TY  - JOUR
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Mrdak, Mihailo
AU  - Sedmak, Aleksandar
PY  - 2019
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/3190
AB  - Friction stir welding is one of the procedures for joining the parts in solid state. Thermo-mechanical simulation of the friction stir welding of high-strength aluminium alloys 2024 T3 and 2024 T351 is considered in this work. Numerical models corresponding to the linear welding stage are developed in Abaqus software package. The material behaviour is modelled by Johnson-Cook law (which relates the yield stress with temperature, strain and strain rate), and the Arbitrary Lagrangian-Eulerian technique is applied. The difference in thermo-mechanical behaviour between the two materials has been analysed and commented. The main quantities which are considered are the temperature in the weld area, plastic strain, as well as the rate of heat generation during the welding process.
PB  - Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd
T2  - Thermal Science
T1  - Temperature fields in linear stage of friction stir welding effect of different material properties
EP  - 3992
IS  - 6
SP  - 3985
VL  - 23
DO  - 10.2298/TSCI181015264V
ER  - 

@article{
author = "Veljić, Darko and Rakin, Marko and Međo, Bojan and Mrdak, Mihailo and Sedmak, Aleksandar",
year = "2019",
abstract = "Friction stir welding is one of the procedures for joining the parts in solid state. Thermo-mechanical simulation of the friction stir welding of high-strength aluminium alloys 2024 T3 and 2024 T351 is considered in this work. Numerical models corresponding to the linear welding stage are developed in Abaqus software package. The material behaviour is modelled by Johnson-Cook law (which relates the yield stress with temperature, strain and strain rate), and the Arbitrary Lagrangian-Eulerian technique is applied. The difference in thermo-mechanical behaviour between the two materials has been analysed and commented. The main quantities which are considered are the temperature in the weld area, plastic strain, as well as the rate of heat generation during the welding process.",
publisher = "Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd",
journal = "Thermal Science",
title = "Temperature fields in linear stage of friction stir welding effect of different material properties",
pages = "3992-3985",
number = "6",
volume = "23",
doi = "10.2298/TSCI181015264V"
}

Veljić, D., Rakin, M., Međo, B., Mrdak, M.,& Sedmak, A.. (2019). Temperature fields in linear stage of friction stir welding effect of different material properties. in Thermal Science
Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd., 23(6), 3985-3992.
https://doi.org/10.2298/TSCI181015264V

Veljić D, Rakin M, Međo B, Mrdak M, Sedmak A. Temperature fields in linear stage of friction stir welding effect of different material properties. in Thermal Science. 2019;23(6):3985-3992.
doi:10.2298/TSCI181015264V .

Veljić, Darko, Rakin, Marko, Međo, Bojan, Mrdak, Mihailo, Sedmak, Aleksandar, "Temperature fields in linear stage of friction stir welding effect of different material properties" in Thermal Science, 23, no. 6 (2019):3985-3992,
https://doi.org/10.2298/TSCI181015264V . .

TY  - JOUR
AU  - Vencl, Aleksandar
AU  - Mrdak, Mihailo
AU  - Hvizdos, Pavol
PY  - 2017
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/2707
AB  - The tungsten carbide based WC-Co/NiCrBSi (50/50) and molybdenum based Mo/NiCrBSi (75/25) coatings were investigated under boundary lubricated sliding conditions, and their tribological properties were analysed and compared. These two coatings are in service for a long time, but there are very few papers dealing with their tribological properties, especially in lubricated sliding conditions. The NiCrBSi self-fluxing alloy is one of the popularly used materials for thermal sprayed coating, with relatively high hardness, reasonable wear resistance and high temperature corrosion. Tungsten carbide (WC) is one of the most widely used commercial hard coating materials, and is added to the NiCrBSi coating to improve its hardness and wear resistance. Molybdenum (Mo) is added to the NiCrBSi coating to reduce its coefficient of friction, i.e. to improve its dry sliding wear resistance. The results showed that WC-Co/NiCrBSi coating was more wear resistant, but caused higher wear of the counter-body material. Coefficients of friction were similar for both coatings.
PB  - Fakultet inženjerskih nauka, Kragujevac
T2  - Tribology in Industry
T1  - Tribological properties of WC-Co/NiCrBSi and Mo/NiCrBSi plasma spray coatings under boundary lubrication conditions
EP  - 191
IS  - 2
SP  - 183
VL  - 39
DO  - 10.24874/ti.2017.39.02.04
ER  - 

