis of economic and financial indicators, a feasibility assessment was given of the applied technology of repair of electro-contacts in industrial conditions of the Steel Plant - Smederevo.
T2  - Technics Technologies Education Management
T1  - Technological possibilities and justification of electro-contact rapairing
EP  - 307
IS  - 2
SP  - 300
VL  - 6
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1748
ER  - 

@article{
author = "Bajić, Nikola and Kovacević, Zorica and Rakin, Marko",
year = "2011",
abstract = "This paper presents a selected repair technology for different types of electro-contacts by replacing the contact plates on the brass body of the electro-contacts and connecting the elements by process of brazing with silver solder. Quality assessment of the soldered connection was performed by metallographic examining of the structure soldered connection of the contact plates, hard brazing, and the body of the electro-contacts carrier. Determination of the exploitation period of the repaired electro-contacts is derived by comparison with new electro-contacts in industrial conditions. Analysis of economic and financial data is derived by comparing the costs of reparations and the cost of purchasing new electro-contacts annually in production conditions in the manufacturing Steel Plant - Smederevo. On the basis of investigation of the structure of the soldered connection, the exploitation period and analysis of economic and financial indicators, a feasibility assessment was given of the applied technology of repair of electro-contacts in industrial conditions of the Steel Plant - Smederevo.",
journal = "Technics Technologies Education Management",
title = "Technological possibilities and justification of electro-contact rapairing",
pages = "307-300",
number = "2",
volume = "6",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1748"
}

Bajić, N., Kovacević, Z.,& Rakin, M.. (2011). Technological possibilities and justification of electro-contact rapairing. in Technics Technologies Education Management, 6(2), 300-307.
https://hdl.handle.net/21.15107/rcub_technorep_1748

Bajić N, Kovacević Z, Rakin M. Technological possibilities and justification of electro-contact rapairing. in Technics Technologies Education Management. 2011;6(2):300-307.
https://hdl.handle.net/21.15107/rcub_technorep_1748 .

Bajić, Nikola, Kovacević, Zorica, Rakin, Marko, "Technological possibilities and justification of electro-contact rapairing" in Technics Technologies Education Management, 6, no. 2 (2011):300-307,
https://hdl.handle.net/21.15107/rcub_technorep_1748 .

TY  - JOUR
AU  - Bajić, Nikola
AU  - Rakin, Marko
AU  - Stojadinović, Slobodan
PY  - 2006
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/892
AB  - This paper presents results of repairing a ring part and rolling surfaces of the crane wheel by SAW method with flux cored wire. Optimal quality of flux cored wire for crane wheel repairing is defined by weld metal hardness and results of the repaired wheels behavior in exploitations.
AB  - U radu su dati rezultati ispitivanja kvaliteta navarenog dela venca i površine kotrljanja točka dizalice izvedeni EPP - postupkom sa odabranim metalurškim kvalitetom punjene elektrodne žice. Izbor optimalnog kvaliteta punjene elektrodne žice za navarivanje točka dizalice je izveden na osnovu nivoa vrednosti tvrdoće metala navara koji odgovara tvrdoći kranske staze kao i rezultata dobijenih na osnovu praćenja ponašanja navarenih točkova u eksploataciji.
PB  - DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd
T2  - Zavarivanje i zavarene konstrukcije
T1  - Saw surfacing of the worn part of crane wheel with flux cored wire
T1  - Navarivanje EPP-postupkom istrošenog dela točka dizalice primenom punjene žice
EP  - 150
IS  - 4
SP  - 147
VL  - 51
UR  - https://hdl.handle.net/21.15107/rcub_technorep_892
ER  - 

@article{
author = "Bajić, Nikola and Rakin, Marko and Stojadinović, Slobodan",
year = "2006",
abstract = "This paper presents results of repairing a ring part and rolling surfaces of the crane wheel by SAW method with flux cored wire. Optimal quality of flux cored wire for crane wheel repairing is defined by weld metal hardness and results of the repaired wheels behavior in exploitations., U radu su dati rezultati ispitivanja kvaliteta navarenog dela venca i površine kotrljanja točka dizalice izvedeni EPP - postupkom sa odabranim metalurškim kvalitetom punjene elektrodne žice. Izbor optimalnog kvaliteta punjene elektrodne žice za navarivanje točka dizalice je izveden na osnovu nivoa vrednosti tvrdoće metala navara koji odgovara tvrdoći kranske staze kao i rezultata dobijenih na osnovu praćenja ponašanja navarenih točkova u eksploataciji.",
publisher = "DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd",
journal = "Zavarivanje i zavarene konstrukcije",
title = "Saw surfacing of the worn part of crane wheel with flux cored wire, Navarivanje EPP-postupkom istrošenog dela točka dizalice primenom punjene žice",
pages = "150-147",
number = "4",
volume = "51",
url = "https://hdl.handle.net/21.15107/rcub_technorep_892"
}

Bajić, N., Rakin, M.,& Stojadinović, S.. (2006). Saw surfacing of the worn part of crane wheel with flux cored wire. in Zavarivanje i zavarene konstrukcije
DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd., 51(4), 147-150.
https://hdl.handle.net/21.15107/rcub_technorep_892

Bajić N, Rakin M, Stojadinović S. Saw surfacing of the worn part of crane wheel with flux cored wire. in Zavarivanje i zavarene konstrukcije. 2006;51(4):147-150.
https://hdl.handle.net/21.15107/rcub_technorep_892 .