@article{
author = "Vencl, Aleksandar and Mrdak, Mihailo and Hvizdos, Pavol",
year = "2017",
abstract = "The tungsten carbide based WC-Co/NiCrBSi (50/50) and molybdenum based Mo/NiCrBSi (75/25) coatings were investigated under boundary lubricated sliding conditions, and their tribological properties were analysed and compared. These two coatings are in service for a long time, but there are very few papers dealing with their tribological properties, especially in lubricated sliding conditions. The NiCrBSi self-fluxing alloy is one of the popularly used materials for thermal sprayed coating, with relatively high hardness, reasonable wear resistance and high temperature corrosion. Tungsten carbide (WC) is one of the most widely used commercial hard coating materials, and is added to the NiCrBSi coating to improve its hardness and wear resistance. Molybdenum (Mo) is added to the NiCrBSi coating to reduce its coefficient of friction, i.e. to improve its dry sliding wear resistance. The results showed that WC-Co/NiCrBSi coating was more wear resistant, but caused higher wear of the counter-body material. Coefficients of friction were similar for both coatings.",
publisher = "Fakultet inženjerskih nauka, Kragujevac",
journal = "Tribology in Industry",
title = "Tribological properties of WC-Co/NiCrBSi and Mo/NiCrBSi plasma spray coatings under boundary lubrication conditions",
pages = "191-183",
number = "2",
volume = "39",
doi = "10.24874/ti.2017.39.02.04"
}

Vencl, A., Mrdak, M.,& Hvizdos, P.. (2017). Tribological properties of WC-Co/NiCrBSi and Mo/NiCrBSi plasma spray coatings under boundary lubrication conditions. in Tribology in Industry
Fakultet inženjerskih nauka, Kragujevac., 39(2), 183-191.
https://doi.org/10.24874/ti.2017.39.02.04

Vencl A, Mrdak M, Hvizdos P. Tribological properties of WC-Co/NiCrBSi and Mo/NiCrBSi plasma spray coatings under boundary lubrication conditions. in Tribology in Industry. 2017;39(2):183-191.
doi:10.24874/ti.2017.39.02.04 .

Vencl, Aleksandar, Mrdak, Mihailo, Hvizdos, Pavol, "Tribological properties of WC-Co/NiCrBSi and Mo/NiCrBSi plasma spray coatings under boundary lubrication conditions" in Tribology in Industry, 39, no. 2 (2017):183-191,
https://doi.org/10.24874/ti.2017.39.02.04 . .

TY  - JOUR
AU  - Veljić, Darko
AU  - Sedmak, Aleksandar
AU  - Rakin, Marko
AU  - Radović, Nenad A.
AU  - Popović, N.
AU  - Dascau, Horia
AU  - Bajić, Nikola
PY  - 2015
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/2169
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  - Institut za ispitivanje materijala, Beograd
T2  - Structural Integrity and Life
T1  - Advantages of friction stir welding over arc welding with respect to health and environmental protection and work safety [Prednosti zavarivanja trenjem sa mešanjem u odnosu na elektrolučno zavarivanje - Zaštita zdravlja i životne sredine i bezbednost na r
EP  - 116
IS  - 2
SP  - 111
VL  - 15
UR  - https://hdl.handle.net/21.15107/rcub_machinery_2169
ER  - 

@article{
author = "Veljić, Darko and Sedmak, Aleksandar and Rakin, Marko and Radović, Nenad A. and Popović, N. and Dascau, Horia and Bajić, Nikola",
year = "2015",
abstract = "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 = "Institut za ispitivanje materijala, Beograd",
journal = "Structural Integrity and Life",
title = "Advantages of friction stir welding over arc welding with respect to health and environmental protection and work safety [Prednosti zavarivanja trenjem sa mešanjem u odnosu na elektrolučno zavarivanje - Zaštita zdravlja i životne sredine i bezbednost na r",
pages = "116-111",
number = "2",
volume = "15",
url = "https://hdl.handle.net/21.15107/rcub_machinery_2169"
}

Veljić, D., Sedmak, A., Rakin, M., Radović, N. A., Popović, N., Dascau, H.,& Bajić, N.. (2015). Advantages of friction stir welding over arc welding with respect to health and environmental protection and work safety [Prednosti zavarivanja trenjem sa mešanjem u odnosu na elektrolučno zavarivanje - Zaštita zdravlja i životne sredine i bezbednost na r. in Structural Integrity and Life
Institut za ispitivanje materijala, Beograd., 15(2), 111-116.
https://hdl.handle.net/21.15107/rcub_machinery_2169

Veljić D, Sedmak A, Rakin M, Radović NA, Popović N, Dascau H, Bajić N. Advantages of friction stir welding over arc welding with respect to health and environmental protection and work safety [Prednosti zavarivanja trenjem sa mešanjem u odnosu na elektrolučno zavarivanje - Zaštita zdravlja i životne sredine i bezbednost na r. in Structural Integrity and Life. 2015;15(2):111-116.
https://hdl.handle.net/21.15107/rcub_machinery_2169 .

Veljić, Darko, Sedmak, Aleksandar, Rakin, Marko, Radović, Nenad A., Popović, N., Dascau, Horia, Bajić, Nikola, "Advantages of friction stir welding over arc welding with respect to health and environmental protection and work safety [Prednosti zavarivanja trenjem sa mešanjem u odnosu na elektrolučno zavarivanje - Zaštita zdravlja i životne sredine i bezbednost na r" in Structural Integrity and Life, 15, no. 2 (2015):111-116,
https://hdl.handle.net/21.15107/rcub_machinery_2169 .

TY  - JOUR
AU  - Veljić, Darko
AU  - Sedmak, Aleksandar
AU  - Rakin, Marko
AU  - Radović, Nenad A.
AU  - Bajić, Nikola
PY  - 2013
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1613
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.
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.
PB  - DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd
T2  - Zavarivanje i zavarene konstrukcije
T1  - Promena temperature i vertikalne sile tokom procesa zavarivanja trenjem mešanjem
T1  - Change of temperature and vertical force during friction stir welding
EP  - 59
IS  - 2
SP  - 53
VL  - 58
UR  - https://hdl.handle.net/21.15107/rcub_machinery_1613
ER  - 

@article{
author = "Veljić, Darko and Sedmak, Aleksandar and Rakin, Marko and Radović, Nenad A. and Bajić, Nikola",
year = "2013",
abstract = "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., 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.",
publisher = "DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd",
journal = "Zavarivanje i zavarene konstrukcije",
title = "Promena temperature i vertikalne sile tokom procesa zavarivanja trenjem mešanjem, Change of temperature and vertical force during friction stir welding",
pages = "59-53",
number = "2",
volume = "58",
url = "https://hdl.handle.net/21.15107/rcub_machinery_1613"
}

Veljić, D., Sedmak, A., Rakin, M., Radović, N. A.,& Bajić, N.. (2013). Promena temperature i vertikalne sile tokom procesa zavarivanja trenjem mešanjem. in Zavarivanje i zavarene konstrukcije
DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd., 58(2), 53-59.
https://hdl.handle.net/21.15107/rcub_machinery_1613

Veljić D, Sedmak A, Rakin M, Radović NA, Bajić N. Promena temperature i vertikalne sile tokom procesa zavarivanja trenjem mešanjem. in Zavarivanje i zavarene konstrukcije. 2013;58(2):53-59.
https://hdl.handle.net/21.15107/rcub_machinery_1613 .