Bajić, Nikola, Rakin, Marko, Stojadinović, Slobodan, "Saw surfacing of the worn part of crane wheel with flux cored wire" in Zavarivanje i zavarene konstrukcije, 51, no. 4 (2006):147-150,
https://hdl.handle.net/21.15107/rcub_technorep_892 .

TY  - JOUR
AU  - Bajić, Nikola
AU  - Stojadinović, Slobodan
AU  - Rakin, Marko
PY  - 2005
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/745
AB  - In this paper the possibilities of application of flux-cored wire of various metallurgical qualities for welding on the surface of operating parts of agricultural machines in EPP process in order to attain wear-resistance and economy have been presented. The results of comparative analysis of the quality of an on-weld made with two qualities of flux-cored wire using an EPP-device with rectilinear and oscillatory motion of welder head have also been presented.
AB  - U radu su iznesene mogućnosti primene različitih metalurških kvaliteta punjenih elektrodnih lica primenom EPP- postupka za navarivanje površine radnih delova poljoprivrednih mašina u cilju postizanja otpornosti na habanje i ekonomičnosti. Dati su rezultati komparativne analize kvaliteta navara izvedenog sa dva kvaliteta punjene lice na EPP-uređaju sa ravnim i oscilatornim kretanjem zavarivačke glave.
PB  - Naučno društvo za pogonske mašine, traktore i održavanje, Novi Sad i Univerzitet u Novom Sadu - Poljoprivredni fakultet - Institut za poljoprivrednu tehniku, Novi Sad
T2  - Traktori i pogonske mašine
T1  - The application of flux cored wire for welding on the surface of operating parts of agricultural machines
T1  - Primena punjenih žica za navarivanje površine radnih delova poljoprivrednih mašina
EP  - 114
IS  - 4
SP  - 109
VL  - 10
UR  - https://hdl.handle.net/21.15107/rcub_technorep_745
ER  - 

@article{
author = "Bajić, Nikola and Stojadinović, Slobodan and Rakin, Marko",
year = "2005",
abstract = "In this paper the possibilities of application of flux-cored wire of various metallurgical qualities for welding on the surface of operating parts of agricultural machines in EPP process in order to attain wear-resistance and economy have been presented. The results of comparative analysis of the quality of an on-weld made with two qualities of flux-cored wire using an EPP-device with rectilinear and oscillatory motion of welder head have also been presented., U radu su iznesene mogućnosti primene različitih metalurških kvaliteta punjenih elektrodnih lica primenom EPP- postupka za navarivanje površine radnih delova poljoprivrednih mašina u cilju postizanja otpornosti na habanje i ekonomičnosti. Dati su rezultati komparativne analize kvaliteta navara izvedenog sa dva kvaliteta punjene lice na EPP-uređaju sa ravnim i oscilatornim kretanjem zavarivačke glave.",
publisher = "Naučno društvo za pogonske mašine, traktore i održavanje, Novi Sad i Univerzitet u Novom Sadu - Poljoprivredni fakultet - Institut za poljoprivrednu tehniku, Novi Sad",
journal = "Traktori i pogonske mašine",
title = "The application of flux cored wire for welding on the surface of operating parts of agricultural machines, Primena punjenih žica za navarivanje površine radnih delova poljoprivrednih mašina",
pages = "114-109",
number = "4",
volume = "10",
url = "https://hdl.handle.net/21.15107/rcub_technorep_745"
}

Bajić, N., Stojadinović, S.,& Rakin, M.. (2005). The application of flux cored wire for welding on the surface of operating parts of agricultural machines. in Traktori i pogonske mašine
Naučno društvo za pogonske mašine, traktore i održavanje, Novi Sad i Univerzitet u Novom Sadu - Poljoprivredni fakultet - Institut za poljoprivrednu tehniku, Novi Sad., 10(4), 109-114.
https://hdl.handle.net/21.15107/rcub_technorep_745

Bajić N, Stojadinović S, Rakin M. The application of flux cored wire for welding on the surface of operating parts of agricultural machines. in Traktori i pogonske mašine. 2005;10(4):109-114.
https://hdl.handle.net/21.15107/rcub_technorep_745 .

Bajić, Nikola, Stojadinović, Slobodan, Rakin, Marko, "The application of flux cored wire for welding on the surface of operating parts of agricultural machines" in Traktori i pogonske mašine, 10, no. 4 (2005):109-114,
https://hdl.handle.net/21.15107/rcub_technorep_745 .