Veljić, Darko, Sedmak, Aleksandar, Rakin, Marko, Radović, Nenad A., Bajić, Nikola, "Promena temperature i vertikalne sile tokom procesa zavarivanja trenjem mešanjem" in Zavarivanje i zavarene konstrukcije, 58, no. 2 (2013):53-59,
https://hdl.handle.net/21.15107/rcub_machinery_1613 .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Vencl, Aleksandar
AU  - Nedeljković, B. D.
AU  - Stanković, Miloš
PY  - 2013
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1686
AB  - The aim of the present study is to investigate the influence of plasma spay deposition parameters on various properties of two standard thermal barrier coating (TBC) systems deposited on the steel substrate. Two TBC systems were investigated: NiCr-Al-Co-Y2O3/ZrO2-Y2O3 and NiCr-Al-Co-Y2O3/ZrO2-CeO2-Y2O3. Powders were deposited by atmospheric plasma spraying (APS) with two variable parameters. The first variable was substrate temperature (21-23 and 160-180 degrees C), and the second variable was transverse speed of the spraying gun (250 and 500 mm s(-1)), i.e. coating thickness per one pass of the spraying gun. The quality assessments of TBC systems were made on the base of their microstructure, microhardness, tensile bond strength and thermal cyclic behaviour (thermal insulation properties and thermal cycling fatigue). Analysis of the results showed great influence of plasma spray deposition parameters on the quality of obtained TBCs.
PB  - Taylor & Francis Ltd, Abingdon
T2  - Materials Science and Technology
T1  - Influence of plasma spraying parameters on properties of thermal barrier coatings
EP  - 567
IS  - 5
SP  - 559
VL  - 29
DO  - 10.1179/1743284712Y.0000000193
ER  - 

@article{
author = "Mrdak, Mihailo and Vencl, Aleksandar and Nedeljković, B. D. and Stanković, Miloš",
year = "2013",
abstract = "The aim of the present study is to investigate the influence of plasma spay deposition parameters on various properties of two standard thermal barrier coating (TBC) systems deposited on the steel substrate. Two TBC systems were investigated: NiCr-Al-Co-Y2O3/ZrO2-Y2O3 and NiCr-Al-Co-Y2O3/ZrO2-CeO2-Y2O3. Powders were deposited by atmospheric plasma spraying (APS) with two variable parameters. The first variable was substrate temperature (21-23 and 160-180 degrees C), and the second variable was transverse speed of the spraying gun (250 and 500 mm s(-1)), i.e. coating thickness per one pass of the spraying gun. The quality assessments of TBC systems were made on the base of their microstructure, microhardness, tensile bond strength and thermal cyclic behaviour (thermal insulation properties and thermal cycling fatigue). Analysis of the results showed great influence of plasma spray deposition parameters on the quality of obtained TBCs.",
publisher = "Taylor & Francis Ltd, Abingdon",
journal = "Materials Science and Technology",
title = "Influence of plasma spraying parameters on properties of thermal barrier coatings",
pages = "567-559",
number = "5",
volume = "29",
doi = "10.1179/1743284712Y.0000000193"
}

Mrdak, M., Vencl, A., Nedeljković, B. D.,& Stanković, M.. (2013). Influence of plasma spraying parameters on properties of thermal barrier coatings. in Materials Science and Technology
Taylor & Francis Ltd, Abingdon., 29(5), 559-567.
https://doi.org/10.1179/1743284712Y.0000000193

Mrdak M, Vencl A, Nedeljković BD, Stanković M. Influence of plasma spraying parameters on properties of thermal barrier coatings. in Materials Science and Technology. 2013;29(5):559-567.
doi:10.1179/1743284712Y.0000000193 .

Mrdak, Mihailo, Vencl, Aleksandar, Nedeljković, B. D., Stanković, Miloš, "Influence of plasma spraying parameters on properties of thermal barrier coatings" in Materials Science and Technology, 29, no. 5 (2013):559-567,
https://doi.org/10.1179/1743284712Y.0000000193 . .

TY  - JOUR
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Perović, Milenko M.
AU  - Međo, Bojan
AU  - Radaković, Zoran
AU  - Todorović, Petar
AU  - Pavišić, Mirko N.
PY  - 2013
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1666
AB  - This paper deals with the heat generation in the Al alloy Al2024-T3 plate under different rotating speeds and plunge speeds during the plunge stage of friction stir welding. A 3-D finite element model is developed in the commercial code ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson- Cook material law, and Coulomb’s Law of friction. The heat generation in friction stir welding can be divided into two parts: frictional heat generated by the tool and heat generated by material deformation near the pin and the tool shoulder region. Numerical results obtained in this work indicate a more prominent influence from the friction-generated heat. The slip rate of the tool relative to the workpiece material is related to this portion of heat. The material velocity, on the other hand, is related to the heat generated by plastic deformation. Increasing the plunging speed of the tool decreases the friction-generated heat and increases the amount of deformation-generated heat, while increasing the tool rotating speed has the opposite influence on both heat portions. Numerical results are compared with the experimental ones, in order to validate the numerical model, and a good agreement is obtained.
PB  - Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd
T2  - Thermal Science
T1  - Heat generation during plunge stage in friction stir welding
EP  - 496
IS  - 2
SP  - 489
VL  - 17
DO  - 10.2298/TSCI120301205V
ER  - 

@article{
author = "Veljić, Darko and Rakin, Marko and Perović, Milenko M. and Međo, Bojan and Radaković, Zoran and Todorović, Petar and Pavišić, Mirko N.",
year = "2013",
abstract = "This paper deals with the heat generation in the Al alloy Al2024-T3 plate under different rotating speeds and plunge speeds during the plunge stage of friction stir welding. A 3-D finite element model is developed in the commercial code ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson- Cook material law, and Coulomb’s Law of friction. The heat generation in friction stir welding can be divided into two parts: frictional heat generated by the tool and heat generated by material deformation near the pin and the tool shoulder region. Numerical results obtained in this work indicate a more prominent influence from the friction-generated heat. The slip rate of the tool relative to the workpiece material is related to this portion of heat. The material velocity, on the other hand, is related to the heat generated by plastic deformation. Increasing the plunging speed of the tool decreases the friction-generated heat and increases the amount of deformation-generated heat, while increasing the tool rotating speed has the opposite influence on both heat portions. Numerical results are compared with the experimental ones, in order to validate the numerical model, and a good agreement is obtained.",
publisher = "Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd",
journal = "Thermal Science",
title = "Heat generation during plunge stage in friction stir welding",
pages = "496-489",
number = "2",
volume = "17",
doi = "10.2298/TSCI120301205V"
}

Veljić, D., Rakin, M., Perović, M. M., Međo, B., Radaković, Z., Todorović, P.,& Pavišić, M. N.. (2013). Heat generation during plunge stage in friction stir welding. in Thermal Science
Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd., 17(2), 489-496.
https://doi.org/10.2298/TSCI120301205V

Veljić D, Rakin M, Perović MM, Međo B, Radaković Z, Todorović P, Pavišić MN. Heat generation during plunge stage in friction stir welding. in Thermal Science. 2013;17(2):489-496.
doi:10.2298/TSCI120301205V .

Veljić, Darko, Rakin, Marko, Perović, Milenko M., Međo, Bojan, Radaković, Zoran, Todorović, Petar, Pavišić, Mirko N., "Heat generation during plunge stage in friction stir welding" in Thermal Science, 17, no. 2 (2013):489-496,
https://doi.org/10.2298/TSCI120301205V . .